Question

volume of water required to be dissolved in 400ml at 0.5m naoh solution to prepare a decimolar solution

Answer 1

Given:

Volume of NaOH = 500 mL

Molarity of the aqueous solution = 0.5 M

Molar mass of NaOH= (23+16+1)g = 40g

Let the mass of NaOH be x.

Now , according to formula number of moles of a given substance = given mass/molar mass

Therefore, no. Of moles of NaOH= x/40

Since, molarity = number of moles of solute/ volume of solution in lit.

Hence, 0.5 = (x/40)/(500/1000)

Solving this we get x= 10g

Hence, 10g of NaOH should be taken to obtain a 0.5 M solution of volume 500 mL.

I hope I could explain the numerical well and help you.