Question

You accidentally added 50 ml of distilled water to 33 ml of a 50 % (m/v) sucrose solution. what is the molarity of the diluted solution

Answer 1

we are given a 50% (m/v) solution of sucrose and initial volume = 33 ml

It implies mass of sucrose in this solution = (50×33 ) / 100 = 16.5 grams

∴ moles of sucrose in solution = mass of sucrose / molar mass of sucrose

                                                   = 16.5 g÷ (342.3 g/mol) = 0.0482 moles

Now after accidentally adding water only the volume of solution changes but the moles of sucrose remains same.

Thus, new volume = 33 ml + 50 ml = 83 ml = 0.083 L

we know, molarity is defined as number of moles of solute per volume of solution in L.

∴ Molarity of new solution = 0.0482 moles ÷ 0.083 L

                                            = 0.5807 M

Ans- 0.5807 M