Question
Calculate the molar concentration of weak monobasic acid if K_a = 1.8 10^ -5 and degree of dissociation is 0.01 ?
MHT CET
Chemistry
Ionic Equilibrium
2026
MHT CET 2026 (19 April Shift 2)
MHT CET Chemistry Question (2026) — Solution
Options
- A. 1.8 10^ -1
- B. 1.8 10^ -2
- C. 5.55 10^ -3
- D. 5.55 10^ -4
Answer
A. 1.8 10^ -1
Step-by-step solution
For a weak monobasic acid, the dissociation constant is given by: K_a = C ^2 1- Since = 0.01, which is very small compared to 1, we can approximate 1- 1. K_a = C ^2 Rearranging for C: C = K_a ^2 Substituting the given values: C = 1.8 10^ -5 (0.01)^2 C = 1.8 10^ -5 10^ -4 C = 1.8 10^ -1 M Answer: 1.8 10^ -1
Related: Chemistry — Ionic Equilibrium · All PYQ Banks