The pressure exerted by 2.5 moles of helium gas in a 1.25 liter balloon is 3.45 atmospheres.?

Question

What is the temperature of the balloon?
We do not have enough information to answer this question.
0.0821 Kelvin
1.73 Kelvin
21.0 Kelvin

Answer 1

Use the ideal gas equation (molar form)

pV = nRT

T = pV/nR

p = 3.45 atm = 3.45x10^5 Pa
V = 1.25 litres = 0.00125 m^3
n = 2.5 moles
R = universal gas constant = 8.314472(15) J · K-1 · mol-1

Hence T = 21 K