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lursa
calculate the mass in kilograms of 6.7x10^21 molecules of NO2
You need to use Avogadro's number 6.0221415 × 10^23 which explains how many molecules go per mole, and then you just need to calculate the molecular weight of NO2 (just combine the molecular weight of one N atom and two O atoms) so the calculus is: x molecules of NO2 * 6.0221415 × 10^23 molecules/mole = x moles of NO2 x moles of NO2 * molecular weight of NO2 (g/mole) = x g of NO2