Answer:
m = 9.6 g
Explanation:
Thermal energy given to helium gas at constant volume is given as
[tex]Q = nC_v \Delta T[/tex]
so here we have
[tex]C_v = \frac{3}{2}R[/tex]
[tex]n = moles[/tex]
[tex]n = \frac{2}{4} = 0.5[/tex]
so we have
[tex]Q = \frac{3}{2}R(0.5)\Delta T[/tex]
now we know that
for oxygen gas we have
[tex]C_v = \frac{5}{2}R[/tex]
for same amount of heat we have
[tex]Q = nC_v \Delta T'[/tex]
[tex]\frac{3}{2}R(0.5)\Delta T = \frac{m}{32} (\frac{5R}{2}) \Delta T[/tex]
[tex]m = \frac{0.75 \times 32}{2.5}[/tex]
[tex]m = 9.6 g[/tex]