Question

An athlete is given $100g$ of glucose $\left(C_6{H}_{12}{O}_6\right)$ of energy equivalent to $1560kJ$. He utilises $50\%$ of this gained
energy in the event. In order to avoid storage of energy in the body, calculate the weight of water he would need to perspire.
The enthalpy of evaporation of water is $44kJ/mol$

• A. 319 gm
• B. 200 gm
• C. 100 gm
• D. None of these

Answer 1

The correct option is A 319 gm

Energy supplied to athlete by consuming $100gofglucose=1560kJ$
Energy utilised in event =$\frac{50}{100}\times 1560$
$=780kJ$
$\therefore$ Energy left as excess in body =$1560-780$
$=780kJ$
$44kJ$ energy is required to evaporate = $18g{H}_{2}O$
$\therefore 780kJ$ energy used to evaporate = $\frac{18\times 780}{44}$ of $H_{2}O$
$=319.09g$
Thus, athlete should perspire $319.09g$ of $H_{2}O$ in order to avoid storage of energy in body.