How much magnesium must be taken to interact with nitric acid if 15 liters of hydrogen is released?

We draw up the reaction equation and place the coefficients: Mg + 2HNO3 = Mg (NO3) 2 + H2.
1) Find the amount of substance hydrogen. To do this, we divide its volume by the molar volume: 15 / 22.4 = 0.67 mol.
2) Find the amount of magnesium substance. According to the reaction equation, there is one mole of magnesium for one mole of hydrogen. This means that the amount of magnesium substance is 0.67 mol.
3) Molar mass of magnesium (according to the periodic table): 24.
4) Find the mass of magnesium. To do this, multiply its molar mass by the amount of substance: 24 * 0.67 = 16.08 g – the answer.