What Is the Final State of an Ideal Gas After Temperature and Volume Changes?

[Questions999]

Homework Statement

A moster of a gas has 4 moles and first is in the temperature 300 K and pressure 10 atmosphere.After a change of state, ∆T= -50 K and ∆V=10 liter.Find the final temperature ,volume and pressure of the gas.

Homework Equations

P*v=n*R*T

The Attempt at a Solution

So T2-T1=-50 <=> T2=350-50=300 K
Now,to find V2, I thought : Find V1 first and then do V2-V1=∆V. From pv=nRT where T =300,pressure is 10 and the moles are 4. I Find that V1=997.2 here I replace V2-997.2=10 but V2 isn't the same as in my textbook..what did I do wrong

 

[haruspex]

So T2-T1=-50 <=> T2=350-50=300 K

Where did the 350 come from?

From pv=nRT where T =300,pressure is 10 and the moles are 4. I Find that V1=997.2

Seems too much. Please post the details of that calculation.

 

[Questions999]

Sorry,I know it is T2-T1=-50 and here I find that T2=250 Kelvin.

The details pv=nRT , V=(4*8.31*300)/10=997.2 litres..

 

[SteamKing]

What are the units of your gas constant R?

 

[Questions999]

R= 8.31 J *K−1 mol−1

 

[ap123]

SteamKing asked you about the units for the gas constant, because the units are wrong in your calculation of the initial volume.

Since it's best to stick to the units given in the question, use the gas constant
R = 0.08206 L.atm/K.mol

When you're putting numbers into an equation, always include the units and check what they give for the final answer. You can avoid a lot of errors doing this.