Is 2 liters of oxygen enough to burn 2 grams of magnesium?

To answer this question, you need to calculate the amount of oxygen sufficient to burn a sample of magnesium. Magnesium in oxygen burns to yield MgO oxide.

Reaction equation:

2 Mg + O2 = 2 MgO

Molar mass of magnesium oxide = 40 g / mol; molar volume of oxygen = 22.4 l / mol (according to Avogadro’s law). Let’s make the proportion according to the equation:

X l. oxygen corresponds to 2 g of magnesium, as

40 g / mol corresponds to 2 * 22.4 L / mol of oxygen.

X = (2 * 40) / (2 * 22.4) = 1.79 liters.

To burn 2 g of magnesium, 1.79 liters of oxygen are needed. 1.79 l. <2 liters, then the indicated volume of oxygen is sufficient.

Answer: 2 liters of oxygen is enough to burn 2 g of magnesium.