Processing math: 100%


1)

5.0 g of sodium hydroxide(molar mass 40 g mol1 ) is dissolved in little quantity of water and the solution is diluted up to  100mL. what is the molarity of the resulting solution?


A) 0.1 mol dm3

B) 1.0 mol dm3

C) 0.125 mol dm3

D) 1.25 mol dm3

Answer:

Option D

Explanation:

 Given, W (mass of solute) =5.0 g

 m (molar mass of solute)=40 g mol-1

 Volume=100 mL

 Molarity  is given as,

 M= Moles of solute/ Volume of solution (in L)

M= W x 1000/  m x volume  of solution (in mL)

  =5.0g×100040×100

 =1.25 mol dm3