Question

Total number of neutrons present in 4gm of heavy water

Answer 1

Step 1:

Given mass = 4g, Molar mass of D2O=4+16=20g
No of moles = Givenmassmolarmass=420=0.2mole
No of molecules =( Mole × Avogadro number )
= 0.2 × 6.022 × 10²³=1.2044×10²³

Step 2:
No of neutrons in one molecule of D2O = (2 ×1 + 8) = 10
No of neutrons in 1.2044×1023 of D2O = 1.2044×10²³×10=1.2044×10²⁴