One mole of bromine gas, Br2, has a mass of(1) 35.0 g (3) 79.9 g (2) 70.0 g (4) 159.8 g

NY Regents Chemistry Exam Jan 2023

One mole of bromine gas, Br2, has a mass of (1) 35.0 g

(2) 70.0 g

(3) 79.9 g

(4) 159.8 g

Solution: Gram formula mass (or molar mass) gives us the number of grams per 1 mol of compound.

Looking at the Periodic Table, bromine has mass of 79.904g per mol of Br.

Br2 mass would be: 2* 79.904g = 159.8 g which is the correct answer choice 4.