Question

Which of the following aqueous solutions are good buffer systems?

(Select all that apply.)

a. 0.18 M nitrous acid + 0.13 M sodium nitrite
b. 0.27 M nitric acid + 0.25 M sodium nitrate
c. 0.29 M ammonia + 0.40 M potassium hydroxide
d. 0.15 M sodium hydroxide + 0.30 M sodium chloride
e. 0.32 M sodium chloride + 0.20 M calcium chloride

Answer 1

0.18 M nitrous acid + 0.13 M sodium nitrite is a good buffer system.

Hence, Option A is correct answer.

What is Buffer Solution ?

It is a solution that prevent any changes in the pH of the solution on the addition of an acidic and basic components.

What are the conditions for the goof buffer system ?

1. a weak acid and its conjugate base.
2. a weak base and its conjugate acid.

Now lets check all options one by one:

Option (A): 0.18 M nitrous acid + 0.13 M sodium nitrite

Nitrous acid is a weak acid and sodium nitrate is a conjugate base. This is a buffer.

Option (B): 0.27 M nitric acid + 0.25 M sodium nitrate

Nitric acid is a strong acid and sodium nitrate is neutral salt. So this is not good buffer.

Option (C):  0.29 M ammonia + 0.40 M potassium hydroxide

Potassium hydroxide is a strong base and Ammonia is also a strong base. So this is not a good buffer.

Option (D): 0.15 M sodium hydroxide + 0.30 M sodium chloride

Sodium hydroxide is a strong base and Sodium chloride is a ionic salt. So this is not a good buffer.

Option (E): 0.32 M sodium chloride + 0.20 M calcium chloride

Sodium chloride is a ionic salt and calcium chloride is a salt of strong acid. So this is not a good buffer.

Thus from the above conclusion we can say that 0.18 M nitrous acid + 0.13 M sodium nitrite is a good buffer system.

Hence, Option A is correct answer.

Learn more about the Buffer system here: https://brainly.com/question/3435382
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