2. A sample of oxygen gas is placed in a rigid 1.5L glass container at STP. If the gas is heated to 100 degrees (Celcius) what is the new pressure in mmHg?

The new pressure : P₂ = 1038.39 mmHg

Given

1.5 L container at STP

Heated to 100 °C

Required

The new pressure

Solution

Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure).

So P₁ =  1 atm = 760 mmHg

T₁ = 273 K

T₂ = 100 °C+273 = 373 K

Gay Lussac's Law  

When the volume is not changed, the gas pressure is proportional to its absolute temperature  

Input the value :

P₂=(P₁.T₂)/T₁

P₂=(760 x 373)/273

P₂ = 1038.39 mmHg

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"