What is the mass of 2.4 * 1023 molecules of NO2? 12 g 1.2 * 102 g 75 g 1.1 * 1023 g 18 g

As we know,

1 mole of any substance contains 6.022 * 10²³ particles. And 1 mole of NO₂ (equal to 46 g) contains 6.022 * 10²³ Molecules. Hence,

6.022 * 10²³ Molecules of NO₂ = 46 g

So,

2.4 * 10²³ Molecules of NO₂ = X g

Solving for X,

X = (2.4 * 10²³ Molecules * 46 g) : 6.022 * 10²³ Molecules

X = 18.33 g