The most abundant elements by mass in the body of a healthy human adult are: Oxygen (61.4%), Carbon (22.9%), Hydrogen (10.0%), and Nitrogen (2.6%). The weight which a 75 kg person would gain if all `.^(1)H` atoms are replaced by `.^(2)H` atoms is:

Options

A. 15 kg
B. 37.5 kg
C. 7.5 kg
D. 10 kg

Answer

C

Explanation

Percentage (by mass) of elements given in the body of a healthy human adult is :-
Oxygen=61.4%, Carbon=22.9%,
Hydrogen=10.0% and Nitrogen = 2.6%
`:.` Weight of person = 75 kg
`:. "Mass due to" ""^(1)H "is" = 75 xx (10)/(100)= 7.5 kg`
If `""^(1)H` atoms are replaced by `""^(2)H` atoms, mass gain by person would be = 7.5 kg