For an isochoric process,which of the following relations is correct?

When heat is given to a gas in an isobaric process,then

The state of a thermodynamic system changes from $(1)$ $(P_1, V)$ to $(2P_1, V)$ and $(2)$ $(P, V_1)$ to $(P, 2V_1)$. The work done during these two processes is respectively:

$A$ diatomic gas with rigid molecules does $10 \ J$ of work when expanded at constant pressure. What would be the heat energy absorbed by the gas,in this process ..... $J$.

$10 \text{ mole}$ of an ideal gas is undergoing the process shown in the figure. The heat involved in the process from $P_1$ to $P_2$ at constant volume $V = 1 \text{ m}^3$ is $\alpha \text{ Joule}$ ($P_1 = 21.7 \text{ Pa}$, $P_2 = 30 \text{ Pa}$, $C_v = 21 \text{ J/K} \cdot \text{mol}$, $R = 8.3 \text{ J/mol} \cdot \text{K}$). The value of $\alpha$ is . . . . . . .

Half a mole of an ideal monoatomic gas is heated at a constant pressure of $1\, atm$ from $20\,^oC$ to $90\,^oC$. The work done by the gas is close to ..... $J$ (Gas constant $R = 8.31\, J/mol\cdot K$).