Answer: The question wants you to determine the energy that the incoming photon must have in order to allow the electron that absorbs it to jump from
n
i
=
2
to
n
f
=
6
.
A good starting point here will be to calculate the energy of the photon emitted when the electron falls from
n
i
=
6
to
n
f
=
2
by using the Rydberg equation.
1
λ
=
R
⋅
(
1
n
2
f
−
1
n
2
i
)
Here
λ
si the wavelength of the emittted photon
R
is the Rydberg constant, equal to
1.097
⋅
10
7
m
−
1
Plug in your values to find
1
λ
=
1.097
⋅
10
7
.
m
−
1
⋅
(
1
2
2
−
1
6
2
)
1
λ
=
2.4378
⋅
10
6
.
m
−
1
This means that you have
λ
=
4.10
⋅
10
−
7
.
m
So, you know that when an electron falls from
n
i
=
6
to
n
f
=
2
, a photon of wavelength
410 nm
is emitted. This implies that in order for the electron to jump from
n
i
=
2
to
n
f
=
6
, it must absorb a photon of the same wavelength.
To find the energy of this photon, you can use the Planck - Einstein relation, which looks like this
E
=
h
⋅
c
λ
Here
E
is the energy of the photon
h
is Planck's constant, equal to
6.626
⋅
10
−
34
.
J s
c
is the speed of light in a vacuum, usually given as
3
⋅
10
8
.
m s
−
1
As you can see, this equation shows you that the energy of the photon is inversely proportional to its wavelength, which, of course, implies that it is directly proportional to its frequency.
Plug in the wavelength of the photon in meters to find its energy
E
=
6.626
⋅
10
−
34
.
J
s
⋅
3
⋅
10
8
m
s
−
1
4.10
⋅
10
−
7
m
E
=
4.85
⋅
10
−
19
.
J
−−−−−−−−−−−−−−−−−
I'll leave the answer rounded to three sig figs.
So, you can say that in a hydrogen atom, an electron located on
n
i
=
2
that absorbs a photon of energy
4.85
⋅
10
−
19
J
can make the jump to
n
f
=
6
.
Explanation:
The rate constant of an SN1 reaction depends on the nucleophile b. The rate constant of an SN2 reaction does not depend on the nucleophile c. SN1 reactions proceed via carbocation intermediates d. The SN2 mechanism does not involve an intermediate
Answer:
The rate constant of an SN1 reaction depends on the nucleophile
The rate constant of an SN2 reaction does not depend on the nucleophile
Explanation:
Let us recall that in an SN1 reaction, the rate determining step involves only the alkyl halide substrate and not the nucleophile. Hence;
Rate = k[RX]
Therefore;
k= Rate/[RX]
For an SN2 reaction, the rate determining step involves both the nucleophile and the alkyl halide substrate.
Hence;
Rate = k[Nu-] [RX]
k= Rate/[Nu-] [RX]
Note that;
[Nu-] = concentration of the nucleophile
[RX] =concentration of alkyl halide substrate
k= rate constant
We can see from the above derivations that;
1) The rate constant of an SN1 reaction does not depend on the nucleophile
2) The rate constant of an SN2 reaction depends on the nucleophile
In an ELISA, the compound 4-chloro-1-naphthol is used because:_______
a. it turns color in the presence of an enzyme that is bound to the secondary antibody
b. it helps the primary antibody bind to the protein
c. it helps the secondary antibody to bind to the protein
d. all of the choices
Answer:
a. It turns color in the presence of an enzyme that us bound to the secondary antibody.
Explanation:
The compound chloronapthenel is used in the reaction because it changes the color in the presence of an enzyme. It is strong organic compound which is used in biochemical processes.
A bond dissociation energy is A) The energy required to remove an electron from an atom. B) The energy released when an ionic compound dissociates in water. C) The energy required to break a covalent bond. D) The energy produced in a chemical reaction that breaks chemical bonds.
Answer:
The energy required to break a covalent bond
Explanation:
When a chemical bond is formed, energy is released. When a chemical bond is broken, energy is absorbed.
We define the bond dissociation energy as the energy required to break a covalent bond. The process of covalent bond cleavage is endothermic hence energy is absorbed for the process to occur.
What is the pH of a solution with an [H+] of (a) 5.4 x 10-10, (b) 4.3 x 10-5, (c) 5.4 x 10-7?
Answer:
a. 9.2
b. 4.4
c. 6.3
Explanation:
In order to calculate the pH of each solution, we will use the definition of pH.
pH = -log [H⁺]
(a) [H⁺] = 5.4 × 10⁻¹⁰ M
pH = -log [H⁺] = -log 5.4 × 10⁻¹⁰ = 9.2
Since pH > 7, the solution is basic.
(b) [H⁺] = 4.3 × 10⁻⁵ M
pH = -log [H⁺] = -log 4.3 × 10⁻⁵ = 4.4
Since pH < 7, the solution is acid.
(c) [H⁺] = 5.4 × 10⁻⁷ M
pH = -log [H⁺] = -log 5.4 × 10⁻⁷ = 6.3
Since pH < 7, the solution is acid.
What is the trend in electropositivity in group 1 elements?
Answer:
Electro positivity increases down the group
How many nitrate ions are present in the following aqueous solution?
5.08 L of a solution containing 2.68 x 1021 formula units of lithium nitrate per liter.
When you have the number, determine its log (base 10) and enter that value with 3 decimal places
Answer:
22.1
Explanation:
Step 1: Calculate the number of formula units of lithium nitrate
A 5.08 L solution contains 2.68 × 10²¹ formula units per liter.
5.08 L × 2.68 × 10²¹ formula units/1 L = 1.36 × 10²² formula units
Step 2: Calculate the number of nitrate ions
Lithium nitrate dissociates completely in water according to the following equation.
LiNO₃(aq) ⇒ Li⁺(aq) + NO₃⁻(aq)
The molar ratio of LiNO₃ to NO₃⁻ is 1:1. The number of nitrate ions is 1/1 × 1.36 × 10²² = 1.36 × 10²².
Then,
log (1.36 × 10²²) = 22.1
The number of nitrate ions are present in the following aqueous solution is 13.6x10²¹, and log(base 10) value of this is 22.2.
What are strong electrolytes?
Those salts which are completely dissociate into their ions in the solution form will known as strong electrolyte.
Lithium nitrate is a strong electrolyte and it shows complete dissociation as:
LiNO₃ → Li⁺ + NO₃⁻
Given that,
1 liter of solution containing = 2.68 x 10²¹ formula unit
5.08 L of solution containing = 5.08 x 2.68 x 10²¹ = 13.6x10²¹ formula unit
So, number of nitrate ion in given solution = 13.6x10²¹ formula unit
Log(13.6x10²¹) = 22.1
Hence, required values are 13.6x10²¹ and 22.1.
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Because the double bond in an alkene is rigid, alkenes can exist as geometric isomers. To clarify geometric isomers, IUPAC uses cis- and trans- as part of a compound name. If the substituents around the double bond are on the same side of the double bond, this is called
cis, cis.
cis.
cis, trans.
trans.
Answer:
cis
Explanation:
Cis isomers are formed when the substituents on the carbons of the double bond are on the same side of the double bond, forming a U. Trans isomers have substituents on opposite sides of the double bond, forming a sideways Z.
Place the following elements in order of decreasing atomic size: lead, phosphorus, oxygen, cesium, barium, and silicon.
Rank from largest to smallest. To rank items as equivalent, overlap them.
Cs, O, P, Si, Ba, Pb
Answer:
Cs> Ba> Pb>Si> P>O
Explanation:
Recall that atomic size decreases across a period and increases down the group.
As we move from Cs to Ba, the atomic size decreases across the period. Lead is larger than silicon since atomic size increases down the group.
Between phosphorus and oxygen, phosphorus is larger than oxygen as you move across the period.
Which process refers to the dissociation of Naci into Na+ and Ci+?
Answer:
dissolution is the process
b. Sodium has an emission spectrum with two visible wavelengths, both very close to 590 nm. If you had a light source that contained a mixture of sodium and hydrogen, what color filter would you use to measure only the hydrogen spectrum
Answer:
Blue or Purple color filter
Explanation:
Given that Sodium has an emission spectrum with wavelength ≈ 590nm and for a wavelength of 590nm the color is yellow.
Hence To filter out the color ( yellow ) to enable the measurement of the Balmer series of hydrogen spectrum, we have to use a filter that possess the complementary color of yellow ( i.e. purple(RYB color model) or blue (RGB additive color model )
therefore color filter to be used = Blue or Purple
Predict whether solutions of each of the following salts will be acidic, basic, or neutral. Explain your reasoning for each by writing a balanced net ionic equation to describe the chemistry of each non-neutral salt in water:
a. NaCN
b. KNO3
c. NH4Cl
d. NaHCO3
e. Na3PO4.
Answer:
NaCN- basic salt
KNO3 - neutral salt
NH4Cl - acid salt
NaHCO3 - acid salt
Na3PO4 - acid salt
Explanation:
Salt hydrolysis a process by which salts react with water giving an acid and a base.
When we dissolve NaCN in water, we have;
NaCN + - ⇄ Na^+ + CN^-
KNO3 ------> K^+ + NO3^-
NH4Cl ------> NH4^+ + Cl^-
NaHCO3 -----> Na^+ + HCO3^-
Na3PO4 ----> 3Na^+ + PO4^3-
Note that if a salt is formed from a weak acid and a strong base, the salt will be a basic salt e.g NaCN formed from weak HCN and strong NaOH.
If a salt is formed from a strong acid and weak base, the salt will be acidic, e.gNH4Cl formed from weak NH3 and strong HCl.
If a salt is formed from a strong acid and strong base, the salt will be neutral, e.g KNO3 formed from strong KOH and strong HNO3.
Balance the following equations Ag (s) + H₂ S(g) + 0₂ (g) → Ag₂ S(₅) + H₂0
Answer:
2Ag(s) + 2H²S(g) + O2(g) ➡️ Ag2S(s) + 2H2O(g)
Explanation:
Sorry for my typo. but you understand
Hydrogengasand oxygengas react to form water vapor. Suppose you have of and of in a reactor. Calculate the largest amount of that could be produced. Round your answer to the nearest .
The question is incomplete. The complete question is :
Hydrogen [tex](H_2)[/tex] gas and oxygen [tex](O_2)[/tex] gas react to form water vapor [tex](H_2O)[/tex]. Suppose you have 11.0 mol of [tex]H_2[/tex] and 13.0 mol of [tex]O_2[/tex] in a reactor. Calculate the largest amount of [tex]H_2O[/tex] that could be produced. Round your answer to the nearest 0.1 mol .
Solution :
The balanced reaction for reaction is :
[tex]$2H_2(g) \ \ \ \ + \ \ \ \ \ O_2(g)\ \ \ \rightarrow \ \ \ \ 2H_2O(g)$[/tex]
11.0 13.0
11/2 13/1 (dividing by the co-efficient)
6.5 mol 13 mol (minimum is limiting reagent as it is completely consumed during the reaction)
Therefore, [tex]H_2[/tex] is limiting reagent. It's stoichiometry decides the product formation amount from equation above it is clear that number of moles for [tex]H_2O[/tex] will be produced = number of moles of [tex]H_2[/tex]
= 11.0 mol
A sample of helium gas at a pressure of 0.778 atm and a temperature of 20.2 °C, occupies a volume of 574 mL. If the gas is allowed to expand at constant temperature until its pressure is 0.373 atm, the volume of the gas sample will be mL.
Answer:
I don't know ❤️
How many moles of Al are needed to react exactly with 10.00 moles of Fe2O3 according to the following
equation?
Fe2O3 + 2 Al → Al2O3 + 2Fe
A) 15.0 moles
1
B) 20.0 moles
C) 30.0 moles
D) 60.0 moles
E) 35.0 moles
Answer:
Answer is B) 20.0 moles
Explanation:
From the equation,
1 mole of Fe2O3 = 2 moles of Al
therefore 10.0 moles of Fe2O3 = 10×2
= 20.0 moles.
81.5 g of metal was heated from 11 degrees Celsius to 69 degrees Celsius. If 6739 joules of heat energy were used, what is the specific heat capacity of the metal?
Answer:
the metal become red hot
What particules make up the nucleus
Answer:
nucleus is a collection of particles called protons,which are positively charged..and neutrons which are electrically neutral..electrons which are negatively charged..and neutrons are in turn made up of particles called quarks ..
Explanation:
hope this helps u ...
Answer:
The Nucleus is made up of protons and neutrons.
Suppose a 250.mL flask is filled with 1.7mol of H2 and 0.90mol of I2. The following reaction becomes possible:
+H2gI2g 2HIg
The equilibrium constant K for this reaction is 5.51 at the temperature of the flask.
Calculate the equilibrium molarity of I2. Round your answer to two decimal places.
Explanation:
here's the answer. I just plug the expression into my calculator and find the intercept to avoid the quadratic formula
Based on the reaction below:
[tex]N_2 + 3H_2[/tex] ↔ [tex]2NH_3 + heat[/tex]
If we decrease the temperature, equilibrium will shift towards the...
Please explain!
N₂ + 3H₂ ⇄ 2NH₃ + heat
In the given equilibrium, we notice that the heat is on the right. which means that if the heat requirements don't meet, the reactants on the right will no longer react due to the lack of heat
but because the reactants on the left don't have such weaknesses, they will keep reacting hence producing more and more ammonia until a new equilibrium is reached
where there will be more ammonia and less nitrogen and hydrogen as compared to the equilibrium we had initially
Answer:
Explanation:
heat is given out as 1 of the products, along w/ NH3 in the forward reaction. so its an exothermic reaction
decreasing temperature favors exothermic reaction as more heat can be absorbed by the environment
so equilibrium will shift towards the products
Two hydrogen atoms interact to form a hydrogen molecule.
a. True
b. False
Answer:
a. True
Explanation:
An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such determines or defines the structure of a chemical element.
Generally, atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.
A chemical reaction can be defined as a chemical process which typically involves the transformation or rearrangement of the atomic, ionic or molecular structure of an element through the breakdown and formation of chemical bonds to produce a new compound or substance.
Hydrogen is the simplest chemical element that exists. The symbol for the chemical element hydrogen is "H" and it is a colourless, tasteless, odorless, and highly flammable gas.
It is a chemical element found in group (1) of the periodic table and as such it has one (1) electron in its outermost shell. Thus, hydrogen has an atomic number of one (1) and a single valence electron because it has only one (1) proton and one (1) electron in its nucleus.
In Stoichiometry, two hydrogen atoms interact to form a hydrogen molecule, with each atom having a single electron in the 1S orbital. These hydrogen atoms react with each other due to the presence of a balanced attractive and repulsive force, which produces a strong covalent bond (H-H) in the hydrogen molecule.
Energy is released in the form of heat when the electrons in the orbitals of the two (2) hydrogen atoms form a covalent bond (H-H); thus, it's an exothermic chemical reaction.
When would exposure to a potentially harmful substance most likely to damage many organs in a developing embryo?
Give me an atom with the following characteristics:
Lanthanide series
Boron
Chalogen
Alkaline Earth metal
Explanation:
Lanthanide series= E4
Boron=Si
Chalogen=O
Alkaline Earth metal =M9
Consider the chemical reaction: N2 3H2 yields 2NH3. If the concentration of the reactant H2 was increased from 1.0 x 10-2 M to 2.5 x 10-1 M, calculate the reaction quotient (Q) and determine which way the chemical system would shift by comparing the value of Q to K.
In this equilibrium, the chemical system will shift to the right in order to produce more NH₃.
The equilibrium constant of a reaction is defined as:
"The ratio between equilibrium concentrations of products powered to their reaction quotient and equilibrium concentration of reactants powered to thier reaction quotient".
The reaction quotient, Q, has the same algebraic expressions but use the actual concentrations of reactants.
To solve this question we need this additional information:
For this reaction, K = 6.0x10⁻² and the initial concentrations of the reactants are:
[N₂] = 4.0M; [NH₃] = 1.0x10⁻⁴M and [H₂] = 1.0x10⁻²M
Thus, for the reaction:
N₂ + 3H₂ ⇄ 2NH₃
The equilibrium constant, K, of this reaction, is defined as:
[tex]K = \frac{[NH_3]^2}{[H_2]^3[N_2]}[/tex]
Where [] are concentrations in equilibrium.
And Q, is:
[tex]Q = \frac{[NH_3]^2}{[H_2]^3[N_2]}[/tex]
Where actual concentrations are:
[NH₃] = 1.0x10⁻⁴M
[N₂] = 4.0M
[H₂] = 2.5x10⁻¹M
Replacing:
Q = 1.6x10⁻⁷
As Q < K,
The chemical system will shift to the right in order to produce more NH₃
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Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O. A 0.165-g sample is combusted to produce 0.166 g of water and 0.403 g of carbon dioxide. What is the empirical formula for valproic acid
Answer:
The empirical formula is C4H8O
Explanation:
Step 1: Data given
Valproic acid is composed of C, H, and O
Mass of the sample = 0.165 grams
Mass of water = 0.166 grams
Mass of CO2 = 0.403 grams
Molar mass of water ( H2O) = 18.02 g/mol
Molar mass of CO2 = 44.01 g/mol
Atomic mass of C = 12.01 g/mol
Atomic mass of O = 16.0 g/mol
Atomic mass H = 1.01 g/mol (H2 = 2.02 g/mol)
Step 2: The equation
CxHyOz + O2 → CO2 + H2O
Step 3: Calculate the number of carbon in the sample
The carbon comes from CO2
Mass C = (12.01 g/mol/44.01 g/mol) * 0.403 grams
Mass C = 0.110 grams
Step 4: Calculate mass of hydrogen in the sample
The hydrogen comes from H2O
Mass H = (2.02/18.02) * 0.166 grams
MAss H = 0.0186 grams
Step 5: Calculate mass of O
The mass of O in the sample = Mass of sample - mass of H - mass of C
The mass of O = 0.165 grams - 0.110 grams - 0.0186 grams
The mass of O = 0.0364 grams
Step 6: Calculate moles
Moles C = 0.110 grams / 12.01 g/mol = 0.00916 moles
Moles H = 0.0186 / 1.01 = 0.0184 moles
Moles O = 0.0364/16.0 = 0.00228 moles
Step 7: Calculate empirical formula
We divide by the smallest amount of moles
C: 0.00916/ 0.00228 = 4
H: 0.0184/0.00228 = 8
O: 0.00228/0.00228 = 1
The empirical formula is C4H8O
100 mL of 0.2 mol/L sodium carbonate solution and 200 mL of 0.1 mol/L calcium nitrate solution are mixed together. Calculate the mass of calcium carbonate that would precipitate and the concentration of the sodium nitrate solution that will be produced.
Answer:
Explanation:
Na2CO3+Ca(NO3)2=CaCO3+2NaNO3
nNa2CO3=0.02
nCa(NO3)2=0.02
mCaCO3=0.02*100=2 gram
nNaNo3=0.04
Cm=2/15
From the calculation, the mass of the product is 2 g.
What is a reaction?A chemical reaction occurs when two more substances are mixed together. In this case, the reaction is shown by; Ca(NO3)2 + Na2CO3 ----> CaCO3(s) + 2NaNO3.
Number of moles of Na2CO3 = 100/1000 L * 0.2 mol/L = 0.02 moles
Number of moles of Ca(NO3)2 = 200/1000 L * 0.1 mol/L = 0.02 moles
Since the reaction is equimolar, amount of the product = 0.02 moles * 100 g/mol = 2 g
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If the Ksp of NaCl is experimentally determined to be 43.9, then what is the concentration of Na (in M) when it begins to crystallize out of solution
Answer:
6.63 M
Explanation:
NaCl(s) ---> Na^+(aq) + Cl^-(aq)
Given that [Na^+] = [Cl^-] = s
Where s= concentration of the both ions
Ksp = s^2
s= √Ksp
s= √43.9
s= 6.63 M
The concentration of Na (in M) obtained when it begins to crystallize out of solution is 6.63 M
What is solubility of product?The solubility of product (Ksp) is defined as the concentration of products raised to their coefficient coefficients. This is illustrated below:
mX <=> nY + eZ
Ksp = [Y]^n × [Z]^e
Dissociation equationNaCl(aq) → Na⁺(aq) + Cl¯(aq)
Let the concentration of Na⁺ be yLet the concentration of Cl¯ be yHow to determine the concentration of Na⁺ Solubility of product (Ksp) = 43.9Concentration of Cl¯ = yConcentration of Na⁺ = y =?Ksp = [Na⁺] × [Cl¯]
43.9 = y × y
43.9 = y²
Take the square root of both side
y = √43.9
y = 6.63 M
Thus, the concentration of Na⁺ is 6.63 M
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If 650. grams of C6H12O6 (FW 180.16) reacts with 650. grams of O2 (FW 32.00) in cellular respiration: C6H12O6 6 O2 --> 6 CO2 6 H2O Which is the limiting reactant
Answer:
O2 is limiting reactant
Explanation:
To find the limiting reactant we need to convert the mass of each reactant to the moles using the formula weight. And, as 1 mole of C6H12O6 reacts with 6 moles of O2, we can know wich reactant will be over first (Limiting reactant) as follows:
Moles C6H12O6:
650g * (1mol/180.16g) = 3.608 moles C6H12O6
Moles O2:
650g * (1mol/32g) = 20.31 moles O2
Now, for a complete reaction of 3.608 moles of C6H12O6 are required:
3.608 moles C6H12O6 * (6mol O2 / 1mol C6H12O6) = 21.65 moles O2
As there are just 20.31 moles of O2,
O2 is limiting reactantKarl-Anthony is trying to plate gold onto his silver ring. He constructs an electrolytic cell using his ring as one of the electrodes. He runs this cell for 94.3 minutes at 205.3 mA. How many moles of electrons were transferred in this process
Answer:
0.012 moles of electrons were transferred
Explanation:
We can find the number of electrons transferred from the time in seconds and the current in Amperes using the equation:
n = I*t / F
Where n are moles of electrons transferred
I is current in Amperes = 0.2053A
t is time in seconds:
94.3min*(60s/1min) = 5658s
F is faraday constant 96485A*s/mol
Replacing:
n = 0.2053A*5658s / 96485A*s/mol
n = 0.012 moles of electrons were transferred
Moles are the mass per unit molar mass of compound. The number of moles of electrons that are transferred is 0.012 moles.
What is an electrolytic cell?An electrolytic cell is a type of electrochemical cell that uses electrical energy from external sources to conduct the chemical energy in a cell.
The moles transferred in electrolytic cells are measured as:
[tex]\rm n = \rm \dfrac{I\times t}{F}[/tex]
Given,
Current (I) in amperes = 0.2053 A
Time (t) in seconds = 5658 sec
Faraday constant (F) = 96485 A -s/mol
Substituting values in the equation above moles (n) can be calculated as:
[tex]\begin{aligned} \rm n &= \dfrac{ 0.2053 \times 5658 }{96485}\\\\&= 0.012 \;\rm mol\end{aligned}[/tex]
Therefore, 0.012 moles are transferred in this process.
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Complete (predict the products, write correct formulas) and balance the following reaction:
Gaseous hydrochloric acid reacts with solid calcium hydroxide. Include states of matter and use subscripts as needed to receive full credit for a correct answer.
Explanation:
since hydrochloric acid is an acid and calcium hydroxide is a base, we know that this is an acid base reaction. The ions will then dissociatiate and bond with one another.
Two chemicals A and B are combined to form a chemical C. The rate, or velocity, of the reaction is proportional to the product of the instantaneous amounts of A and B not converted to chemical C. Initially, there are 100 grams of A and 50 grams of B, and for each gram of B, 2 grams of A is used. It is observed that 25 grams of C is formed in 9 minutes. How much is formed in 36 minutes
Answer:
In 36 minutes, 100 grams of Chemical C is formed.
Explanation:
Combination of chemicals A and B = chemical C
Chemical A available = 100 grams
Chemical B available = 50 grams
Proportion of A mixed with C = A2
Proportion of B mixed with C = B1
Therefore, Chemical C = A2 + B1
If 25 grams of C is formed in 9 minutes
In one minute 25/9 grams of C will be formed
Therefore, in 36 minutes, 25/9 * 36 = 100 grams
