Question

2. If you consume 5 grams each of water and chalk, will you consume more water molecules or more chalk molecules? Explain.
3. If you consume 5 moles each of water and chalk, will you consume more water molecules or more chalk molecules? Explain.

Answer 1

1. One mole of substance consists of $6.022*10^{23}$ molecules.

Molar mass CaCO₃ = 100g/mol

5g = 5/100 = 0.05mol

No of molecules: $0.05*6.022*10^{23} = 3.011*10^{22}$ molecules

Molar mass H₂O = 18g/mol

5g = 5/18 = 0.278mol

No. of molecules = $0.278*6.022*10^{23} = 1.67*10^{23}$ molecules

Answer: with 5g water you consume more molecules.

2. The number of molecules is the same, because one mole of substance consists of $6.022*10^{23}$ molecules.