The number of molecules present in 8 g of oxygen gas is …………�

1.	The number of molecules present in 8 g of oxygen gas is …………….(A) 6.022 × 1023(B) 3.011 × 1023 (C) 12.044 × 1023 (D) 1.505 × 1023
Answer» (D) \(1.505 × 10^{23}\) Molar mass of oxygen gas = 32g/mol. \(\therefore \) Number of moles oxygen molecule in \(8g=\frac{8g}{32g/mol}=0.25\) mole \(\therefore \) Number of moles oxygen molecules in 0.25 mole = \(0.25\times6.022\times10^{23}\) = \(1.505\times10^{23}\) oxygen molecule. Option : (D) 1.505 × 10²³

The number of molecules present in 8 g of oxygen gas is …………….(A) 6.022 × 1023(B) 3.011 × 1023 (C) 12.044 × 1023 (D) 1.505 × 1023

Answer»

(D) \(1.505 × 10^{23}\)

Molar mass of oxygen gas = 32g/mol.

\(\therefore \) Number of moles oxygen molecule in \(8g=\frac{8g}{32g/mol}=0.25\) mole

\(\therefore \) Number of moles oxygen molecules in 0.25 mole = \(0.25\times6.022\times10^{23}\)

= \(1.505\times10^{23}\) oxygen molecule.

Option : (D) 1.505 × 10²³