Question

A 1.00 liter solution contains 0.37 M nitrous acid and 0.48 M potassium nitrite. If 0.120 moles of calcium hydroxide are added to this system, indicate whether the following statements are true or false. (Assume that the volume does not change upon the addition of calcium hydroxide.) A. The number of moles of HNO2 will remain the same. B. The number of moles of NO2- will remain the same. C. The equilibrium concentration of H3O will remain the same. D. The pH will decrease. E. The ratio of [HNO2] / [NO2-] will remain the same.

Answer 1

Answer:

A. The number of moles of HNO2 will remain the same. True

B. The number of moles of NO2- will remain the same. False

C. The equilibrium concentration of H3O will remain the same. False

D. The pH will decrease. False

E. The ratio of [HNO2] / [NO2-] will remain the same. True

Explanation:

The mixture of nitrous acid and potassium nitrite is a buffer solution. Hence the properties outlined above. Buffer solutions are designed to militate against changes in acidity or alkalinity. This explains why the above statements were categorized as true or false accordingly.