Question

A manometer attached to a flask contains NH3 gas have no difference in mercury level initially. after the sparking into the flask ,it have difference of 6 cm in mercury level in two columns. what is partial pressure of h2 at equilibrium

Answer 1

2NH3 ----> N2 + 3H2

Initially, pressure will 76 ----> 0 , 0

When it attains equilibrium, pressure will be 76 – 2x ----> x , 3x

After dissociation total pressure will be = 76 – 2x + x + 3x = 76 + 2x

We can see that increase in pressure of Hydrogen is 76 - (76+2x) = 2x

It is given that difference in mercury level is 6cm

Therefore , 2x = 6

x = 3 cm.

Partial pressure of Hydrogen is 3x = 3*3 = 9 cm Hg

Answer 2

Answer:

after x = 3 cm

how partial pressure of H2 is 3x .

mole fraction of H2 is 3 / 4

so it should be 3x / 4 instead of 3x