Which of the following material is used to make calorimeter?

$200 \,g$ of ice at $-20^{\circ} C$ is mixed with $500 \,g$ of water at $20^{\circ} C$ in an insulating vessel. Final mass of water in vessel is ........... $g$ (specific heat of ice $=0.5 \,cal g ^{-10} C ^{-1}$ )

A 'thermacole' icebox is a cheap and an efficient method for storing small quantities of cooked food in summer in particular. A cubical icebox of side $30 \,cm$ has a thickness of $5.0\; cm .$ If $4.0\; kg$ of ice is put in the box, estimate the amount of ice (in $kg$) remaining after $6 \;h$. The outside temperature is $45\,^{\circ} C ,$ and co-efficient of thermal conductivity of thermacole is $0.01\; J s ^{-1} m ^{-1} K ^{-1} .$ Heat of fuston of water $=335 \times 10^{3}\;J kg ^{-1} $

$2\  kg$ ice at $-20^o\ C$ is mixed with $5\  kg$ water at $20^o\ C$. Then final amount of water in the mixture would be ; Given specific heat of ice $= 0.5\ cal/g^o\ C$, specific heat of water $= 1\  cal/g^o\ C$, Latent heat of fusion of ice $= 80\  cal/g$ ........ $kg$

Two rigid boxes containing different ideal gases are placed on a table. Box A contains one mole of nitrogen at temperature $T_0$, while Box contains one mole of helium at temperature $(7/3)$ $T_0$ The boxes are then put into thermal contact with each other, and heat flows between them until the gases reach a common final temperature (ignore the heat capacity of boxes). Then, the final temperature of the gases,$T_f$  in terms of $T_0$ is

$10 \,\,gm$ of ice at $0^o C$ is kept in a calorimeter of water equivalent $10 \,\,gm$. ....... $cal$ heat should be supplied to the apparatus to evaporate the water thus formed? (Neglect loss of heat)