Express the quantity in moles to three significant figures.

Question

In the gaseous state, chlorine exists as a diatomic molecule Cl2 (Molar mass = 70.9 g/mol). Calculate the number of moles of chlorine present in 120 g of chlorine gas.

Answer 1

Hey Anya,

For this question, we know that the molar mass of Cl2 is 70.9 g/mol. To go from 120 g of Cl2 to moles of Cl2, we convert by dividing our grams of Cl2 by the molar mass of Cl2.

120 g Cl2 * 1 mol Cl2/ 70.9 g Cl2= 1.69 mol Cl2

Hope this helps!