When a solid melts reversibly :

• H decreases

• G increases

• E decreases

• S increases

Enthalpy is equal to :

• ${\mathrm{T}}^2{\left[\frac{\partial (\mathrm{G}/\mathrm{T})}{\partial \mathrm{T}}\right]}_P$

• $-{\mathrm{T}}^2{\left[\frac{\partial (\mathrm{G}/\mathrm{T})}{\partial \mathrm{T}}\right]}_{\mathrm{P}}$

• ${\mathrm{T}}^2{\left[\frac{\partial (\mathrm{G}/\mathrm{T})}{\partial \mathrm{T}}\right]}_V$

• $-{\mathrm{T}}^2{\left[\frac{\partial (\mathrm{G}/\mathrm{T})}{\partial \mathrm{T}}\right]}_{\mathrm{V}}$

Condition for spontaneity in an isothermal process is

• $∆\mathrm{A} + \mathrm{W} < 0$

• $∆\mathrm{G} + \mathrm{U} <0$

• $∆\mathrm{A} + \mathrm{U}>0$

• $∆\mathrm{G} -\mathrm{U}<0$

$$\begin{gathered} 2\mathrm{C}\left(\mathrm{s}\right) + 2{\mathrm{O}}_2\left(\mathrm{g}\right) \to 2{\mathrm{CO}}_2\left(\mathrm{g}\right); ∆\mathrm{H}= -787 \mathrm{kJ} ....\left(\mathrm{i}\right) \\ {\mathrm{H}}_2\left(\mathrm{g}\right) + \frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right) \to {\mathrm{H}}_2\mathrm{O} \left(\mathrm{l}\right); ∆\mathrm{H} = -286 \mathrm{kJ} ...\left(\mathrm{ii}\right) \\ {\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{g}\right) + 2\frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right) \to 2{\mathrm{CO}}_2\left(\mathrm{g}\right) + {\mathrm{H}}_2\mathrm{O} \left(\mathrm{l}\right) ; ∆\mathrm{H}= -1310 \mathrm{kJ} ...\left(\mathrm{iii}\right) \end{gathered}$$

The heat of formation of acetylene is :

• -1802 kJ

• +1802 kJ

• +237 kJ

• -800 kJ

5.

Given the equilibrium system:

${\mathrm{NH}}_4\mathrm{Cl}\left(\mathrm{s}\right) \to {\mathrm{NH}}_4^{+}\left(\mathrm{aq}\right) + {\mathrm{Cl}}^{-}\left(\mathrm{aq}\right) (∆\mathrm{H} =+3.5 \mathrm{kcal}/\mathrm{mol}).$

What change will shift the equilibrium to the right?

• Decreasing the temperature

• Increasing the temperature

• Dissolving NaCl crystals in the equilibrium mixture

• Dissolving NH₄NO₃ crystals in the equilibrium mixture

Equivalent amounts of H₂ and I₂, are heated in a closed vessel till equilibrium is obtained. If 80% of the hydrogen can be converted to HI, the K_c at this temperature is :

• 64

• 16

• 0.25

• 4

For the reaction ${\mathrm{H}}_2\left(\mathrm{g}\right) + {\mathrm{I}}_2\left(\mathrm{g}\right) \to 2\mathrm{HI}\left(\mathrm{g}\right),$ the equilibrium constant K_P changes with: 

• total pressure

• catalyst

• the amount H₂ and I₂

• temperature

In TeCl₄ the central atom tellurium involves :

• sp³ hybridisation 

• sp³d hybridisation 

• sp³d² hybridisation 

• dsp² hybridisation 

A nuclear reaction of ${}_{92}{}^{235}\mathrm{U}$ with a neutron produces ${}_{36}{}^{90}\mathrm{Kr}$ and two neutrons. Other element produced in this reaction is

• ${}_{52}{}^{137}\mathrm{Te}$

• ${}_{55}{}^{144}\mathrm{Cs}$

• ${}_{56}{}^{137}\mathrm{Ba}$

• ${}_{56}{}^{144}\mathrm{Ba}$

A coordiante bond is a dative covalent bond. Which of the below is true?

• Three atom form bond by sharing their electrons

• Two atom form bond by sharing their electrons

• Two atoms form bond and one of them provides both electrons

• Two atoms form bond by sharing electrons obtained from third atom