5. Thermodynamics and thermochemistry — Chemistry STD 11 Science — Question

$2 SO _2( g )+ O _2( g ) \rightleftharpoons 2 SO _3( g ), \Delta H =-190\,kJ$

The number of factors which will increase the yield of $SO _3$ at equilibrium from the following is $.............$.

$A.$ Increasing temperature

$B.$ Increasing pressure

$C.$ Adding more $SO _2$

$D.$ Adding more $O _2$

$E.$ Addition of catalyst

$\frac{1}{2}{P_4}(s) + 3C{l_2}(g) \to 2PC{l_3}(l)\,;$     $\Delta H=-635 \,kJ$

$PC{l_3}(l) + C{l_2}(g) \to PC{l_5}(s)\,;$     $\Delta H=-137\, kJ$

The value of heat of formation of $PCl_5$ is ......$kJ\,mol^{-1}$