MCQ
Which of the following has most density
- A$Fe$
- B$Cu$
- C$B$
- ✓$Pb$
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${H_2}O\left( g \right) + C\left( s \right) \to CO\left( g \right) + {H_2}\left( g \right);\Delta H = 131\,kJ$
$CO\left( g \right) + \frac{1}{2}{O_2}\left( s \right) \to C{O_2}\left( g \right);\Delta H = - 282\,kJ$
${H_2}\left( g \right) + \frac{1}{2}{O_2}\left( s \right) \to {H_2}O\left( g \right);\Delta H = - 242\,kJ$
$C(s) + O_2(g) \to CO_2(g); \Delta H = X\,kJ$
The value of $X$ will be......$kJ$
(Use $\mathrm{R}=0.083 \mathrm{~L}$ bar mol $\mathrm{m}^{-1} \mathrm{~K}^{-1}$ )
