9. Hydricarbon — Chemistry STD 11 Science — Question

$C_{(graphite)} +O_2(g) \rightarrow CO_2(g)\,;$

$\Delta _rH^o=-395.5 \, kJ\,mol^{-1}$

$H_2 (g) + \frac{1}{2} O_2 (g) \rightarrow H_2O(l)\,;$   $\Delta _rH^o  =-285.8\, kJ\, mol^{-1}$

$CO_2(g) + 2H_2O(l) \rightarrow CH_4(g) + 2O_2(g)\,;$

$\Delta _rH^o  = + 890.3\, kJ\, mol^{-1}$

Based on the above thermochemical equations, the value of, $\Delta _rH^o $ at $298\, K$ for the reaction

$C_{(graphite)} + 2H_2(g) \rightarrow CH_4(g) $ will be for $\Delta_{r} H^{\circ}$ ........... $kJ \,mol^{-1}$

Select the incorrect statement among following

Assertion $A :$ The amphoteric nature of water is explained by using Lewis acid/base concept.

Reason $R$ : Water acts as an acid with $NH _{3}$ and as a base with $H _{2} S$.

In the light of the above statements choose the correct answer from the options given below :