# human body contains 60% water, number of water molecules in a body with mass of 60kg is:?

A. 3.01*10^24

B. 1.20*10^27

C. 6.02*10^26

D.1.20*10^24

plz explain also

### 4 Answers

- 8 years ago
Mass of water = 60 * 60 / 100 = 36 kg = 36000 g

number of moles = Mass / Molar mass = Number of molecules / Avogadro Constant

Thus, Number of molecules = (36000/18) * 6.022 * 10^23 (Molar mass of water = 1*2 + 16 = 18)

= 12.044 * 10^26

This can be approximated to 1.20 * 10^27

Hence, answer is (B) 1.20*10^27 .

- Anonymous8 years ago
60% of 60kg is 36 kg

1 liter of water is equal to 1000 milliliters or 1000 grams (1 ml = 1 g). The molecular mass of water is 18, so the number of moles in 1 L of water is given by the equation:

1000 grams * (1 mol water / 18 MM) = 55.5 moles

Multiplying this number by 6.02 *10^23 gives 3.34 * 10 ^25

now this is for 1kg there fore for 36kg

120.2 *10^25 which is 1.20*10^27, B

- 8 years ago
B.1.20*10^27

percentage=mass of water* molecules of water*100/60*10^3

molecules of water=60*60*10^3/100*18

molecules of water=2000

number of molecules of water=2000*6.02*10^23

number of molecules of water=1.20*10^27