Question 371
CBSE Class 11 Chemistry · Equilibrium · Equilibrium constants and reaction quotient
Reaction between N2 and O2– takes place as follows: 2N2 (g) + O2 (g) 2N2O (g) If a mixture of 0.482 mol N2 and 0.933 mol of O2 is placed in a 10 L reaction vessel and allowed to form N2O at a temperature for which Kc= 2.0 × 10–37, determine the composition of equilibrium mixture.
Solution to Question 371
Complete workingLet x be the equilibrium N₂O concentration. Since K is extremely small, reactant concentrations remain essentially initial; solve Kc=x²/([N₂]²[O₂]).
\[\begin{aligned}[N_2]_0 &= 0.0482,\ [O_2]_0\\&= 0.0933\end{aligned}\]
\[x\approx\sqrt{(2.0\times10^{-37})(0.0482)^2(0.0933)}=6.6\times10^{-21}\ \mathrm M\]
Final answer
[N₂]=0.0482 M, [O₂]=0.0933 M, [N₂O]=6.6×10⁻²¹ M.