Answer:
Percentage composition H in HBr = 1.236%
Percentage composition Br in HBr = 98.764%
Explanation:
H = 1g/mol
Br = 79.904g/mol
HBr = Molar Mass 80.904 g/mol
Percentage composition of X = (X / Molar Mass) x 100
H = (1/80.904) x 100 = 1.236%
Br = (79.904/80.904) x 100 = 98.764%