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 ...... $J$.

$1\;g$ of water,of volume $1\;cm^{3}$ at $100^{\circ}C$,is converted into steam at the same temperature under normal atmospheric pressure $(=1 \times 10^{5}\;Pa)$. The volume of steam formed equals $1671\;cm^{3}$. If the specific latent heat of vaporisation of water is $2256\;J/g$,the change in internal energy is.....$J$.

Given that $1\,g$ of water in liquid phase has volume $1\,cm^3$ and in vapour phase $1671\,cm^3$ at atmospheric pressure and the latent heat of vaporization of water is $2256\,J/g$,the change in the internal energy in joules for $1\,g$ of water at $373\,K$ when it changes from liquid phase to vapour phase at the same temperature is ....... $J$.

If the amount of heat given to a system is $35 \ J$ and the amount of work done by the system is $-15 \ J$,then the change in the internal energy of the system 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:

If $150 \ J$ of heat is added to a system and the work done by the system is $110 \ J$,then the change in internal energy will be .......... $J$.