Sulphuric acid used in Lead Storage battery has a concentration of 4.5 ~M and a density of 1.28 ~g / ~ml . The molality of the acid is __________.

Step-by-step solution

Given molarity M = 4.5 mol/L and density d = 1.28 g/mL . The mass of 1 L of solution is 1000 mL 1.28 g/mL = 1280 g . The mass of solute ( H₂SO₄ ) in 1 L of solution is 4.5 mol 98 g/mol = 441 g . The mass of solvent (water) is 1280 g - 441 g = 839 g = 0.839 kg . Molality m = moles of solute mass of solvent in kg = 4.5 0.839 5.3635 m . Rounding to three decimal places, the molality is 5.364 m . Answer: 5.364