Question

If a sample of helium gas at 900 torr and 25°C is allowed to expand from 2.6 L to 5.8 L without changing the temperature, what pressure will the helium gas exert?

A)962 torr
B)275 torr
C)403 torr
D)2.01 x 103 torr

Answer 1

@Luigi0210

Answer 2

@ParthKohli

Answer 3

\[PV = nRT?\]

Answer 4

Ok I was using \[P(V_{1}/V _{2)}\] but I'll try that.

Answer 5

Or even\[P \propto T/V\]Using that equation.

Answer 6

I don't know what that equation is? what is the\[\alpha\] sign

Answer 7

Proportional to.

Answer 8

\[PV = nRT\]In this question, \(n\) and \(R\) are constant.

Answer 9

Even \(T\) is constant.

Answer 10

So \(\rm PV = constant \Rightarrow P \propto \dfrac{1}{V}\). There are only so many ways to get the answer to this question. :)

Answer 11

so if n R T are constant what would I put for n?

Answer 12

Nothing. Just ignore them.

If n (quantity of helium in moles), R (gas constant) and T (temperature) are constant according to the restrictions in the question, then nRT will also be constant.

Answer 13

From that, you get that \(\rm PV = constant\). Which tells you that \(\rm P\) and \(\rm V\) are inversely proportional. Do you know how to solve proportions?

Answer 14

Oh, and by the way, the formula you posted was correct.

Answer 15

this one P(V1/V2)?

Answer 16

403 torr?

Answer 17

Yes, but let's do it this way:\[\rm PV = constant\]Try plugging in \(\rm P\) and \(\rm V \), you will get the constant.

Answer 18

Seems good. :)

Answer 19

Thanks! should i still try the other way?

Answer 20

Probably not.

Answer 21

k thank you!

Answer 22

No problem.