A mixture of helium and neon gases is collected over water at 28.0°C and 745 mmHg. If the partial pressure of helium is 368 mmHg, what is the partial pressure of neon?

1 Answer
Jun 28, 2016

#P_"Total"# #=# #P_"He"+P_"Ne"+P_"SVP"#

Explanation:

The partial pressures are additive; but to solve the problem we need 1 more parameter, #P_"SVP"#, the #"saturated vapour pressure"#, which is the #"vapour pressure"# of water at the given temperature. #P_"SVP"=18*mm*Hg# at #301*K#.

From above, #P_"Ne"=P_"Total"-P_"He"-P_"SVP"#

#=(745-368-18)*mm*Hg# #=# #??*mm*Hg#.