Question

What is the percent of MAGNESIUM in magnesium oxide if there are 16.0 grams of oxygen in 42 grams of magnesium oxide?

a) 38.1%
b) 61.9%
c) 71.4%
d) 28.6%

Answer 1

The percent of magnesium in magnesium oxide is b) 61.9%.

Step-by-step explanation:

To determine the percent of magnesium in magnesium oxide, we need to calculate the masses of magnesium and oxygen in the compound.

Given that there are 16.0 grams of oxygen in 42 grams of magnesium oxide, we can subtract the mass of oxygen from the total mass of magnesium oxide to find the mass of magnesium.

Mass of magnesium = Total mass of magnesium oxide - Mass of oxygen = 42 g - 16.0 g = 26.0 g

The percent of magnesium in magnesium oxide can be calculated using the formula:

Percent composition = (mass of magnesium / total mass of magnesium oxide) * 100%

Percent composition = (26.0 g / 42 g) * 100% = 61.9%