Asample of gas occupies a volume of 50.0 milliliters in a cylinder with a movable piston. the pressure of the sample is 0.90 atm and the temperature is 298k. what is the volume of the sample at stp?

The new volume is 41 mL.
Explanation:
Use the combined gas law
P
1
V
1
T
1
=
P
2
V
2
T
2
.
STP=273.15 K and 1 atm
Given/Known
P
1
=
0.90 atm

V
1
=
50.0 mL

T
1
=
298 K

P
2
=
1 atm

T
2
=
273.15 K
Unknown
V
2
Solution
Rearrange the equation to isolate
V
2
and solve.
P
1
V
1
T
1
=
P
2
V
2
T
2
V
2
=
P
1
V
1
T
2
T
1
P
2
V
2
=
0.90
atm
×
50.0
mL
×
273.15
K
298
K
×
1
atm
=
41 mL

The answer would be