A sample of gas is in a cylinder of fixed volume. At 30.0 °C its internal pressure is 3200.
torr. What will be its pressure at 12.0 ° C?

Question

A sample of gas is in a cylinder of fixed volume. At 30.0 °C its internal pressure is 3200.
 torr. What will be its pressure at 12.0 ° C?

aaronq · Answer

from the ideal gas law: $$PV=nRT  $$

$$\frac{ P _{1} }{ T _{1} }=\frac{ P _{2} }{ T _{2} }$$

plug in and solve

anonymous · Answer

3010. torr?

aaronq · Answer

not quite. what did you do?

joemc · Answer

I got 3010 torr, too.

anonymous · Answer

Yea, I'm pretty sure that's the answer to the equation.

aaronq · Answer

$$\frac{ 3200 torr }{ 30 C }=\frac{ P _{2} }{ 12C } \to P _{2}=\frac{ 3200 torr }{ 30 C }*12C \to P _{2}= 1280 torr$$

joemc · Answer

@aaronq, you have to use Kelvin.....

joemc · Answer

$$\frac{ 3200 torr }{303.15 K } = \frac{ P_2 }{ 285.15 K } =  \frac{3200 torr }{303.15 K } \times 285.15 K = P_2$$

aaronq · Answer

haha wow. FAIR ENOUGH