Question

An ideal gas at 65 °C occupies a volume of 2.5 L at a pressure of 3.4 atm. How many moles of gas are present in the sample? (R = 0.08206 L·atm/mol·K)

Answer 1

3.3 moles


0.63 moles


0.31 moles


1.6 moles

Answer 2

@Preetha @aaronq @sweetburger

Answer 3

Use the ideal gas equation
\[PV=nRT\]

Answer 4

P: Pressure
V: Volume
n: no. of moles
R: ideal gas constant
T: Absolute temperature

Answer 5

Okay, would the answer be B?

Answer 6

@Prathamesh_M

Answer 7

@mathmate @Preetha @sweetburger @aaronq
Can you help me?

Answer 8

I think u made a mistake

Answer 9

Be sure to enter the temperature in the Kelvin scale in the ideal gas equation.

Answer 10

Oh okay, i knew something was wrong.
Would the answer then be D?

Answer 11

What about now?

Answer 12

Nope u would get D if u enter temperature as 65

Answer 13

Enter temperature as 338(Kelvin scale)

Answer 14

The other values are as they are given in the question

Answer 15

Okay I think I did it right this time. The answer would be A, right?

Answer 16

@Prathamesh_M

Answer 17

@Photon336

Answer 18

It's not B, it"s not D, and if it's not A, then it must be D, right?
@shall29 , you're here to learn about the ideal gas law, not how to guess!

@Prathamesh_M already gave you the formula
PV=nRT
of which you know
P=3.4 atm
V=2.5 L
R=0.08206 L-atm/(mol- deg.K)
T=65 deg.C which should be converted to 65+273.15=338.15 deg. K
The only unknown that you're look for is n=number of moles.
So please take out your calculator and work out n instead of guessing.

Answer 19

Hi @mathmate. I worked it out on my calculator and got 3.3 moles, A.

Answer 20

I won't confirm or deny until you show me how you did it.
As @agentosmith said, the right method would give you the right answer.
So the method is more important than the answer choice.

Answer 21

Okay sure.
3.4 x 2.5 = 8.5
0.08206 x 338.15 = 27.748589
27.748589 divided by 8.5
Then I got about 3.3