Answer to Question #56105 in Inorganic Chemistry for Jasmine

Question

The number of atoms in 22g of strontium is z. What is the number of bromine molecules in 20g of bromine gas ?

Answer 1

MWSr = 87.62 g/mol
MWBr2 = 159.808 g/mol

n = N/N_A = m/MW;
N = m N_A/MW
N(Sr)/N(Br2) = (m(Sr) N_A/MW(Sr))/(m(Br₂) N_A/MW(Br₂)) = m(Sr) MW(Br₂)/m(Br₂) MW(Sr) = (22 g 159.808 g/mol)/(20 g 87.62 g/mol) = 2.0

N(Br₂) = 0.5 N(Sr) = 0.5 z