At (T( ~K ) ), if the ionisation constant of ammonia in solution is (2.5 10⁻⁵ ), the ( pH ) of (0.01 M ) ammonia solution and the ionisation constant of its conjugate acid respectively at that temperature are (( 2=0.30) )

Step-by-step solution

(K_a K_b=K_w=10⁻¹⁴ ) (at (25^ C )) where, (K_a= ) ionisation constant for acid ( ( NH ₄⁺ ) ) and (K_b= ) ionisation constant for base ( ( NH ₃ ) ) (=2.5 10⁻⁵ ) i.e. ( K_a ( NH ₄⁺ ) K_b ( NH ₃ )=10⁻¹⁴ ) ( gathered K_a ( NH ₄⁺ )= 10⁻¹⁴ K_a ( NH ₄⁺ ) K_a= 10⁻¹⁴ 2.5 10⁻⁵ =4 10⁻¹⁰ gathered ) i.e. ionisation constant of conjugate acid (=4 10⁻⁸ ) For ( pH ) of (0.01 M ) ammonia ( ( NH ₃ ) ) ( NH ₄ OH ) dissociate as : ( array llll & NH ₄ OH & NH ₄⁺ & + OH ⁻ At equilibrium & 0.01 (1- ) & 0. & 0.01 array ) ( ( ) Concentrati