How many grams of KBr are needed to create 750.0 mL of solution with a molar mass of 0.0552M KBr 119.00gmol? To calculate the number of moles required, multiply the molarity (M, which is measured in mol/L) by the volume (in L). Then multiply the result by the molar mass. When you look at the units, they will cancel out to give you a result in grams. mol/L*(L)=mol, mol*(g/mol)=g As a result, the numerical solution is (0.0552 mol/L)*(0.750 L)*(119.00 g/mol)= 4.93 g KBr.
