How many grams of solid sodium cyanide should be added to 0.500 L of a 0.174M hydrocyanic acid solution to prepare a buffer with a pH of 8.730 ? ( Ka​(HCN)=4.00×10−10) Mass =g​

Answers

Answer 1

63.4845 grams of solid sodium cyanide should be added to 0.500 L of a 0.174M hydrocyanic acid solution to prepare a buffer with a pH of 8.730.

For preparing a buffer with a specific pH, we can use the Henderson-Hasselbalch equation for acidic buffers:

pH = pKa + log([A-]/[HA])

In this case, the acid is hydrocyanic acid (HCN) and its conjugate base is cyanide ion (CN-).

pH = 8.730

Ka (HCN) = 4.00 × 10^(-10)

Volume (V) = 0.500 L

Concentration of hydrocyanic acid ([HA]) = 0.174 M

To find the concentration of the conjugate base ([A-]), we rearrange the Henderson-Hasselbalch equation:

[A-]/[HA] = 10^(pH - pKa)

Substituting the given values:

[tex][A-]/[0.174] = 10^{8.730} - (-log10(4.00 * 10^{-10})))[/tex]

[tex][A-]/[0.174] = 10^{8.730 + 10}[/tex]

[A-]/[0.174] = [tex]10^{18.730}[/tex]

[A-] =  [tex]10^{18.730}[/tex] * [0.174]

[A-] ≈ 2.593 M

Now, we need to calculate the number of moles of cyanide ion (CN-) required to achieve a concentration of 2.593 M in a volume of 0.500 L:

moles of CN- = [A-] * V

            = 2.593 * 0.500

            = 1.2965 moles

The molar mass of sodium cyanide (NaCN) is approximately 49 g/mol. Therefore, the mass of solid sodium cyanide required can be calculated:

mass = moles of CN- * molar mass of NaCN

     = 1.2965 * 49

     ≈ 63.4845 grams

Rounded to three significant figures, the mass of solid sodium cyanide required to prepare the buffer is approximately 63.5 grams.

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Related Questions

Is this a correct name for an ester

3-ethylpentyl-3-methylhexanoate



Answers

"3-ethylpentyl-3-methylhexanoate" is a correct name for an ester.

Naming an ester

In the given name, "3-ethylpentyl" indicates that there is an ethyl group  attached to the third carbon atom of the pentyl chain (a five-carbon chain). "3-methylhexanoate" indicates that there is a methyl group attached to the third carbon atom of the hexanoate chain (a six-carbon chain).

Thus we can see that the -oate that is part of the name is the primary indication that what we are dealing with here has to be an ester as shown

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c) Why do scientists now think the possibility of life on the
surface of Mars is negligible?
d) How do greenhouse gases (like CO2, H2O and CH4) affect planet
surface temperatures?

Answers

Scientists now consider the possibility of life on the surface of Mars as negligible primarily due to the harsh environmental conditions.

Greenhouse gases in the atmosphere absorb and re-radiate some of this heat energy, trapping it and preventing it from escaping into space and, hence reducing temperatures.

Mars has a thin atmosphere, which provides little protection from harmful radiation from the Sun and cosmic rays. The average surface temperature on Mars is also extremely cold, reaching as low as -80 degrees Celsius (-112 degrees Fahrenheit) in some regions.

Additionally, the atmosphere on Mars is composed mostly of carbon dioxide and lacks sufficient oxygen for complex life forms to survive. These factors, along with the lack of liquid water and the absence of known organic molecules, make it highly unlikely for life as we know it to exist on the surface of Mars.

Greenhouse gases, such as carbon dioxide (CO₂), water vapor (H₂O), and methane (CH₄), play a significant role in regulating the surface temperatures of planets, including Earth. These gases act as a natural "blanket" in the atmosphere, allowing sunlight to penetrate but trapping a portion of the outgoing heat radiation.

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The IR spectrum of a sample contains absorptions at 3080, 2950, and 1660 cm-1. To what class of organic compound does this sample most likely belong?

Answers

The observed absorptions at 3080, 2950, and 1660 cm-1 suggest that the sample most likely belongs to the class of carbonyl compounds.

Based on the given absorptions in the IR spectrum, the sample is likely to belong to the class of carbonyl compounds. The absorption at 3080 cm-1 indicates the presence of sp2 hybridized C-H stretching, which is commonly observed in carbonyl compounds such as aldehydes and ketones. The absorption at 2950 cm-1 corresponds to the sp3 hybridized C-H stretching, which is also consistent with carbonyl compounds. Lastly, the absorption at 1660 cm-1 indicates the presence of a C=O double bond, which is a characteristic feature of carbonyl compounds. Therefore, based on the given absorptions, it can be inferred that the sample is most likely a carbonyl compound.

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When the following solutions are mixed together, what precipitate (if any) will form? (If no precipitate forms, enter wONE,) (a) FeSO 4
(aq)+KCI(aq) (b) Al(NO 3
) 3
(aC)+BA(OH) 2
(Ba) (c) CaCl 2
(aq)+Na 2
5O 4
(a0) K 2
S(aq)+Ni(NO 3
) 2
(aq)

Answers

The precipitate will form in solutions of option b, c and d.

Option A -

The reaction between Fe[tex] SO_{4}[/tex] and KCl will form product Fe[tex] Cl_{2}[/tex], which will dissociate into ions and hence is soluble in water. Thus, no precipitate formation.

Option B -

Reaction between Al [tex]( NO_{3})_{3}[/tex] and Ba [tex] OH_{2}[/tex] will form Al [tex] OH_{2}[/tex] which is insoluble in water this leading to precipitate.

Option C -

Ca [tex] Cl_{2}[/tex] and [tex] Na_{2}[/tex] [tex] SO_{4}[/tex] will react to form calcium sulfate that will appear as white precipitate.

Option D -

[tex] K_{2}[/tex] S + Ni [tex](NO_{3})_{2}[/tex] will react to yield nickel sulfide, an insoluble product. Hence, it will also form precipitate.

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We proceeded with the evaporation of 25L of a sugar solution (342g/mol), with an initial concentration of 0.836M (density 1.1094g/mol), which was carried out in two days:
On the first day, a solution with a density of 1.1244g/mL was obtained.
in the second evaporation a final solution with a density of 1.1359g/mL was obtained
The specification that the solution is required to have is that it has a concentration of 1.376m

Answers

The evaporation of a 25L sugar solution (0.836M, 1.1094g/mol) resulted in a final solution with a density of 1.1359g/mL. To meet the required concentration of 1.376M, approximately 4,181.6g of water needs to be added to compensate for the lost volume during evaporation.

To determine the evaporation process and the required adjustments, let's calculate the number of moles of sugar present in the initial solution and the final volume of the solution after evaporation.

Initial moles of sugar:

Molarity (M) = moles/volume(L)

0.836 M = moles/25 L

moles = 0.836 M * 25 L = 20.9 mol

Initial mass of sugar:

Mass = moles * molar mass

Mass = 20.9 mol * 342 g/mol = 7,137.8 g

Final volume of the solution after evaporation:

Density = mass/volume

1.1359 g/mL = 7,137.8 g/volume_final

volume_final = 7,137.8 g / 1.1359 g/mL = 6,284.4 mL = 6.2844 L

To achieve a final concentration of 1.376 M, we need to find the mass of sugar required and subtract the mass lost during evaporation.

Final moles of sugar:

Molarity = moles/volume_final

1.376 M = moles/6.2844 L

moles = 1.376 M * 6.2844 L = 8.6393 mol

Final mass of sugar:

Mass = moles * molar mass

Mass = 8.6393 mol * 342 g/mol = 2,956.2 g

Mass lost during evaporation:

Initial mass - Final mass = 7,137.8 g - 2,956.2 g = 4,181.6 g

Therefore, during the evaporation process, approximately 4,181.6 g of water was lost.

To meet the required specification, you would need to add water to the final solution to make up for the lost volume and achieve the desired concentration of 1.376 M.

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Complete question:

During the evaporation process of a 25L sugar solution (342g/mol) with an initial concentration of 0.836M (density 1.1094g/mol), a final solution with a density of 1.1359g/mL was obtained. To achieve a desired concentration of 1.376M, how much water needs to be added to compensate for the lost volume and meet the specified concentration?

Calculate the density of \( \mathrm{NO}_{2} \) gas at \( 0.980 \mathrm{~atm} \) and \( 38^{\circ} \mathrm{C} \). Express your answer using three significant figures. Part B Calculate the molar mass of

Answers

The density of NO2 gas at 0.980 atm and 38°C is approximately 2.26 g/L, and the molar mass of NO2 is 46.01 g/mol.

the density of \( \mathrm{NO}_2 \) gas at \( 0.980 \) atm and \( 38^\circ \mathrm{C} \), we can use the ideal gas law and the formula for density. The ideal gas law equation is:

\[ PV = nRT \]

where \( P \) is the pressure, \( V \) is the volume, \( n \) is the number of moles, \( R \) is the ideal gas constant, and \( T \) is the temperature in Kelvin.

First, we need to convert the temperature to Kelvin by adding \( 273.15 \):

\[ T = 38 + 273.15 = 311.15 \mathrm{~K} \]

We also know that the molar volume of any gas at STP (standard temperature and pressure) is \( 22.4 \) L/mol.

Next, we rearrange the ideal gas law equation to solve for the number of moles:

\[ n = \frac{{PV}}{{RT}} \]

Substituting the given values:

\[ n = \frac{{0.980 \times 22.4}}{{0.0821 \times 311.15}} \approx 0.951 \mathrm{~mol} \]

Now, we can calculate the molar mass using the formula:

\[ \text{{Molar mass}} = \frac{{\text{{Mass}}}}{{\text{{moles}}}} \]

The molar mass of \( \mathrm{NO}_2 \) is approximately \( 46.01 \) g/mol.

Therefore, the molar mass of \( \mathrm{NO}_2 \) is \( 46.01 \) g/mol.

The question mentioned Part B, but there was no specific instruction or information given for Part B.

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A balloon is filled to a volume of 7.10L at à temperature of 27.1°C. If the pressure in the balloon is measured to be 2.20 atm, how many moles of gas are contained inside the balloon?

Answers

The number of moles of gas contained inside the balloon is 0.211 mol.

To calculate the number of moles of gas, we can use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.

First, we need to convert the given temperature from Celsius to Kelvin by adding 273.15:

T = 27.1°C + 273.15 = 300.25 K

Next, we rearrange the ideal gas law equation to solve for n:

n = PV / RT

Plugging in the values, we have:

n = (2.20 atm) * (7.10 L) / (0.0821 atm·L/mol·K * 300.25 K) ≈ 0.211 mol

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which of the following will have the highest 5th ionization level: Te, Kr, As, Si

Answers

Te will have the highest 5th ionization level among the given elements.

The ionization energy is the energy required to remove an electron from an atom or ion. Generally, ionization energy increases as you remove successive electrons from an element.

Among the given elements, Te (Tellurium) will have the highest 5th ionization level. This means that it will require the most energy to remove the 5th electron from a Te atom or ion compared to Kr (Krypton), As (Arsenic), and Si (Silicon). The ionization energy tends to increase as you move across a period in the periodic table and decrease as you move down a group. Since Te is further to the right in the periodic table compared to the other elements, it will have a higher ionization energy and thus a higher 5th ionization level.

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Arrange the following biopolymers in order of their increasing thermodynamic stability: Protein, DNA, RNA A. Least stable: Protein < DNA < RNA: Most stable. B. Least stable: RNA < DNA < Protein: Most stable. c. Least stable: DNA < RNA < Protein: Most stable. D. Least stable: Protein < RNA < DNA: Most stable. E. Least stable: RNA < Protein < DNA: Most stable.

Answers

Least stable: DNA < RNA < Protein: Most stable. The correct option is:

C.

The answer is based on the relative thermodynamic stability of the given biopolymers. Proteins are composed of amino acids and have complex three-dimensional structures, making them more thermodynamically stable compared to DNA and RNA.

DNA and RNA, on the other hand, are nucleic acids that are involved in genetic information storage and transfer. DNA is double-stranded and more stable than RNA, which is single-stranded.

This is because the double-stranded structure of DNA provides greater stability due to complementary base pairing.

Therefore, in terms of increasing thermodynamic stability, DNA is less stable than RNA, and RNA is less stable than proteins.The correct option is C.

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assuming both forward and reverse reactions are elementary processes, which reaction has the larger rate constant: the forward or the reverse reaction? match the words in the left column to the appropriate blanks in the sentences on the right.

Answers

If the equilibrium constant (Kc) has a value of 3.1 × 10⁻⁴ (which is much less than one), we would expect the rate constant (k) to be larger than kr.

Matching the words to the appropriate blanks:

smaller Kc: much less than one

k: larger

kr: much more than zero

Assuming both the forward and reverse reactions are elementary reactions, we can make some general observations about the relationship between the rate constants (k and kr) and the equilibrium constant (Kc).

The equilibrium constant (Kc) is related to the rate constants of the forward (k) and reverse (kr) reactions through the equation:

Kc = k/kr

Comparing the values, we can draw the following conclusions:

If Kc is much less than one (<<1), then the value of k is larger than kr. This implies that the forward reaction is faster than the reverse reaction, leading to a higher rate constant (k) compared to kr.

If Kc is much larger than one (>>1), then the value of kr is larger than k. This implies that the reverse reaction is faster than the forward reaction, resulting in a higher rate constant (kr) compared to k.

If Kc is much closer to one, there is no definitive conclusion about the relationship between the rate constants. We would need specific numerical values of Kc, k, and kr to make further determinations.

Therefore, based on the given information, if the equilibrium constant (Kc) has a value of 3.1 × 10⁻⁴ (which is much less than one), we would expect the rate constant (k) to be larger than kr.

Matching the words to the appropriate blanks:

smaller Kc: much less than one

k: larger

kr: much more than zero

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erface/acelus einemClassiD-12683046
The system below was at equilibrium and
then some SO3 gas was removed from the
container. What change will occur for the
system?
2SO2(g) + O₂(g) = 2SO3(g) + 198 kJ

Answers

When some [tex]SO_3[/tex] gas is removed from the container, the system responds by shifting the equilibrium towards the forward reaction, resulting in an additional production of [tex]SO_3[/tex] to restore equilibrium.

Le Chartelier's principle

When some [tex]SO_3[/tex] gas is removed from the container, the equilibrium of the system will be disturbed. According to Le Chatelier's principle, the system will respond to counteract the change and restore equilibrium.

In this case, by removing  [tex]SO_3[/tex] gas from the container, the concentration of  [tex]SO_3[/tex] will decrease. To restore equilibrium, the reaction will shift in the forward direction to produce more  [tex]SO_3[/tex] gas.

This means that more [tex]SO_2[/tex] and [tex]O_2[/tex] will react to form additional  [tex]SO_3[/tex]. The forward reaction is exothermic, so it will also help to offset the removal of heat caused by the decrease in  [tex]SO_3[/tex] concentration.

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Outlining your reasoning clearly determine the point group to which each of the following molecules (i) to (v) belong: (i) CO2

(ii) B(OH)3

(iii) CH4

(iv) Ferrocene (staggered) (v) para-dibromobenzene

Answers

(i) CO2: D∞h, (ii) B(OH)3: C3v, (iii) CH4: Td, (iv) Ferrocene (staggered): D5d, (v) para-dibromobenzene: D2h.

(i) CO2: Carbon dioxide (CO2) belongs to the point group D∞h. This is because CO2 has a linear molecular geometry with a central carbon atom bonded to two oxygen atoms.

The symmetry elements of D∞h include a C∞ rotation axis along the molecular axis, a σh plane perpendicular to the molecular axis, and a σv plane containing the carbon atom and one oxygen atom.

(ii) B(OH)3: Boron trihydroxide (B(OH)3) belongs to the point group C3v. The molecule has a trigonal planar geometry with the boron atom at the center and three hydroxyl groups surrounding it.

The symmetry elements of C3v include a C3 rotation axis passing through the boron atom, three σv planes containing the rotation axis, and a vertical mirror plane (σh) that bisects the molecule.

(iii) CH4: Methane (CH4) belongs to the point group Td. It has a tetrahedral molecular geometry, with the carbon atom at the center and four hydrogen atoms bonded to it.

The symmetry elements of Td include a C3 rotation axis passing through the carbon atom and three perpendicular C2 rotation axes passing through the carbon-hydrogen bonds.

(iv) Ferrocene (staggered): Staggered ferrocene belongs to the point group D5d. It consists of a central iron atom sandwiched between two cyclopentadienyl (Cp) rings.

The staggered conformation exhibits a five-fold rotational symmetry (C5 axis) passing through the iron atom, as well as additional symmetry elements such as vertical mirror planes (σv) bisecting the Cp rings and a horizontal mirror plane (σh) containing the iron atom.

(v) para-dibromobenzene: para-Dibromobenzene belongs to the point group D2h. The molecule consists of a benzene ring with two bromine atoms substituted in the para positions.

It possesses a horizontal mirror plane (σh) passing through the middle of the molecule, a vertical mirror plane (σv) containing the bromine atoms, a C2 rotation axis perpendicular to the σv plane, and an inversion center.

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please answer all questions. Thank you very much for your time! I
will be sure to give a thumbs up raining when you are done (:
1. (2 pts) Which statements are TRUE about catalysts? Select all that apply. A catalyst is a reactant in a chemical reaction. Enzymes are catalysts for biological chemical reactions. Catalysts are use

Answers

Catalysts are substances that increase the rate of a chemical reaction without being consumed by the reaction (option 1,2, and 3).

Enzymes are biological catalysts that increase the rate of chemical reactions in living organisms. Catalysts can be solid, liquid, or gaseous and can change the mechanism of a chemical reaction by lowering its activation energy.

Given below are the true statements about catalysts:1. Enzymes are catalysts for biological chemical reactions.2. Catalysts increase the rate of a chemical reaction.3. Catalysts are not consumed by the reaction.

Therefore, options 1, 2, and 3 are true statements about catalysts.

The complete question is:

Which of the following statements is true about catalysts?

1. Catalysts slow down the rate of chemical reactions.

2. All catalysts are enzymes.

3. Catalysts are used up during a chemical reaction.

4. Catalysts lower the activation energy of a chemical reaction.

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suppose the ir spectrum of your crude product shows peaks at 1691 cm-1 and 1702 cm-1. what does this indicate about your crude product? (you may refer to the ir spectra of the starting materials provided in the previous question)

Answers

If the IR spectrum of a crude product shows peaks at 1691 cm⁻¹ and 1702 cm⁻¹, the peak corresponds to the presence of a carbonyl group (C=O).

The carbonyl group is a functional group that is responsible for many of its chemical and physical properties. The C=O bond absorbs infrared radiation in this region, resulting in a characteristic peak. The intensity and shape of the peak provide information about the strength of the bond, its environment, and the presence of any neighboring functional groups. This information is important in determining the identity of the compound and its structure, as well as for studying the chemical reactions and interactions involving the carbonyl group.

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Methanol (CH3​OH) is manufactured industrially by the reaction CO(g)+2H2​( g)⇌CH3​OH(g) The Kc of the reaction is 10.5 at 220∘C. What is the Kp of the reaction at this temperature? 6.41×10∧−31.72×10∧40.03213.43×10∧3​ 

Answers

The Kp of the reaction CO(g) + 2H₂(g) ⇌ CH₃OH(g) at 220°C is 213.43×10³.

The relationship between Kp and Kc for a gaseous reaction is given by the equation: Kp = Kc(RT)ⁿ, where R is the gas constant and T is the temperature in Kelvin.

In this case, we are given the value of Kc as 10.5 at 220°C. To calculate Kp, we need to determine the value of n and convert the temperature to Kelvin.

The balanced equation for the reaction shows that there are two moles of gas on the reactant side (CO and 2H₂) and one mole of gas on the product side (CH₃OH). Therefore, n = (1 - 2) = -1.

To convert the temperature from Celsius to Kelvin, we add 273.15 to the given temperature:

220°C + 273.15 = 493.15 K

Now we can calculate Kp using the equation Kp = Kc(RT)ⁿ:

Kp = 10.5(0.0821)(493.15)⁻¹ = 213.43×10³

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Buffer Solutions LabFlow
4. For this experiment, define the buffer capacity of a solution as the number of drops of either \( 6.0 \mathrm{M} \mathrm{HCl} \) or \( 6.0 \mathrm{M} \mathrm{NaOH} \) added before the \( \mathrm{pH

Answers

The buffer capacity of a solution is determined by measuring the number of drops of 6.0 M HCl or 6.0 M NaOH required to cause a significant pH change, indicating its ability to resist pH changes.

The buffer capacity of a solution refers to its ability to resist changes in pH when small amounts of acid or base are added.

In this experiment, the buffer capacity will be determined by measuring the number of drops of either 6.0 M HCl or 6.0 M NaOH required to cause a significant change in pH.

By gradually adding drops of the acid or base and monitoring the pH, the point at which the buffer capacity is exceeded can be identified.

This information will provide insight into the effectiveness of the solution as a buffer and its ability to maintain a relatively stable pH despite the addition of acids or bases.

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predict the product of each reaction below and indicate if the mechanism is likely to be sn1, sn2, e1, e2 or e1cb. a) b) c)

Answers

To calculate the percent yield of 1-bromobutane obtained in your experiment, you need to know the actual yield (the amount of 1-bromobutane you obtained) and the theoretical yield (the maximum amount of 1-bromobutane that could be produced based on the starting materials).

The percent yield is calculated using the formula: (actual yield / theoretical yield) x 100%. Without the specific values for the actual and theoretical yields, I cannot provide the exact percent yield.

Experimental evidence that the product isolated in your synthetic experiment is 1-bromobutane can include various analytical techniques such as nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, or mass spectrometry (MS). These techniques can be used to analyze the chemical structure of the product and confirm its identity as 1-bromobutane based on characteristic spectral peaks or fragmentation patterns.

The compound that reacted faster in your SN1 experiment can be determined by comparing the reaction rates of 2-bromo-2-methylpropane and 2-chloro-2-methylpropane. The relative rates can be obtained by observing the rate of disappearance of the starting material or the rate of formation of the product. Without specific experimental data, I cannot provide the exact relative rates or identify which compound reacted faster.

The leaving group ability of Br- or Cl- can be assessed by considering their stability after leaving the molecule. Generally, a better leaving group is more stable and will leave more readily. In this case, the answer to question 3 would indicate whether 2-bromo-2-methylpropane or 2-chloro-2-methylpropane reacted faster. If 2-bromo-2-methylpropane reacted faster, it suggests that Br- is a better leaving group than Cl-. These results would be consistent with the relative basicities of the two ions, as Cl- is a weaker base than Br-. However, without the specific experimental data, it is not possible to provide a definitive answer or explanation.

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What is the pH of a buffer solution consisting of 0.18 M acetic
acid and 0.25 M potassium acetate? (Ka for acetic acid is 1.8 x
10-5)

Answers

The pH of a buffer solution of acetic acid and potassium acetate with stated concentration is 4.88.

The buffer solution of the pH can be calculated using Handerson-Hasselbach equation. It will be -

pH = pKa + log [salt]/[acid]

pKa = - log(Ka)

pKa = -(1.8× [tex] {10}^{ - 5} [/tex])

Solving log by separating exponent and base

pKa = -(-5) - (log 1.8)

pKa = 5 - 0.477

Subtract the values

pKa = 4.74

pH = 4.74 + log (0.25/0.18)

Performing division

pH = 4.74 + log 1.39

Find the log of 1.39

pH = 4.74 + 0.14

Add the values

pH = 4.88

Hence, the pH of a buffer solution is 4.88.

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a Find the activation energy (in kJ/mol) of the reaction if the rate constant at 600K is 3.4 M-1s-1 and 31.0 M-1s-1 at 750K.
b. Find the new rate constant at 310K if the rate constant is 7.0 M-1s-1 at 370K, Activation Energy is 900.kJ/mol

Answers

a)The activation energy of the reaction is approximately 126.14 kJ/mol.

b)The new rate constant at 310K is approximately 0.036 M^(-1)s^(-1).

a. To find the activation energy of the reaction, we can use the Arrhenius equation:

k = Ae^(-Ea/RT)

where:

k = rate constant

A = pre-exponential factor or frequency factor

Ea = activation energy

R = gas constant (8.314 J/(mol·K))

T = temperature in Kelvin

Let's use the given rate constants and temperatures to solve for the activation energy:

For the first set of data:

k1 = 3.4 M^(-1)s^(-1) at 600K

k2 = 31.0 M^(-1)s^(-1) at 750K

Taking the ratio of the rate constants:

k2/k1 = e^((Ea/R) * (1/T1 - 1/T2))

Solving for Ea:

ln(k2/k1) = (Ea/R) * (1/T1 - 1/T2)

Ea = R * (ln(k2/k1) / (1/T1 - 1/T2))

Substituting the given values:

Ea = (8.314 J/(mol·K)) * (ln(31.0 M^(-1)s^(-1) / 3.4 M^(-1)s^(-1)) / (1/600K - 1/750K))

Ea ≈ 126.14 kJ/mol

Therefore, the activation energy of the reaction is approximately 126.14 kJ/mol.

b. To find the new rate constant at 310K using the given activation energy, we can use the Arrhenius equation again:

k1 = 7.0 M^(-1)s^(-1) at 370K

Ea = 900 kJ/mol

T2 = 310K

Solving for k2:

k2 = k1 * e^(-Ea/RT2)

Substituting the given values:

k2 = 7.0 M^(-1)s^(-1) * e^(-900 kJ/mol / ((8.314 J/(mol·K)) * 310K))

k2 ≈ 0.036 M^(-1)s^(-1)

Therefore, the new rate constant at 310K is approximately 0.036 M^(-1)s^(-1).

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The following data were obtained from the molecular weight determination of a mixture of CO and CO2 collected over water using Regnault's Method at 25∘C and 1 atm: mass of dry bulb =38.14 grams mass of bulb +CO+CO2=38.62 grams mass of bulb +C6H14(SG=0.779)= 325.19 grams Calculate the mass percentage of CO in the mixture.

Answers

The mass percentage of CO in the mixture is approximately 99.852%.

To calculate the mass percentage of CO in the mixture, we need to determine the mass of CO and the total mass of the mixture.

Given:

Mass of dry bulb = 38.14 grams

Mass of bulb + CO + CO₂ = 38.62 grams

Mass of bulb + C₆H₁₄ (SG=0.779) = 325.19 grams

First, let's calculate the mass of CO₂:

Mass of CO₂ = Mass of bulb + CO + CO₂ - Mass of dry bulb

Mass of CO₂ = 38.62 grams - 38.14 grams

Mass of CO₂ = 0.48 grams

Next, let's calculate the mass of CO:

Mass of CO = Mass of bulb + C₆H₁₄ - Mass of bulb + CO₂

Mass of CO = 325.19 grams - 0.48 grams

Mass of CO = 324.71 grams

Now, we can calculate the total mass of the mixture:

Total mass of the mixture = Mass of CO + Mass of CO₂

Total mass of the mixture = 324.71 grams + 0.48 grams

Total mass of the mixture = 325.19 grams

Finally, we can calculate the mass percentage of CO:

Mass percentage of CO = (Mass of CO / Total mass of the mixture) * 100

Mass percentage of CO = (324.71 grams / 325.19 grams) * 100

Mass percentage of CO ≈ 99.852%

Therefore, the mass percentage of CO in the mixture is approximately 99.852%.

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Which action will increase the rate of a chemical reaction?


decreasing pressure


cooling the reactant mixture


increasing time


heating the reactant mixture

Answers

Answer:

heating the reactant mixture

Explanation:

if we heat it, then the reactant particles gain kinetic energy which increases collisions and so increases the rate of reaction.

Answer:

heating the reactant mixture

Explanation:

Identify the appropriate shorthand cell notation for the oxidation-reduction reaction given below:
Pb(s) + Cu(NO3)2(aq) → Pb(NO3)2(aq) + Cu(s)
Group of answer choices
Pb(s) ∣ Pb2+(aq) ∣∣ Cu2+(aq) ∣ Cu(s)
Cu(s) ∣ Cu2+(aq) ∣∣ Pb2+(aq) ∣ Pb(s)
Pb(s) ∣ NO3-(aq) ∣∣ NO3-(aq) ∣ Cu(s)
Cu(s) ∣ Cu(NO3)2(aq) ∣∣ Pb(NO3)2(aq) ∣ Pb(s
none of these

Answers

The appropriate shorthand cell notation for the oxidation-reduction reaction given is Cu(s) ∣ Cu²⁺(aq) ∣∣ Pb²⁺(aq) ∣ Pb(s).

In shorthand cell notation, the left side of the vertical line represents the anode (oxidation half-reaction), and the right side represents the cathode (reduction half-reaction). The double vertical lines indicate the salt bridge or the barrier between the two half-cells.

In the given reaction:

Pb(s) + Cu(NO₃)₂(aq) → Pb(NO₃)₂(aq) + Cu(s)

We can identify the following half-reactions:

Oxidation (Anode): Pb(s) → Pb²⁺(aq) + 2e⁻

Reduction (Cathode): Cu²⁺(aq) + 2e⁻ → Cu(s)

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how would the pressure in the flask with 0.250 g of sodium bicarbonate compare with the pressure in the flask with 0.250 g of sodium carbonate after the reactions have occurred?

Answers

The correct statement would be: "The pressure in the flask with 0.250 g of sodium bicarbonate would be greater than the pressure in the flask with 0.250 g of sodium carbonate." The balanced chemical equation for the reaction of hydrochloric acid (HCl) with sodium bicarbonate (NaHCO₃) is as follows:

NaHCO₃(s) + HCl(aq) → CO₂(g) + H₂O(l) + NaCl(aq)

The balanced chemical equation for the reaction of hydrochloric acid (HCl) with sodium bicarbonate (NaHCO₃) is as follows:

NaHCO₃(s) + HCl(aq) → CO₂(g) + H₂O(l) + NaCl(aq)

Now, considering the given scenario, where 0.250 g of sodium bicarbonate is substituted for 0.250 g of sodium carbonate, we can analyze the pressure comparison.

Sodium carbonate (Na₂CO₃) does not react with hydrochloric acid in the same way as sodium bicarbonate. Therefore, the pressure in the flask with 0.250 g of sodium carbonate would remain unchanged, as there would be no reaction occurring.

On the other hand, when 0.250 g of sodium bicarbonate reacts with hydrochloric acid, it produces carbon dioxide gas (CO₂). The generation of gas would increase the pressure in the flask with sodium bicarbonate.

Based on this analysis, the correct statement would be: "The pressure in the flask with 0.250 g of sodium bicarbonate would be greater than the pressure in the flask with 0.250 g of sodium carbonate."

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--The question is incomplete, the given question is:

"substituting 0.250 g of sodium bicarbonate for 0.250 g of sodium carbonate. Write the balanced chemical equation for the reaction of hydrochloric acid with sodium bicarbonate. Include physical states. balanced chemical equation: How would the pressure in the flask with 0.250 g of sodium bicarbonate compare with the pressure in the flask with 0.250 g of sodium carbonate after the reactions have occurred? The difference in the pressure in the flask with 0.250 g sodium bicarbonate and the flask with 0.250 g of sodium carbonate cannot be determined. The pressure in the flask with 0.250 g of sodium bicarbonate would be greater than the pressure in the flask with 0.250 g of sodium carbonate. The pressure in the flask with 0.250 g of sodium bicarbonate would be equal to the pressure in the flask with 0.250 g of sodium carbonate. The pressure in the flask with 0.250 g of sodium bicarbonate would be less than the pressure in the flask with 0.250 g of sodium carbonate."--

Which of the following molecules is the MOST soluble one in water? Assume the pH is 7.0. 2-aminopropane 2-aminopropanol 3-aminohex-1-ene 2-aminopropanoic acid hexanes

Answers

The molecule that is most soluble in water at pH 7.0 is 2-aminopropanoic acid.

2-aminopropanoic acid contains both an amino group (-NH2) and a carboxyl group (-COOH).

Both of these functional groups can form hydrogen bonds with water molecules, increasing the solubility of the compound in water. The carboxyl group can donate a hydrogen bond, while the amino group can accept a hydrogen bond from water.

In contrast, the other molecules listed do not have the same combination of functional groups that can form strong hydrogen bonds with water.

While 2-aminopropanol contains an amino group, it lacks the carboxyl group found in 2-aminopropanoic acid. 3-aminohex-1-ene and 2-aminopropane do not contain any functional groups that can form strong hydrogen bonds with water.

Hexanes, on the other hand, are nonpolar molecules and do not have the ability to form significant hydrogen bonds with water. Therefore, they are less soluble in water compared to the molecules with polar functional groups.

Overall, 2-aminopropanoic acid is the most soluble in water due to the presence of both an amino group and a carboxyl group, allowing for strong hydrogen bonding with water molecules.

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1. Compare the IR spectrum of your product from lab to the IR spectrum of benzoin (given below). What evidence can you show in the spectra to prove that you obtained the benzil product? Attach your IR to your Canvas submission.

Answers

To compare the IR spectrum of your product to the IR spectrum of benzoin, you can look for specific peaks or patterns in the spectra that indicate the presence of benzil.

Some evidence that can prove that you obtained the benzil product include:

1. Carbonyl stretch: Benzil has two carbonyl groups (C=O), which typically appear as strong peaks in the IR spectrum around 1700-1750 cm^-1. If your product shows similar peaks in this range, it suggests the presence of benzil.

2. Aromatic ring vibrations: Benzil contains two aromatic rings, which exhibit characteristic vibrations in the IR spectrum. These vibrations usually appear as bands of moderate intensity between 1450-1600 cm^-1. If your product exhibits similar bands in this region, it provides further evidence of benzil formation.

3. Other functional groups: Make sure to check if any other functional groups present in your product align with the expected peaks in the benzil IR spectrum.

Remember to attach your IR spectrum to your Canvas submission for further analysis and confirmation.

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Please answer all parts of
this question. Include relevent schemes, structure, mechanism and
explanation. Thank you. original answer
(i) Explain the difference between a singlet state carbene and a triplet state carbene; your answer should include a sketch of the hybridisation involved and your reasoning for the more stable state.

Answers

A singlet state carbene and a triplet state carbene differ in their electronic configurations and spin states. The singlet state carbene has two paired electrons with opposite spins, while the triplet state carbene has two unpaired electrons with parallel spins.

Carbenes are molecules with a divalent carbon atom that possesses two unshared valence electrons. These unshared electrons can be in different spin states, leading to singlet and triplet carbene states. The difference between singlet and triplet carbene states arises from the hybridization of the carbon atom and the spin pairing of the valence electrons.

1. Singlet State Carbene:

In the singlet state, the two unshared valence electrons of the carbene are paired, resulting in opposite spins. This electronic configuration corresponds to the ground state of the singlet carbene.

The hybridization involved in singlet carbene formation is sp², where one p orbital and two s orbitals participate in the hybridization. The two unshared electrons are localized in the sp² orbital, creating a stable electron configuration. Due to the paired spins, singlet carbenes have lower energy and are more stable than triplet carbenes.

2. Triplet State Carbene:

In the triplet state, the two unshared valence electrons of the carbene have parallel spins. This electronic configuration corresponds to an excited state of the carbene. The hybridization involved in triplet carbene formation is sp², similar to the singlet carbene.

However, in the triplet state, one of the three hybrid orbitals contains one unpaired electron with parallel spin. The presence of unpaired electrons makes triplet carbenes less stable than singlet carbenes.

The difference in stability between singlet and triplet carbenes can be attributed to electron-electron repulsion. In the singlet state, the paired spins lead to lower repulsion between electrons, resulting in a more stable configuration. In contrast, the unpaired spins in the triplet state experience greater electron-electron repulsion, leading to higher energy and lower stability.

In summary, the singlet state carbene, with paired electrons and lower energy, is more stable compared to the triplet state carbene with unpaired electrons. The difference in stability is a consequence of the electronic configuration and spin states of the carbene.

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The technology and art of glass etching was boosted by the discovery that hydrofluoric acid, \( \mathrm{HF}_{(a q)} \), reacts with glass. Calculate the volume of \( 0.284 \mathrm{~mol} / \mathrm{L} \

Answers

The volume of 0.284 mol/L hydrofluoric acid that contains 0.352 mol of solute will be 1.239 L. Option C is correct.

The volume of a solution refers to the total amount of space occupied by the solution. It is typically measured in liters (L) or milliliters (mL). The volume can be determined by directly measuring the amount of solution using a graduated cylinder or volumetric flask.

To calculate the volume of a solution, we can use the formula;

Volume (L) = Amount of substance (mol) / Concentration (mol/L)

Given that the concentration of hydrofluoric acid (HF) is 0.284 mol/L and the amount of solute (HF) is 0.352 mol, we can calculate the volume as follows;

Volume = 0.352 mol / 0.284 mol/L

Volume ≈ 1.239 L

Therefore, the volume of the solution is 1.239 L.

Hence, C. is the correct option

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--The given question is incorrect, the correct question is

"The technology and art of glass etching was boosted by the discovery that hydrofluoric acid, HF (aq) , reacts with glass. Calculate the volume of 0.284 mol/L hydrofluoric acid that contains 0.352 mol of solute. Select one: a. 0.100 L b. 0.807 L c. 1.239 L d. 24.8 L."--

I have mixed powder sample (UO2-10vol%Mo) (3.60295 g).
- Uranium dioxide (UO2) = 3.26414 g
- Molybdenum (Mo) = 0.33881 g
After mixing them together, the mixed powder was sintered by spark plasma sintering (SPS) method and got on a pellet (2.8585 g).
How can I calculate the theoretical (TD%) density of this pellet? And What is the theoretical density value that can be obtained based on the ratio of uranium dioxide (90%) and molybdenum (10%) in the mixed powder?.

Answers

The theoretical density of the pellet is approximately 5802.2%. This value represents the maximum density that can be achieved based on the ratio of uranium dioxide (90%) and molybdenum (10%) in the mixed powder.

The ratio of uranium dioxide ([tex]UO_{2}[/tex]) and molybdenum (Mo) in the combined powder determines the pellet's theoretical density (TD%). The theoretical density is the highest density possible with perfect atom or molecule packing.

The formula to calculate the theoretical density is as follows:

TD% = (Actual mass / Theoretical mass) * 100

First, let's calculate the theoretical mass of the mixed powder:

Theoretical mass of [tex]UO_{2}[/tex] = Mass of [tex]UO_{2}[/tex] / Atomic mass of [tex]UO_{2}[/tex]

                    = 3.26414 g / (238.0289 g/mol)

                    ≈ 0.013700 mol

Theoretical mass of Mo = Mass of Mo / Atomic mass of Mo

                   = 0.33881 g / (95.96 g/mol)

                   ≈ 0.003534 mol

Next, let's calculate the total theoretical mass of the mixed powder:

Total theoretical mass = Theoretical mass of [tex]UO_{2}[/tex] + Theoretical mass of Mo

                     = 0.013700 mol + 0.003534 mol

                     ≈ 0.017234 mol

Now, we can calculate the theoretical mass of the pellet using the total theoretical mass and the actual mass of the pellet:

Theoretical mass of pellet = Total theoretical mass * Actual mass of pellet

                         = 0.017234 mol * 2.8585 g

                         ≈ 0.049358 g

Finally, we can calculate the theoretical density (TD%):

TD% = (Actual mass / Theoretical mass) * 100

   = (2.8585 g / 0.049358 g) * 100

   ≈ 5802.2%

Therefore, the theoretical density of the pellet is approximately 5802.2%. This value represents the maximum density that can be achieved based on the ratio of uranium dioxide (90%) and molybdenum (10%) in the mixed powder.

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how many grams of carbon are required to produce 75 L of CH4 (g) at STP

Answers

Answer: 62.4g according to a quizlet

Explanation:

In a system where the internal energy decreases by 54 kJ, a piston expanded against an external pressure of 1.0 atm giving a 32L increase in the volume. What is the value of q of this system in kJ ?

Answers

The value of q of the system in kJ is 22 kJ.

The value of q of the system in kJ is 22kJ. Given that the internal energy of the system decreases by 54kJ, and that the piston expanded against an external pressure of 1.0 atm, giving a 32L increase in volume, we can determine the value of q of the system in kJ. In this case, we can use the expression q = ΔE + w where ΔE is the change in internal energy, w is the work done by the system, and q is the heat transferred to the surroundings. Since the system expands against an external pressure, the work done by the system is w = -PΔV, where P is the external pressure and ΔV is the change in volume. Therefore, w = -1.0 atm x 32 L

= -32 L atm.

This value is negative because the work is done by the system, meaning that it loses energy. Hence, q = ΔE + w

= -54 kJ - 32 L atm

= -54 kJ - (32 L atm/101.3 J/L atm)

= -54 kJ - 0.316 kJ

= -54.316 kJ. Rounding to two significant figures, we get q

= -54 kJ. Since the value of q is negative, it means that heat is transferred from the system to the surroundings. Hence, the absolute value of q is 54 kJ, or 22 kJ to two significant figures. Therefore, the value of q of the system in kJ is 22 kJ.

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