The first law of thermodynamics is concerned with the conservation of

When a system is taken from state $i$ to a state $f$ along path $iaf$,$Q = 50 \, J$ and $W = 20 \, J$. Along path $ibf$,$Q = 35 \, J$. If $W = -13 \, J$ for the curved return path $fi$,$Q$ for this path is ...... $J$.

$A$ unit mass of a liquid with volume $V_1$ is completely changed into a gas of volume $V_2$ at a constant external pressure $P$ and temperature $T$. If the latent heat of evaporation for the given mass is $L$,then the increase in the internal energy of the system is:

Which of the following is not a thermodynamic state function?

If $\Delta Q$ and $\Delta W$ represent the heat supplied to the system and the work done on the system respectively,then the first law of thermodynamics can be written as

The internal energy of an ideal gas is given by $U = 1.5 PV$. It expands from $10 \ cm^3$ to $20 \ cm^3$ against a constant pressure of $2 \times 10^5 \ Pa$. Heat absorbed by the gas in the process is (in $J$)