Why does a gas get heated on compression?

$110\; J$ of heat is added to a gaseous system,whose internal energy change is $40\; J$,then the amount of external work done is ........ $J$.

Consider one mole of perfect gas in a cylinder of unit cross-section with a piston attached as shown in the figure. $A$ spring (spring constant $k$) is attached (unstretched length $L$) to the piston and to the bottom of the cylinder. Initially,the spring is unstretched and the gas is in equilibrium. $A$ certain amount of heat $Q$ is supplied to the gas,causing an increase in volume from $V_0$ to $V_1$.
$(a)$ What is the initial pressure of the system?
$(b)$ What is the final pressure of the system?
$(c)$ Using the first law of thermodynamics,write down a relation between $Q, V_0, V_1, P_a$ and $k$.

$A$ monoatomic gas of $n$ moles is heated from temperature $T_1$ to $T_2$ under two different conditions: $(i)$ at constant volume and $(ii)$ at constant pressure. The change in internal energy of the gas is

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,where $\Delta U$ is the change in internal energy.

If heat is added at constant volume,$6300 \ J$ of heat are required to raise the temperature of an ideal gas by $150 \ K$. If instead,heat is added at constant pressure,$8800 \ J$ are required for the same temperature change. When the temperature of the gas changes by $300 \ K$,the internal energy of the gas changes by ..... $J$.