Question

how many oxygen molecules are in a flask that contains 1.43 grams of oxygen?​

Answer 1

Molar mass of Oxygen molecule = 32 g

No. of moles = Given mass / Molar mass

No. of moles = 1.43 / 32

${No. \: of \: moles = 4.46 \times {10}^{ - 2} }$

No. of molecules = No. of moles × Avogadro No.

$\bold{==>4.46 \times {10}^{ - 2} \times 6.022 \times {10}^{23} }$

$\bold{==>2.68581 \times {10}^{ 22} \: is \: the \: answer}$

Hope it helps :)