Heats of combustion of $C{H}_4,<mspace\; width="1em"></mspace>C_2{H}_4,<mspace\; width="1em"></mspace>C_2{H}_6$ are -890, -1411 and -1560 kJ/mole respectively. Which has the lowest fuel value in kJ/gm ?

1. $C{H}_4$

2. $C_2{H}_4$

3. $C_2{H}_6$

4. All same

The temperature of 5 ml of a strong acid increases by $5^{\circ }$ when 5 ml of a strong base is added to it. If 10 ml of each is mixed, temperature should increase by-

1. $5^{\circ }$

2. ${10}^{\circ }$

3. ${15}^{\circ }$

4. cannot be known

The heat of neutralisation of HCl by NaOH is -55.9 kJ/mole. If the heat of neutralisation of HCN by NaOH is -12.1 kJ/mole, then energy of dissociation of HCN is-

1. -43.8 kJ

2. 43.8 kJ

3. 68 kJ

4. -68 kJ

For a reaction at equilibrium-

1. $∆G=∆G^{\circ }=0$

2. $∆G=0<mspace\; width="1em"></mspace>but<mspace\; width="1em"></mspace>not<mspace\; width="1em"></mspace>∆G^{\circ }$

3. $∆G^{\circ }=0<mspace\; width="1em"></mspace>but<mspace\; width="1em"></mspace>not<mspace\; width="1em"></mspace>∆G$

4. $∆G=∆G^{\circ }\ne 0$

Using only the following data:

(I) $F{e}_2{O}_3\left(s\right)+3CO\left(g\right)\rightleftharpoons 2Fe\left(s\right)+3C{O}_2\left(g\right);$
$∆H^{\circ }=-26.8<mspace\; width="1em"></mspace>kJ$

(II) $$\begin{gathered} Fe\left(s\right)+C{O}_2\left(g\right)\rightleftharpoons FeO\left(s\right)+CO\left(g\right); \\ ∆H^{\circ }=+16.5<mspace\; width="1em"></mspace>kJ \end{gathered}$$

the $∆H^{\circ }$ value, in kilojoules, for the reaction

$F{e}_2{O}_3\left(s\right)+CO\left(g\right)\to 2FeO\left(s\right)+C{O}_2\left(g\right)$ is calculated to be:

1. -43.3

2. -10.3

3. +6.2

4. +10.3

82 litres of carbon dioxide are produced at a pressure of 1 atm by the action of acid on a metal carbonate. The work done at room temp by the gas (in calories) in pushing back the atmosphere is 

1. 1000

2. 820

3. 1640

4. 2200

Among the following, the reaction for which $∆H=∆E$ is-

1. $PC{l}_5\left(g\right)\to PC{l}_3\left(g\right)+C{l}_2\left(g\right)$

2. $H_2\left(g\right)+C{l}_2\left(g\right)\to 2HCl\left(g\right)$

3. $C_2{H}_{5}OH\left(l\right)+3O_2\left(g\right)\to 2C{O}_2\left(g\right)+3H_{2}O\left(l\right)$

4. $C_2{H}_4\left(g\right)+H_2\left(g\right)\to C_2{H}_6\left(g\right)$

For which change $∆H\ne ∆E$

1. $H_2+I_2\rightleftharpoons 2HI$

2. $HCl+NaOH\to NaCl+H_{2}O$

3. $C\left(s\right)+O_2\left(g\right)\rightleftharpoons C{O}_2\left(g\right)$

4. $N_2+3H_2\to 2N{H}_3$

Enthalpy change when 1.00 g water is frozen at $0^{\circ }C,$ is :

$\left(∆H_{fus}=1.435<mspace\; width="1em"></mspace>kcal<mspace\; width="1em"></mspace>mo{l}^{-1}\right)$

1. 0.0797 kcal

2. -0.0797 kcal

3. 1.435 kcal

4. -1.435 kcal