Question

1. find the percent composition of both elements in hbr.

Explanation:

Step1: Calculate molar mass of HBr

Molar mass of H = 1.008 g/mol, Br = 79.904 g/mol.
Molar mass of HBr = $1.008 + 79.904 = 80.912$ g/mol.

Step2: Find % composition of H

$\% H = \frac{\text{mass of H}}{\text{molar mass of HBr}} \times 100 = \frac{1.008}{80.912} \times 100 \approx 1.25\%$

Step3: Find % composition of Br

$\% Br = \frac{\text{mass of Br}}{\text{molar mass of HBr}} \times 100 = \frac{79.904}{80.912} \times 100 \approx 98.75\%$

Answer:

Percent composition of H: ~1.25%, Percent composition of Br: ~98.75%