Only a small fraction of a weak acid ionizes in aqueous solution. What is the percent ionization of a 0.100-M solution of acetic acid, CH3CO2H? CH3CO2H(aq)+H2O(l)⇌H3O+(aq)+CH3CO2−(aq )Ka=1.8×10−5
Answers
Answer:
1.33%
Explanation:
In an aqueous solution, a weak acid such as acetic acid, will be in equilibrium with its conjugate base, acetate ion, thus:
CH₃CO₂H(aq) + H₂O(l) ⇌ H₃O⁺(aq) + CH₃CO₂⁻(aq )
Where dissociation constant, ka, is defined as the ratio of concentrations of products and reactants:
Ka = 1.8x10⁻⁵ = [H₃O⁺] [CH₃CO₂⁻] / [CH₃CO₂H]
H₂O is not taken into account in the equilibrium because is a pure liquid
When a solution of acetic acid becomes to equilibrium, the original concentration of the acid decreases producing more H₃O⁺ and CH₃CO₂⁻.
The concentrations at equilibrium when a 0.100M solution of acetic acid reaches this state, is:
[CH₃CO₂H] = 0.100M - X
[H₃O⁺] = X
[CH₃CO₂⁻] = X
Where X is reaction coordinate.
Replacing in Ka expression:
1.8x10⁻⁵ = [H₃O⁺] [CH₃CO₂⁻] / [CH₃CO₂H]
1.8x10⁻⁵ = [X] [X] / [0.100M - X]
1.8x10⁻⁶ - 1.8x10⁻⁵X = X²
1.8x10⁻⁶ - 1.8x10⁻⁵X - X² = 0
Solving for X:
X = -0.00135 → False solution. There is no negative concentrations.
X = 0.00133 → Right solution.
That means concentration of acetate ion is:
[CH₃CO₂⁻] = 0.00133M.
Now, percent ionization is defined as 100 times the ratio between weak acid that is ionizated, [CH₃CO₂⁻] = 0.00133M, per initial concentration of the acid, [CH₃CO₂H] = 0.100M. Replacing:
% Ionization = 0.00133M / 0.100M × 100 =
1.33%
Related Questions
Explain why benzoic acid is able to be separated from acetanilide using sodium bicarbonate.
What point does the ammonium ions act as a buffer solution? Please this is driving me insane.
Which of the following statements best describes why strong acids and strong bases are good electrolytes?. . A. Strong acids and strong bases make water less pure.. . B. Strong acids and strong bases combine to form salts.. . C. Strong acids and strong bases neutralize each other.. . D. Strong acids and strong bases completely dissociate in water.. .
How many moles are present in 4.7 liters of Argon gas at STP?
Answers
Answers
A physical change in a substance doesn't change what the substance is.
A Chemical change, there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.
B) unequal heating of different parts of earth
C) differences in elevation on different landmasses
D) greenhouse gases
(no guessing please )
Answers
sometimes the earths heating of the surface is unequal forming global wind patterns
(2) decomposition of the solute
(3) evaporation of the solvent
(4) titration
Answers
Answer:
4) titration
Explanation:
Titration is a standard process used in a laboratory to determine the concentration of an unknown analyte. A titrant of known concentration is gradually added to a known volume of the analyte in the presence of a suitable indicator. The end of the titration is marked by a color change of the analyte.
The given example is that of an acid(HBr) - base(NaOH) titration which can be represented by the following equation:
NaOH + HBr → NaBr + H2O
Thus 1 mole of acid gets neutralized by 1 mole of the base to form 1 mole of the salt (NaBr)
Let M1 and V1 are the molarity and volume of the base (NaOH). Here, the molarity of NaOH is known = M1 = 0.10 M and the volume, V1 corresponds to the end point in the titration.
M2 and V2 are the molarity and volume of HBr. Here, V2 is known whereas M2 needs to be determined.
Based on the reaction stoichiometry:
moles of NaOH = moles of HBr
Answers
The red light appears first in the visible light spectrum as it exhibits the longest wavelength, and is refracted the least.
The relation between wavelength and refraction of light:
The phenomenon of bending of light as it moves from one medium to another is termed refraction. The intensity of refraction enhances with the decrease in the wavelength of light. The shorter wavelengths of light, that is, blue and violet are slowed more and at the same time experience more bending in comparison to the lights of longer wavelengths, that is, red.
The red color exhibits the longest wavelength and the slowest vibration, on the other hand, violet color exhibits the shortest wavelength and the fastest vibration of energy. The longer the wavelength, the less it is refracted and vice versa, This is the reason that red light appears first in the visible light spectrum.
Thus, the correct answer is option D.
Find out more information about the relation between wavelength and refraction here:
Answer:
c.
Explanation:
combustion
decomposition
single replacement
double replacement
Answers
Mg replaces the H in HCl to become MgCl2.