Laws of Gas in Chemistry

Question

1. What is the temperature in °C, when a piston reduces a volume of 350 mL of NO2 gas at 36°C to 150 mL at a constant pressure?  
2. What is the new pressure of CO2 in atm, when a 10 mL container is expanded to 25 mL while the temperature is lowered from 35°C to 10°C? The initial pressure in the container was 1.3 atm. For your answer just enter the values with the proper sig figs. No unit is necessary.

Answer 1

V1 = 350 ml

T1 = 36ºC + 273 = 309K

V2 = 150 ml

T2 = ?

At constant pressure, we are dealing with Charles Law:

V1/T1 = V2/T2

350 ml/309K = 150 ml/T2

T2 = (150 ml)(309K)/350 ml

T2 = 132.4K - 273 = -141ºC

V1 = 10 ml

T1 = 35ºC + 273 = 308K

P1 = 1.3 atm

V2 = 25 ml

T2 = 10ºC + 273 = 283K

P2 = ?

Here you are dealing with the combined gas law: P1V1/T1 = P2V2/T2

(1.3atm)(10ml)/308K = (P2)(25ml)/283

Solve for P2