4. Chemical bonding and molecular structure — Chemistry STD 11 Science — Question

$(i)$ $P{b^{2 + }} > P{b^{4 + }},T{l^ + } < T{l^{3 + }}$         $(ii)$ $Bi^{3+} < Sb^{3+} , Sn^{2+} < sn^{4+}$

$(iii)$ $P{b^{2 + }} > P{b^{4 + }},B{i^{3 + }} > B{i^{5 + }}$     $(iv)$ $T{l^{3 + }} < I{n^{3 + }},S{n^{2 + }} > S{n^{4 + }}$

$(v)$ $S{n^{2 + }} < P{b^{2 + }},S{n^{4 + }} > P{b^{4 + }}$     $(vi)$ $S{n^{2 + }} < P{b^{2 + }},S{n^{4 + }} < P{b^{4 + }}$

[$A$] The work done on the gas is maximum when it is compressed irreversibly from ( $\mathrm{p}_2, \mathrm{~V}_2$ ) to ( $\mathrm{p}_1, \mathrm{~V}_1$ ) against constant pressure $\mathrm{pl}_1$

[$B$] The work done by the gas is less when it is expanded reversibly from $V_1$ to $V_2$ under adiabatic conditions as compared to that when expanded reversibly from $V_1$ to $V_2$ under isothermal conditions

[$C$] The change in internal energy of the gas is ($i$) zero, if it is expanded reversibly with $T_1=T_2$, and ($ii$) positive, if it is expanded reversibly under adiabatic conditions with $T_1 \neq T_2$

[$D$] If the expansion is carried out freely, it is simultaneously both isothermal as well as adiabatic