What mass of lithium hydroxide is formed when 1.4 g of lithium reacts with water?

2Li + 2H2O = 2LiOH + H2.
1) According to the periodic table, we determine the molar mass of lithium: 7.
2) Find the amount of lithium substance. For this, the mass of lithium is divided by its molar mass: 1.4 / 7 = 0.2 mol.
3) According to the reaction equation, there are two moles of lithium hydroxide for two moles of lithium. This means that the amount of lithium hydroxide substance is: 0.2 mol.
4) Find the molar mass of lithium hydroxide: 7 + 16 + 1 = 24.
5) Calculate the mass of lithium hydroxide. For this, the amount of lithium substance is multiplied by its molar mass: 0.2 * 24 = 4.8 g – the answer.