The number of molecules present in 1 dm 3 of hydrogen at S.T.P. is

Question

The number of molecules present in 1 dm 3 of hydrogen at S.T.P. is (A) 1.69 × 1022 (B) 2.69 × 1022 (C) 3.69 × 1022 (D) 1.06 × 1022

Tardigrade Admin · Accepted Answer

We know that 1 mole of H 2 at S.T.P. occupies 22.4 dm 3 and contains 6.023 × 1023 molecules. Therefore 1 dm 3 of hydrogen contains (6.023 × 1023/22.4)=2.69 × 1022 molecules.

Q. The number of molecules present in $1 d m^{3}$ of hydrogen at S.T.P. is

$1.69 \times 1 0^{22}$

$2.69 \times 1 0^{22}$

$3.69 \times 1 0^{22}$

$1.06 \times 1 0^{22}$

We know that $1$ mole of $H_{2}$ at S.T.P. occupies $22.4 d m^{3}$ and contains $6.023 \times 1 0^{23}$ molecules. Therefore $1 d m^{3}$ of hydrogen contains $\frac{6.023 \times 1 0 ^{23}}{22.4} = 2.69 \times 1 0^{22}$ molecules.

Q. The number of molecules present in 1dm3 of hydrogen at S.T.P. is

1.69×1022

2.69×1022

3.69×1022

1.06×1022