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Standard XII

Chemistry

Sucrose

A person inha...

Question

A person inhales 960 g of $O_{2}$ per day. Assume that all the $O_{2}$ is used for converting sugar into $C O_{2}$ and $H_{2} O$ . Calculate the heat evolved.
( $Δ H$ combustion of sucrose = - 5645 kJ/mol)

14112.5 kJ

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855 kJ

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5645 kJ

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Solution

The correct option is A 14112.5 kJ
The equation for combustion of sucrose is:
$C_{12} H_{22} O_{11} + 12 O_{2} \to 12 C O_{2} + 11 H_{2} O; Δ H = - 5645$ kJ
Moles of $O_{2}$ used per day $= \frac{W e i g h t o f O_{2}}{M o l e c u l a r m a s s o f O_{2}}$
$= \frac{960}{32} = 30$ mol
From Equation,
because 12 mol of $O_{2}$ is used for combustion of 1 mol of $C_{12} H_{22} O_{11}$
$∴$ 30 mol of $O_{2}$ is used for combustion of $\frac{1}{12} \times 30 C_{12} H_{22} O_{11}$
=2.5 mol $C_{12} H_{22} O_{11}$
$∵$ Weight of 1 mol $C_{12} H_{22} O_{11} = 342$ g
$∴$ 2.5 mol $C_{12} H_{22} O_{11} = 2.5 \times 342 = 855$ g
On combustion of 342 g of $C_{12} H_{22} O_{11} 5645$ kJ heat is evolved.
$∴$ On combustion of 855 g of $C_{12} H_{22} O_{11}$ $\frac{5645}{342} \times 855 = 14112.5$ kJ.

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A person inhales 960 g of O2 per day. Assume that all the O2 is used for converting sugar into CO2 and H2O. Calculate the heat evolved. (ΔH combustion of sucrose = - 5645 kJ/mol)

A person inhales 960 g of $O_{2}$ per day. Assume that all the $O_{2}$ is used for converting sugar into $C O_{2}$ and $H_{2} O$ . Calculate the heat evolved.
( $Δ H$ combustion of sucrose = - 5645 kJ/mol)