A piston-cylinder device contains an ideal gas mixture of 3 kmol of He gas and 7 kmol of Ar gas (both gases are monatomic) at 27°C and 200 kPa. Now the gas expands at constant pressure until its volume doubles. The amount of heat transfer to the gas mixture is, in MJ (round to nearest integer; for example if the answer is 53.7MJ, write 54; if the answer is 52.1MJ write 52; do not include the units in your answer)

Q = 62    ( since we are instructed not to include the units in the answer)

Explanation:

Given that:

Q = ???

Now the gas expands at constant pressure until its volume doubles

i.e if

Using Charles Law; since pressure is constant

mass of He =number of moles of He × molecular weight of He

mass of He = 3 kg  × 4

mass of He = 12 kg

mass of Ar =number of moles of Ar × molecular weight of Ar

mass of He = 7 kg  × 40

mass of He = 280 kg

Now; the amount of  Heat  Q transferred =

From gas table

∴ Q =

Q =

Q = 62 MJ

Q = 62    ( since we are instructed not to include the units in the answer)

this is true

explanation:

i looked it up