Question

Calculate number of molecules present in 1Kg of oxygen

Answer 1

Explanation:

According to Avogadro, there are $6.023 \times 10^{23}$ molecules or atoms present in 1 mole of a substance.

Molar mass of oxygen atom is 32 g/mol.

Also, it is known that number of moles = $\frac{mass}{molar mass}$

                                                       = $\frac{1000 g}{32}$

                                                       = 31.25 mol

Hence, number of molecules present in 1 Kg of oxygen are as follows.

                         = $6.023 \times 10^{23} \times 31.25$

                         = $188.21 \ 10^{23}$ molecules

Therefore, we can conclude that there are $188.21 \ 10^{23}$ molecules in 1 Kg of oxygen.