Question

1. what is the percent composition of magnesium (mg) in mgbr₂?

0.132 % mg
23.32 % mg
13.20 % mg
184 % mg
clear all

Explanation:

Step1: Find molar masses

Molar mass of Mg: $24.31\ g/mol$.
Molar mass of Br: $79.90\ g/mol$, so for $Br_2$: $2\times79.90 = 159.80\ g/mol$.

Step2: Calculate molar mass of $MgBr_2$

Molar mass of $MgBr_2$ = $24.31 + 159.80 = 184.11\ g/mol$.

Step3: Calculate percent composition of Mg

Percent composition = $\frac{\text{Molar mass of Mg}}{\text{Molar mass of } MgBr_2} \times 100\%$
= $\frac{24.31}{184.11} \times 100\% \approx 13.20\%$.

Answer:

13.20 % Mg (corresponding to the option "13.20 % Mg")