For ( N H 4 ) 2 S ( s ) ⇌ 2N H 3 ( g ) + H 2 S ( g ) , K p = 1 0 5 tor r 3 . In a closed evacuated vessel, only NH₃ and H₂S are introduced at partial pressures 40 and 50 torr respectively. W

Question

For ( N H 4 ​ ) 2 ​ S ( s ) ⇌ 2N H 3 ​ ( g ) + H 2 ​ S ( g ) , K p ​ = 1 0 5 tor r 3 . In a closed evacuated vessel, only NH₃ and H₂S are introduced at partial pressures 40 and 50 torr respectively. What is the final total pressure?

TestHub · Accepted Answer

The reaction quotient, Q p ​ , is calculated as Q p ​ = ( 40 ) 2 ( 50 ) = 8 × 1 0 4 t or r 3 . Since this value is less than the equilibrium constant, K p ​ = 1 0 5 t or r 3 , the formation of solid (NH₄)₂S (the reverse reaction) is not favored. As no solid (NH₄)₂S was initially present in the vessel, further decomposition (the forward reaction) cannot produce more gas. Therefore, the total pressure remains 40 + 50 = 90 t orr . The correct option is A.

Chemistry - Chemical Equilibrium Question with Solution | TestHub

Options:

Doubts & Discussion

JEE Main 2027 (Class 12+)