How many grams of KCl are needed to make 3.0 L of a 3.4 M solution?

In a 3.4 M solution, there are 3.4 moles per liter. If you want to make 3 liters of solution, you'll need 3 liter * 3.4 moles/liter = 10.2 moles The molar mass of KCl is 39.098 g/mole K + 35.453 g/mole Cl = 74.551 g/mole KCl To get the number of grams, multiply the number of moles by the molar mass: 10.2 moles * 74.551 g/mole KCl = 760.4202 g = 0.760 kg