Question

100 mL, 2 M KOH solution is mixed with 400 ml of 5 M KOH solution. The molarity of resultant solution becomes​

Answer 1

molarity is 4.4 milli molar

Answer 2

Given info : 100 mL, 2 M KOH solution is mixed with 400 ml of 5 M KOH solution.

To find : The molarity of resultant solution becomes ..

solution : 100 ml, 2 M KOH solution

no of moles of KOH = volume of solution In L × molarity

= 100/1000 L × 2 M

= 0.2 mol

400 ml, 5 M KOH solution

no of moles of KOH = 400/1000 L × 5 M

= 0.4 × 5 = 2 mol

after mixing,

total no of moles of KOH = 0.2 + 2 = 2.2 moles

total volume of solution = 100 ml + 400 ml = 500 ml

now molarity of the resultant solution = total no of moles of KOH/total volume of solution in L

= 2.2 mol/(500/1000 L)

= 4.4 M

Therefore the molarity of the resultant solution is 4.4 M.