Question
Question: 1/2 mole of helium gas is contained in a container at S.T.P. The heat energy needed to double the pr...
1/2 mole of helium gas is contained in a container at S.T.P. The heat energy needed to double the pressure of the gas, keeping the volume constant (heat capacity of the gas = 3 Jg–1 K–1) is –
A
3276 J
B
1638 J
C
819 J
D
409.5 J
Answer
1638 J
Explanation
Solution
DQ = nCv DT, ms = g−Kel3J, nCv = 3
41 × Cv = 3 \Cv =mol−Kel12J, n¢Cv =21×12 = 6
DQ = n¢ Cv DT = 6 × 273 = 1638 J