Magnesium metal burns in oxygen gas to produce magnesium oxide. How many grams of magnesium oxide will be formed from 16.1 g of oxygen gas? 1. 20.3 g 2. 40.6 g 3. 81.1 g 4. 65.0 g

40.6g

Explanation:

Firstly, we write a balanced chemical equation for the chemical reaction as follows:

2Mg + O2 - -> 2MgO

Theoretically, 2 moles of oxygen gas reacted with 1 mole of magnesium metal to give 2 moles of magnesium oxide.

We now look at what actually happened. From the question, 16.1g of oxygen gas reacted. We need to know the number of moles of oxygen gas in 16.1g of oxygen gas.

Mathematically, the number of moles equals mass divided by molar mass. The molar mass of the oxygen gas is (2 * 16) = 32g/mol. Hence, the number of moles of the oxygen gas reacted is 16.1/32 = 0.503125 moles

Now theoretically, we know that 1 mole of oxygen yielded 2 moles of magnesium oxide, this means 0.503125 mole of oxygen would have yielded 2 * 0.503125 mole of magnesium oxide which equals 1.00625 mole.

Now, we find the mass of magnesium oxide corresponding to this number of moles. We need to know the molar mass of magnesium oxide which is 40.3044g/mol. The mass is given by 1.00625 * 40.3044 = 40.556g