An ideal gas expanded irreversibly against $10 \ bar$ pressure from $20 \ L$ to $30 \ L$. Calculate $Q$ if the process is isoenthalpic. $(1 \ L \ bar = 100 \ J)$

Calculate $\Delta H_f^o$ of $SiH_2$ from the following reactions:
$Si_2H_{6(g)} + H_{2(g)} \to 2SiH_{4(g)}, \Delta H = -11.7 \ kJ/mol$
$SiH_{4(g)} \to SiH_{2(g)} + H_{2(g)}, \Delta H = +239.7 \ kJ/mol$
$\Delta H_f^o(Si_2H_{6(g)}) = 80.3 \ kJ/mol$

Calculate the enthalpy change on freezing of $1.0 \ mol$ of water at $10.0^{\circ} C$ to ice at $-10.0^{\circ} C$. Given: $\Delta_{fus} H = 6.03 \ kJ \ mol^{-1}$ at $0^{\circ} C$,$C_p [H_2 O_{(l)}] = 75.3 \ J \ mol^{-1} \ K^{-1}$,$C_p [H_2 O_{(s)}] = 36.8 \ J \ mol^{-1} \ K^{-1}$.

Calculate the work done in $J$ when $63.50 \ g$ of $Zn$ is dissolved in an open beaker with hydrochloric acid at $300 \ K$. (Atomic mass of $Zn = 63.5 \ amu$)

For a reaction,$X_{2(g)} + Y_{2(g)} \rightleftharpoons 2XY_{(g)}$. If $\Delta G_r^o = 20 \ kJ \ mol^{-1}$ and $\Delta S_r^o = -20 \ J \ K^{-1} \ mol^{-1}$ at $200 \ K$. Calculate $\Delta H_r^o$ at $400 \ K$ (Given $\Delta_r C_P = 20 \ J \ K^{-1} \ mol^{-1}$).

$5$ moles of an ideal gas is expanded from $(10 \ L, 300 \ K)$ to $(20 \ L, 300 \ K)$ against a constant external pressure of $1.0 \ bar$. The only incorrect value of physical quantities for this change in state of the system,is-