Answer:
[tex]dQ=-500J[/tex]
Explanation:
We have given work is done on the gas is 1200 J
So work done will be [tex]dW=-1200J[/tex] ( as work is done on the gas )
It is given that internal energy is increases by exactly 700 J
So [tex]dU=700J[/tex]
From thermodynamic equation [tex]dQ=dU+dW[/tex]
So [tex]dQ=700-1200=-500J[/tex]
Here negative sign indicates that heat flow out of the gas
If heat was negative then heal was flowing in the gas