Given, …; … = - 393.5 kJ mol⁻¹ … + …\to {{\rm H}_2}{\rm O}(l)…{\Delta _r}{H^o}…C{O_2}(g)…2{{\rm H}_2}{\rm O}(l) \to…C{H_4}(g)…2{O_2}(g)…{\Delta _r}{H^o}…{\Delta _r}{H^o}…{C_{(graphite)}}…2{{\rm H}_2}(g) \to…C{H_4}(g)… will be :

Option B. C(graphite) + O₂(g) … CO₂ (g);

Thermodynamics

JEE Main 2017 · Session, Shift 1 · Q2349

ChemistryHard84×since 2002Q2349

Given,

{C_{(graphite)}} + {O_2} \to C{O_2}(g)

;

{\Delta _r}{H^o}

= - 393.5 kJ mol⁻¹

{{\rm H}_2}(g)

{1 \over 2}{O_2}(g)

\to {{\rm H}_2}{\rm O}(l)

{\Delta _r}{H^o}

= - 285.8 kJ mol⁻¹

C{O_2}(g)

2{{\rm H}_2}{\rm O}(l) \to

C{H_4}(g)

2{O_2}(g)

{\Delta _r}{H^o}

= + 890.3 kJ mol⁻¹ Based on the above thermochemical equations, the value of

{\Delta _r}{H^o}

at 298 K for the reaction

{C_{(graphite)}}

2{{\rm H}_2}(g) \to

C{H_4}(g)

will be :

Thermodynamics — JEE Main 2017 · Session, Shift 1 · Q2349 · Alror