Combined gas law problems

Question

I can’t understand this question and I’m hoping someone can assist me with it

A 4.0 mole sample of gas occupies 4.4 liters at STP, which is 273 k and 1 atm. If more gas is added to the balloon the volume increases to 6.7 liters and the number of moles is now 7.3 moles, and the pressure is now at 3.4 atm. What is the new temperature

Answer 1

This is a problem dealing with a modification of the combined gas law:

P1V1/n1T1 = P2V2/n2T2

P1 = initial pressure = 1 atm

V1 = initial volume = 4.4 L

n1 = initial moles = 4.0

T1 = initial temperature = 273K

P2 = final pressure = 3.4 atm

V2 = final volume = 6.7 L

n2 = final moles = 7.3

T2 = final temperature = ?

Plugging the values in and solving for T2, we have...

(1 atm)(4.4 L)/(4.0 mol)(273K) = (3.4 atm)(6.7 L)/(7.3 mol)(T2)

T2 = 774K