Question

1.5 mol of $O_2$ combine with Mg to form oxide MgO. The mass of Mg (at. mass 24) that has combined is

• A. 72 g
• B. 36 g
• C. 48 g
• D. 24 g

Answer 1

Answer: (A)

72 g

Answer 2

$\underset{\text{48 g}}{ {2 Mg}}+\underset{\text{1 mol}}{ {O_{2}}}\to 2MgO$ Thus, $1.5$ mol of $O_{2}$ combine with $Mg$ $=48 \times 1.5\,g$ $=72\,g$