Question

In the reaction $A + 2 B$⇌, if 2 moles of moles of and 2.0 moles of are placed in a flask and the equilibrium concentration of is 0.5 mole/$l$. The equilibrium constant $\left( K _ { c } \right)$ for the reaction is.

• A. 0.073
• B. 0.147
• C. 0.05
• D. 0.026

Answer 1

Answer: (C)

0.05

Answer 2

A + 2B ⇌ 2C

Initial conc. 2 3 2

at eqm. 2.5 4 1

Molar $\frac { 2.5 } { 2 } = 1.25$ $\frac { 4 } { 2 } = 2$ $\frac { 1 } { 2 } = 0.5$

$K = \frac { [ 0.5 ] ^ { 2 } } { [ 1.25 ] \times [ 2 ] ^ { 2 } } = 0.05$