Question

7.45 g of potassium chloride is dissolved in 100g of water what will be the molarity of the solution

Answer 1

Given the mass of potassium chloride is  7.45 grams

Calculating the moles form the mass and molar mass of KCl :

$7.45g *\frac{1mol }{74.6g}=0.100mol$

Total mass of the solution = Mass of KCl + Mass of water

                                            = 7.45 g + 100 g = 107.45 g

Assume the density of solution = 1 g/mL

Volume of solution = $107.45g*\frac{1mL}{1g} =107.45mL$

Molarity of the solution can be calculated from moles of KCl and volume of solution as follows,

$\frac{0.100mol}{107.45mL} *\frac{1000mL}{1L} =0.931mol/L$