Question

The unit of Kc for reaction N2 + O2 → 2NO

(a) mol dm–3

(b) mol–1

dm3

(c) mol–2

dm6

(d) no units​

Answer 1

Answer:

(d)

Explanation:

Kc = (mol/L)2/(mol/L)2 hence no units

Answer 2

The unit of Kc for reaction $N_{2} + O_{2}$ → $2NO$ has no units.

• $K_{c}$ is the symbol that is used to denote the equilibrium constant of concentrations involved in a chemical reaction.
• When equilibrium is reached of any chemical reaction then it depicts the relationship between the concentrations of both the compounds of reactant as well as product side.
• $K_{c}$ is formulated by the concentration of the compounds at the product side divided by the concentration of the compounds at the reactant side, each raised to the power of their stoichiometric coefficients when the reaction occurring attains equilibrium.

• $K_{c}$ =  $\frac{[C^{c}] [D^{d}] }{[A^{a}] [B^{b}] }$

• So, using this formula for the equation,

• $N_{2} + O_{2}$ → $2NO$ and as the units of concentration of any compound is mol/L.

• Thus, $K_{c} = \frac{[NO]^{2} }{[N_{2}] ^{1} [O_{2}] ^{1} } = \frac{(mol/L)^{2} }{(mol/L)^{2} }$ = no units.

Hence, d is the correct option.