Question

A 0.10 M solution of a weak monoprotic acid has a hydronium-ion concentration of 5.0 ´ 10-4 M. What is the equilibrium constant, Ka, for this acid?



a. 5.0 ´ 10-2

b. 5.0 ´ 10-3

c. 2.5 ´ 10-4

d. 2.5 ´ 10-5

e. 2.5 ´ 10-6




2. (Points: 1)
What is the carbonate-ion, CO3-2, concentration in a 0.037 M carbonic acid solution?



a. 1.2 ´ 10-4

b. 4.2 ´ 10-7

c. 7.6 ´ 10-8

d. 4.8 ´ 10-11

e. 5.2 ´ 10-19




3. (Points: 1)
Which solution would show the GREATEST change in pH on the addition of 10.0 mL of 1.0 M NaOH to 1.0 L of each of the following solutions?



a. 0.50 M CH3COOH + 0.50 M NaCH3COO.

b. 0.10 M CH3COOH + 0.10 M NaCH3COO.

c. 0.50 M CH3COOH.

d. 0.10 M CH3COOH.

e. 0.50 M NaCH3COO.



4. (Points: 1)
Which of the following, when added to water, will not change the pH?



a. NaHCO3

b. NH4NO3

c. K2SO3

d. KI

e. HCN


can u please show me working out, i am in emergency.

Answer 1

A 0.10 M solution of a weak monoprotic acid has a hydronium-ion concentration of 5.0 ´ 10^-4 M. What is the equilibrium constant, Ka, for this acid?



a. 5.0 ´ 10^-2

b. 5.0 ´ 10^-3

c. 2.5 ´ 10^-4

d. 2.5 ´ 10^-5

e. 2.5 ´ 10^-6




2. (Points: 1)
What is the carbonate-ion, CO3^-2, concentration in a 0.037 M carbonic acid solution?



a. 1.2 ´ 10^-4

b. 4.2 ´ 10^-7

c. 7.6 ´ 10^-8

d. 4.8 ´ 10^-11

e. 5.2 ´ 10^-19

Answer 2

too many questions in one post. Pick one or two that represent types and repost.

Answer 3

Question 3
Answer: B