# Ideal gas law problem

does anyone know how to do this question. it feels like theres a part of the question missing as i dont know how to complete the equation

The pressure of a fixed mass of gas in a sealed sphere is measured to be 1.02 x 10^5 Pa at a temperature of 253K. Assuming the volume of the sphere doesnt change calculate the pressure within the sphere if the temperature is increased to 281K
(universal gas constant R =8314 J/K/mol

because it's a fixed mass of gas do i ignore n? when doing the equation

PV=nRT

## The Attempt at a Solution

(1.02 x 10^5) V = n (8314)(253)
1.02 x 10^5 V = 2103442n

Bystander
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i dont know how to complete the equation
What equation are you trying to complete?

the first part first of all,but there are two unknown variables so i'm not sure what to do

i know i need to find the volume of the sphere for the first part but iam unsure of how to get a number for n

Bystander
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How are you going to use the volume of the sphere once you get it?

when i have the volume i will use it to find the pressure like so

P = (n(8314)(281)) / V

Bystander
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when i have the volume i will use it to find the pressure like so
P = (n(8314)(281)) / V
unsure of how to get a number for n
So, what all has changed besides temperature and pressure?

nothing

Bystander
Homework Helper
Gold Member
Correct.
fixed mass of gas
volume of the sphere doesnt change
Just because the equation uses two variables, does not mean you have to find values for both if they're both constant, and you're interested in solving for the value of some other variable.

Thank you so much
:)