Question

A person requires $10000kJ$ energy per day and $∆H$ combustion of glucose is $2700kJmo{l}^{-1}$. How many grams of glucose are required by the body in a day?

• A. $666.67g$
• B. $6.67g$
• C. $66.67g$
• D. $6666.67g$

Answer 1

The correct option is A

$666.67g$

The explanation for the correct answer is,

Step 1. Given Data:

The Energy required = $10000\raisebox{1ex}{$kJ$}\!\left/ \!\raisebox{-1ex}{$day$}\right.$

Combustion of glucose = $2700kJmo{l}^{-1}$

Step 2. As we know.

The molar mass of glucose, $\left(C_6{H}_{12}{O}_6\right)=180\raisebox{1ex}{$g$}\!\left/ \!\raisebox{-1ex}{$mol$}\right.$

Moles of glucose required per day:

$\begin{array}{l}\Rightarrow \frac{1000{\displaystyle \raisebox{1ex}{$kJ$}\!\left/ \!\raisebox{-1ex}{$day$}\right.}}{2700{\displaystyle \raisebox{1ex}{$kJ$}\!\left/ \!\raisebox{-1ex}{$day$}\right.}}=\frac{100}{27}\raisebox{1ex}{$mol$}\!\left/ \!\raisebox{-1ex}{$day$}\right.\end{array}$

Grams of glucose required by the body in a day:

$\Rightarrow \begin{array}{l}\frac{100}{27}\times 180\left(\frac{g}{day}\right)=666.67\raisebox{1ex}{$g$}\!\left/ \!\raisebox{-1ex}{$day$}\right.\end{array}$

Hence, the correct option is (A).