Answer:
The right answer is "105.17 ppb".
Explanation:
According to the question,
The amount of [tex]Pb^{2+}[/tex] in ppb will be:
= [tex]0.5076\times 10^{-6}\times 207.2\times 106[/tex]
= [tex]105.17 \ ppb[/tex]
Thus, the amount of [tex]Pb^{2+}[/tex] is above action limit.
most naturally occurring oxygen is
12 grams of carbon is burnt with a certain amount of air containing 36 grams of oxygen. The product contains 24 grams of Co, and 4 grams of CO. Calculate the percentage of excess oxygen.
Answer:
C
Oxygen gas is limiting.
C(s) + O
2
→CO
2
(g)
No. of moles of carbon =
12
36
=3 moles
No. of moles of oxygen =
32
32
=1 moles
So, 2 moles of carbon is left and oxygen will be completed.
So, O
2
is limiting reagent.
Answer:
14.5
Explanation:
not sure how I got it but I hope this helped!
The reaction A + B <-------> C + D has been studied at five widely different temperature and the equilibrium tabulated.
Equilibrium constant K (at varies temperatures)
K at T1 1 x 10^-2
K at T2 2.25
K at T3 1.0
K at T4 81
K at T5 4 x 10^1
Which temperature is the products favored?
If K is greater than 1, then products are favored
The standard free energy that is required for the sodium-potassium ATPase to pump two K ions into the cell and three Na ions is 43.8 kJ/mol but the standard free energy change of hydrolysis of ATP is only -32 kJ/mol. This apparent imbalance of free energy can be accounted for because ________.
Answer:
Explanation:
This apparent disparity of the free energy can be taken into account because:
the free energy produced by the hydrolysis of one ATP is adequate enough under psychological circumstances.
The Na-K ATPase aids the pumping of Na+ ions out of the cell and K+ ions into the cell. These actions occurring against their potential(concentration) gradients, which may be produced by hydrolyzing one ATP molecule.
Suppose that you add 24.3 g of an unknown molecular compound to 0.250 kg of benzene, which has a K f of 5.12 oC/m. With the added solute, you find that there is a freezing point depression of 3.14 oC compared to pure benzene. What is the molar mass (in g/mol) of the unknown compound
Solution :
We know that :
[tex]$\Delta T_f = k_f.m$[/tex] and [tex]$m=\frac{w_2}{m_2 \times w_1}$[/tex]
Then, [tex]$\Delta T_f = k_f.\frac{w_2}{m_2.w_1}$[/tex] ..................(1)
Where,
[tex]w_1[/tex] = amount of solvent (in kg)
[tex]w_2[/tex] = amount of solute (in kg)
[tex]m_2[/tex] = molar mass of solute (g/mole)
[tex]m[/tex] = molality of solution (mole/kg)
Given :
[tex]\Delta T_f[/tex] = [tex]3.14\ ^\circ C[/tex], [tex]k_f= 5.12\ ^\circ C/m[/tex]
[tex]=5.12 \ ^\circ C/mole/kg[/tex]
[tex]=5.12 \ ^\circ C \ kg/mole[/tex]
[tex]w_1[/tex] = 0.250 kg, [tex]w_2[/tex] = 24.3 g
Then putting this values in the equation is (1),
[tex]$3.14 = \frac{5.12 \times 24.3}{m_2 \times 0.250}$[/tex]
[tex]$m_2 = \frac{5.12 \times 24.3}{3.14 \times 0.250}$[/tex]
[tex]m_2= 158.49[/tex] g/mole
So, the molar mass of the unknown compound is 158.49 g/mole.
Give the IUPAC and common name
Answer:
IUPAC Name:
N-ethyl-N-methylaniline
Common Name:
Benzenamine
A wavelength of 489.2 nm is observed in a hydrogen spectrum for a transition that ends in the nf level of the Balmer series. What was ni for the initial level of the electron
Answer:
[tex]n_1=4[/tex]
Explanation:
From the question we are told that:
Wavelength [tex]\lambda=489.2 nm =>4.86*10^{-7}[/tex]
nf level= Balmer series
nf level= 2
Generally the equation for Wavelength is mathematically given by
[tex]\frac{1}{\lambda}=R[\frac{1}{nf^2}-\frac{1}{n_1^2}][/tex]
Where
[tex]R=Rydberg Constant[/tex]
[tex]R=1.097*10^7[/tex]
Therefore
[tex]\frac{1}{4.86*10^{-7}}=1.097*10^7[\frac{1}{2^2}-\frac{1}{n_1^2}][/tex]
[tex]n_1=4.0021[/tex]
[tex]n_1=4[/tex]
8. Build a neutral lithium atom.
Now, what must you do to make the lithium atom's charge change to +1?
Hint: Lithium is atomic number 3.
Add 2 electrons
Remove 1 electron
Add 1 electron
Add 1 proton
Answer:
Remove 1 electron
Explanation:
In the atom of each element, there are three subatomic particles viz: proton, neutron and electron. The number of proton (positively charged) and electron (negatively charged) determines the charge of that element. The more the proton, the more positively charged an ion is and vice versa for electron.
According to this question, a neutral atom of lithium (Li) with atomic no. 3 is given i.e. a lithium atom with charge 0. To make the lithium atom's charge change to +1, ONE ELECTRON MUST BE REMOVED OR LOST.
Note that, the proton number (atomic number) of an element does not change, rather the electron number changes in relation to the no. of protons.
Equimolar solutions of A and B are mixed and the reaction is allowed to reach equilibrium. Write down the reactio that correctly describes the relative concentrations at equilibrium?
Complete Question
Complete Question is attached below
Answer:
Option A
[tex]D=A[/tex] And [tex]C>A[/tex]
Explanation:
From the question, we are told that:
The Chemical Reaction
[tex]2A_{aq}+B_{aq} \leftrightarrow 3C_{aq}+2D_{aq}[/tex]
Generally, the equation for Equilibrium constant is mathematically given by
[tex]K=\frac{C^c*D^d}{A^a*B^b}[/tex]
Therefore
[tex]K=\frac{C^3*D^d}{A^2*B^b}[/tex]
Hence we conculde
[tex]D=A[/tex] And [tex]C>A[/tex]
Therefore Option A
Why U.S. genetically modified ingredients ruin the taste
Answer:
I hope this helps!
Explanation:
The biggest threat caused by GM foods is that they can have harmful effects on the human body. It is believed that consumption of these genetically engineered foods can cause the development of diseases which are immune to antibiotics. ... As the health effects are unknown, many people prefer to stay away from these foods.
Why does nitrogen not show allotropy?
Answer:
Nitrogen does not show allotropy because of its small size and high electronegativity. The single N-N bond is weaker than P-P bond because of high inter electronic repulsions among non-bonding electrons due to the small bond distance. Hence it does not show allotropy.
Answer:
The nitrogen atom has short inter-bond distance, hence highly electronegative in terms of magnitude. This creates no relation in energy varieties hence no allotropes formed.
Nitrogen atom is also very small.
A buffer is a solution that is a mixture of either a weak acid and its conjugate base or a weak base and its conjugate acid. When strong acids or strong bases are added, buffers either accept protons when they are in excess or donate protons when they have been depleted to minimize changes in pH. Which of the statements correctly describe the properties of a buffer?
a. The conjugate base of an acidic buffer will accept hydrogen protons when a strong acid is added to the solution.
b. An acidic buffer solution is a mixture of a weak acid and its conjugate base.
c. An acidic buffer solution is a mixture of a weak base and its conjugate acid.
d. The weak acid of an acidic buffer will accept hydrogen protons when a strong base is added to the solution.
e. The weak acid of an acidic buffer will donate hydrogen protons when a strong base is added to the solution.
f. The conjugate base of an acidic buffer will donate hydrogen protons when a strong acid is added to the solution.
Answer:
a. The conjugate base of an acidic buffer will accept hydrogen protons when a strong acid is added to the solution.
b. An acidic buffer solution is a mixture of a weak acid and its conjugate base.
e. The weak acid of an acidic buffer will donate hydrogen protons when a strong base is added to the solution.
Explanation:
Which of the statements correctly describe the properties of a buffer?
a. The conjugate base of an acidic buffer will accept hydrogen protons when a strong acid is added to the solution. TRUE. The conjugate base neutralizes the excess of hydrogen protons.
b. An acidic buffer solution is a mixture of a weak acid and its conjugate base. TRUE.
c. An acidic buffer solution is a mixture of a weak base and its conjugate acid. FALSE. This is a basic buffer solution.
d. The weak acid of an acidic buffer will accept hydrogen protons when a strong base is added to the solution. FALSE. The weak acid will react with the hydroxyl ions from the added base.
e. The weak acid of an acidic buffer will donate hydrogen protons when a strong base is added to the solution. TRUE. These hydrogen protons will form water.
f. The conjugate base of an acidic buffer will donate hydrogen protons when a strong acid is added to the solution. FALSE. It will accept hydrogen protons.
Write chemical equations for the reactions that occur when solutions of the following substances are mixed:
a. HNO₂ (nitrous acid) and C₂H₇NO (aq) ethanolamine, a base.
b. H₃O+ and F-
a) HNO₂ + C₂H₇NO → N₂ + C₂H₆O + H₂O
b) H₃O⁺ + F⁻ → HF + H₂O
[tex]\large\color{lime}\boxed{\colorbox{black}{Answer : - }}[/tex]
a) HNO₂ + C₂H₇NO → N₂ + C₂H₆O + H₂O
b) H₃O⁺ + F⁻ → HF + H₂O
draw styrene
draw the structure of cyrene
5. For Sodium, the Work Function is listed as 2.75 eV but the Ionization Energy is listed as 5.14 eV. Is one of the experiments wrong? Give a possible explanation as to this difference in the minimum energy needed to eject or free an electron from Sodium.
Answer:
See explanation
Explanation:
The work function of a metal is defined as that minimum energy which is required to remove one electron from the surface of a metal when it is irradiated with a photon of light. The work function is different for different metals.
The ionization energy of a metal is the energy required to remove an electron from an atom. It depends on the position of the electron within the atom.
The work function specifically refers to the energy required to remove an electron from the conduction band of a metal. Hence, the work function is always lower than the ionization energy.
Sodium acetate
NaC2H3O2
SC2H3O2
Na2C2H3O2
Answer:
Sodium acetate is NaC2H3O2
Answer:
The answer is A for the lazy people.
A strawberry nutritional drink used for a liquid diet is flavored with methyl butanoate. Draw the structure of methyl butanoate.
Answer:
See explanation and image attached
Explanation:
Methyl butanoate is an ester. Esters have the general molecular formula, RCOOR where the two Rs may represent the same or different alkyl groups.
Methyl butanoate is has a fruity odor, smelling like apples or pineapples fragrance. It is also called methyl butyrate.
The structure of the compound is shown in the image attached to this answer.
Which are the following exothermic or endothermic
Absorbs Energy
-Hrxn
+Hrxn
Feels Hot
Heat flows from surrounds to Reaction
Not Energetically Favorable
Energetically Favorable
Releases Energy
Feels Cold
Heat flows from the reaction to the surrounds
Answer:
Explanation:
Your mom
Suppose a 0.034 M aqueous solution of sulfuric acid (H2SO4) is prepared. Calculate the equilibrium molarity of SO4 You'll find information on the properties of sulfuric acid in the ALEKS Data resource. Round your answer to 2 significant digits.
Answer:
[SO4²⁻] = 0.015M
Explanation:
When H2SO4 is dissolved in water, HSO4- is produced in a direct reaction as follows:
H2SO4 → HSO4- + H+
As 1 mole of H2SO4 produce 1 mole of HSO4-, the molarity of HSO4- in this first reaction is 0.034M
Now, the HSO4- is in equilibrium with SO42- and H+ as follows:
HSO4⁻ ⇄ SO4²⁻ + H⁺
Where the equilibrium constant, K, is defined as:
K = 1.2x10⁻² = [SO4²⁻] [H⁺] / [HSO4⁻]
Where [] are the equilibrium concentrations of each species in the reaction.
The equilibrium concentrations are:
[SO4²⁻] = X
[H⁺] = X
[HSO4⁻] = 0.034M - X
Where X is reaction coordinate
Replacing:
1.2x10⁻² = [X] [X] / [0.034-X]
4.08x10⁻⁴ - 1.2x10⁻²X = X²
4.08x10⁻⁴ - 1.2x10⁻²X - X² = 0
Solving for X:
X = -0.027M. False solution, there are no negative concentrations.
X = 0.015M. Right solution.
That means the equilibrium molarity of SO4²⁻,
[SO4²⁻] = X
[SO4²⁻] = 0.015MWhat volume of each solution contains 0.14 mol of KCl? Express your answer using two significant figures.
1.8 M KCl
Answer:
Solution given:
1 mole of KCl[tex]\rightarrow [/tex]22.4l
1 mole of KCl[tex]\rightarrow [/tex]74.55g
we have
0.14 mole of KCl[tex]\rightarrow [/tex]74.55*0.14=10.347g
74.55g of KCl[tex]\rightarrow [/tex]22.4l
10.347 g of KCl[tex]\rightarrow [/tex]22.4/74.55*10.347=3.11litre
volume of each solution contains 0.14 mol of KCl contain 3.11litre.
[tex]\:[/tex]
1 mole of KCl → 22.4l
1 mole of KCl → 74.55g
we have
0.14 mole of KCl → 74.55*0.14=10.347g
74.55g of KCl → 22.4l
10.347 g of KCl → 22.4/74.55*10.347=3.11litre
volume of each solution contains 0.14 mol of KCl contain 3.11litre.
Define pressure. Group of answer choices force exerted by solids to the surrounding area force used to compress a gas force used to melt a solid force exerted per unit area by gas particles as they strike the surfaces around them force applied to a gas to condense it
Answer:
force exerted per unit area by gas particles as they strike the surfaces around them
Explanation:
According to the kinetic molecular theory, a gas is composed of molecules. The molecules of a gas are in constant random motion and collide frequently with each other as well as with the walls of the container.
Pressure is defined as force per unit area. The pressure of a gas is the force exerted per unit area by gas particles as they strike the surfaces around them hence the answer above.
A sample of Kr gas is observed to effuse through a pourous barrier in 8.15 minutes. Under the same conditions, the same number of moles of an unknown gas requires 4.53 minutes to effuse through the same barrier. The molar mass of the unknown gas is ____________ g/mol.
Answer:
25.88 g/mol
Explanation:
Graham's law is a famous law which states that the diffusion rate or the effusion rate of any gas varies inversely to the square root of the molecular weight the gas.
So from Graham's law, we have,
[tex]$\frac{\text{time}}{M^{1/2}}=\text{constant}$[/tex]
Using the sample of Kr gas having M = 83.8
[tex]$\frac{8.15}{(83.8)^{0.5}}= \frac{4.53}{M^{0.5}}$[/tex]
[tex]$M^{0.5}= 5.088$[/tex]
M = 25.88 g/mol
Complete the sentences by identifying the correct missing words. Alph and beta particles originate from the Choose... . Protection from radiation is necessary because if radiation passes through the body it can damage Choose... . Exposure to radiation can be limited by increasing the Choose... from the radioactive source.
Answer:
Alpha and beta particles originate from the nucleus, protection from radiation is important because if the radiation passes through the body it can damage cells. Exposure to radiation is often limited by increasing the distance from the radioactive source.
Explanation:
Alpha and beta particles come from unstable atoms during their decay. This radiation is extremely harmful which may damage DNA, causing a high rate of mutation. If we increase the distance of the source of radioactive exposure we will prevent damage.How many moles of NiCl2 can be formed in the reaction of 7.00 mol of Ni and 14.0 mol of HCl?
Answer:
since the concentration of limiting reactant are the same for both nickel and hydrochloric acid, they both will produce the same amount if Nickel Chloride
7 mols of [tex]NiCl_2[/tex] formed in a reaction of 7 mol of Ni and 14 mol of HCl.
The moles of Ni = 7 mol
The mols of HCl = 14 mol
It is required to calculate moles of [tex]NiCl_2[/tex]
What is a mole?A mole corresponds to the mass of a substance that contains [tex]6.023 \times 10^{23}[/tex]particles of the substance. The mole is the SI unit for the amount of a substance. Its symbol is mol.
The reaction of Ni and HCl occurs as
[tex]Ni +2 HCl \to NiCl_2 + H_2[/tex]
Since the concentration of limiting reactant are the same for both nickel and hydrochloric acid, they both will produce the same amount of Nickel Chloride.
If we have 7 mols of Ni and 14 mols of HCl, then when the 7 moles of Ni has reacted, we will still have 7 moles of HCl unreacted.
So, the moles of [tex]NiCl_2[/tex] formed equal to the moles of Ni and HCl reacted.
Therefore, 7 mols of [tex]NiCl_2[/tex] formed in a reaction of 7 mol of Ni and 14 mol of HCl.
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Draw the organic product(s) of the following reaction.
NaNH2/ NH3(l)
CH2CH2CH2-Câ¡C -C-H â
Answer:
H-C = C-H NaNH2 [tex]\ \to \0}[/tex] H-C = CNa
H-C = C - CH2 CH2 CH2 CH3
Explanation:
NaNH2 acts as base in this reaction. The organic products released after the reaction of carbon hydrogen atom with sodium amide. These products released after the chemical reaction when carbon and hydrogen atom reacts and NaNH2 acts as base then substitution nucleophilic reaction takes place.
Adding more than one equivalent of HCl to pent-1-yne will lead to which product:______.
a. 1,2-dichloro-1-butene.
b. 1,1-dichloropentane.
c. 2,2-dichloropentane.
d. 2,2-dichlorobutane.
Answer:
c. 2,2-dichloropentane.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to firstly draw the structure of the reactant, pent-1-yne:
[tex]CH\equiv C-CH_2-CH_2-CH_2[/tex]
Now, we infer the halogen is added to the carbon atom with the most carbon atoms next to it, in this case, carbon #2, in order to write the following product:
[tex]CH\equiv C-CH_2-CH_2-CH_2+2HCl\rightarrow CH_3- CCl_2-CH_2-CH_2-CH_2[/tex]
Whose name is 2,2-dichloropentane.
Regards!
Which of the following statements is correct concerning the class of reactions to be expected for benzene and cyclooctatetraene?
A) Both substances undergo addition reactions.
B) Both substances undergo substitution reactions.
C) Benzene undergoes addition; cyclooctatetraene undergoes substitution.
D) Benzene undergoes substitution; cyclooctatetraene undergoes addition.
Answer:
Both substances undergo substitution reactions.
Explanation:
Let us go back to the idea of aromaticity. Aromatic substances are said to possess (4n + 2) π electrons according to Huckel rule.
Aromatic substances are unusually stable and the aromatic ring can not be destroyed by addition reactions.
Since both benzene and cyclooctatetraene are both aromatic, they do not undergo addition reactions whereby the aromatic ring is destroyed. They both undergo substitution reaction in which the aromatic ring is maintained.
The structure of the compound CuI is best described as a cubic closest packed array of iodide ions with the copper ions in tetrahedral holes. What percent of the tetrahedral holes are occupied in this solid
Answer:
12.5 %
Explanation:
In CCP, the effective number of anion is 4
That is there are 4 I- present in 1 unit cell
Number of tetrahedral void = 2*effective number of anion
= 2*4
= 8
In ZrI4, for every 4 anion, there are only 1 Zr atom.
So, one tetrahedral void is occupied per unit cell out of 8
% tetrahedral void occupied = 1*100/8
= 12.5 %
Answer: 12.5 %
Determine the highest level of protein structure described by each item.
a. Primary structure
b. Secondary structure
c. Tertiary structure
d. Quaternary structure
1. order of amino acids
2. overall macromolecule structure containing more than one polypeptide chain
From each of the protein structures listed, the option with the highest level of protein structure as regards with order of amino acids and overall macromolecule structure is quaternary structure. That is option D.
The protein one of the essential nutrients that is found in and consumed by mammals.
There are different types of proteins and their functions depends on their shape, structure or conformation.
The structure of proteins include:
Primary structure: This is the simplest shape of proteins. This is because, the amino acids of a polypeptide is arranged in a linear form.Secondary structure: This is the local folded structures that form within a polypeptide due to interactions between atoms of the backbone.Tertiary structure: These are three dimensional structures of proteins that occurs as a result of the interactions between the R groups of the amino acids that make up the protein.Quaternary structure: This protein structure contains multiple polypeptide chains also called subunits.Therefore, the option with the highest level of protein structure as regards with order of amino acids and overall macromolecule structure is quaternary structure.
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Write the complete ground-state electron configuration of I⁻.
Explanation:
here's the answer to your question
Iodine's neutral atom has the following electronic configuration: 1 s² 2 s² 2 p⁶ 3 s² 3 p⁶ 4 s² 3 d¹⁰ 4 p⁶ 5 s² 4 d¹⁰ 5 p⁵. The complete ground-state electron configuration of I⁻ is [Kr]5s² 4d¹⁰ 5p⁶.
What is electronic configuration?Electronic configuration is defined as each electron moves individually within an orbital while being surrounded by an average field produced by all other orbitals. The electron configuration is used to describe an atom's ground state orbitals, but it may also be used to depict an atom that has ionized into a cation or anion by making up for any lost or gained electrons in the orbitals after it.
The ground state electronic configuration is defined as the configuration of lower energy electrons surrounding an atom's nucleus. Ground state is defined as the least energetic state feasible for a physical system. It is important because permits us to determine the location of the excited electrons' departure and return when they release a photon.
Thus, iodine's neutral atom has the following electronic configuration: 1 s² 2 s² 2 p⁶ 3 s² 3 p⁶ 4 s² 3 d¹⁰ 4 p⁶ 5 s² 4 d¹⁰ 5 p⁵. The complete ground-state electron configuration of I⁻ is [Kr]5s² 4d¹⁰ 5p⁶.
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