How many molecules are in 12.8 g N2O4

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.

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