A person takes 15 breaths per minute. The volume of air inhaled in each breath is 448 ml and contains 21% of oxygen by volume. The exhaled air contains 16% of oxygen by volume. If all the oxygen is used in the combustion of sucrose, how much of the Sucrose is burnt in the body per day & how much heat is evolved. `Delta H_(com)` of sucrose is `= 6000 kJ mol^(-1)`. Take temperature to be 300 K throughout. [Assuming `V_("inhaled air") = V_("exhalded air"), P_(atm) = 1atm`]

Answer

9.822 MJ/day evolved, 560 gm

Explanation

Oxygen inhaled `=21/100xx448=94.08`
Exhaled air `=16/100xx448=71.68`
Oxygen used `=22.4 ml` (In one breath)
Total oxygen in a day `=22.4 mL` (in one breath)
Total oxygen used in a day `=22.4xx15xx60xx24=483840 mL =483.84 L`
Apply `PV=nRT`
`n=19.644`
Moles of sucrode used `=1/12xx19.644=1.637`
Total energy evolved `=1.637xx6000=9822 kJ`