Equilibrium Question 744
Question: The pH of a 0.01 M solution of a monobasic acid is four. Which one of the following statements about the acid is invorrec'
Options:
A) When a little NaOH is added, it will form a buffer solution
B) It is a weak acid
C) Its sodium salt will be acidic
D) Its sodium salt will be basic
Show Answer
Answer:
Correct Answer: C
Solution:
Concentration of monobasic acid=0.01 M $ pH=4 $ If the acid is completely ionized, the pH of the acid would be $ pH=-\log 0.01=-\log {10^{-2}}=2 $ So it is a weak acid. When the sodium salt of a weak acid is dissolved, the anions will be hydrolysed giving rise to $ O{H^{-}} $ ion concentration . The solution will be basic, So statement (3) is incorrect.