A gas has an initial pressure of 51 kPa with a volume of 1.0 liter and a temperature of 320K What is the temperature of the gas when it has a pressure of 85 kPa and a volume of 2.1 liters

See below

Explanation:

Use the combined gas law where:

P₁V₁       P₂V₂

 =        You are looking for T₂.

 T₁           T₂

You can either solve the equation above to T₂ now and then plug the number in or you can plug the numbers in now and solve.  Do the latter.

(51)(1.0)       (85)(2.1)

 =  

  320              T₂

Cross-multiply and you get:

(51)T₂ = (85)(2.1)(320)  or T₂ = (85)(2.1)(320) / 51

T₂ = 1120 K

this means that the temperature of both substances will be equal

there are no contact forces mentioned on the list of choices that you've provided.