Question

A solution is prepared by dissolving 5.6 g of KOH is 250 ml of it. Calculate the molarity of the solution?(molar mass KOH: 56 g/ mol) [Ans. : 419M]

Answer 1

`c = "0.40 mol/L"`

Explanation:

The formula for molar concentration `c` is

`c = "moles"/"litres"`

`"Moles" = 5.6 color(red)(cancel(color(black)("g KOH"))) × "1 mol KOH"/(56.11 color(red)(cancel(color(black)("g KOH")))) = "0.0998 mol KOH"`

`"Litres" = 250 "mL" × "1 L"/(1000 "mL") = "0.2500 L"`

`c = "0.0998 mol"/"0.2500 L" = "0.40 mol/L"`