Question
Give the number of molecules is 2 g hydrogen. [Ans. 6.022 × 1023]
Answer
Step 1: Calculation of Molar mass
The molar mass of hydrogen (H2) = 2 × 1 = 2
Step 2: Calculation of number of moles
Number of moles of hydrogen = Mass\ of\ hydrogen \over Molar\ mass\ of\ hydrogen
= 2\over2 = 1
Step 3: Calculation of number of molecules
Number of molecules of hydrogen = Number of moles of hydrogen × Avogadro’s number
= 1 × 6.022 × 1023
= 6.022 × 1023 molecules