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.