Question

How many molecules are in 12.8 g N2O4

Answer 1

N2O4 has a molar mass of 14*2+16*4 = 92 g/mol12.8/92=0.139 mol0.139 * avogadro's number = 8.37*10^22 molecules.

Answer 2

To calculate number of molecules, we first need to calculate the number of moles of N₂O₄.

Number of moles of N₂O₄ = \frac{Given mass}{Molar mass of N₂O₄}

Molar mass of N₂O₄= 92 g/mol

Given mass of N₂O₄= 12.8 g

Number of moles of N₂O₄=\frac{Given mass}{Molar mass of methane}

=\frac{12.8}{92}

= 0.139 mol

Number of molecules of N₂O₄ = 0.139\times 6.023 \times 10^{23}

= 8.37 × e²²