For the gaseous reaction: C2H2 + D2O →C2D2 + H2O ΔH is 530 cal. At 25°C, KP = 0.82. Calculate how much C2D2 will be formed if 1 mole of C2H2 and 2 moles of D2O are put together at a total pressure of 1 atm at 100°C?

Q: For the gaseous reaction: C2H2 + D2O →C2D2 + H2O
ΔH is 530 cal. At 25°C , KP = 0.82. Calculate how much C2D2 will be formed if
1 mole of C2H2 and 2 moles of D2O are put together at a total pressure of 1 atm
at 100°C ?

Solution:   Firstly calculate KP at 100°C by using equation

$\large log\frac{(K_p)_{100^oC}}{(K_p)_{25^oC}} = \frac{\Delta H}{2.303 R} (\frac{T_2 -T_1}{T_1 T_2}) $

On solving we get, (KP)100°C = 0.98

C2H2 + D2O $ \rightleftharpoons $ C2D2 + H2O

Initial mole: 1      2          0       0

At eq. mole : 1–α  2–α      α      α

$0.98 =\frac{\alpha^2}{(1-\alpha)(2-\alpha)} $

0.02 α2 + 2.94 α – 1.96 = 0

On solving we get

α = 0.75