Question

Find
the
molarity of 20%
20% w/v
NaOH solution​

Answer 1

Answer:

A 20% weight by volume, or (w/v), solution of NaOH is 20g of NaOH per 100 ml.

The definition of molarity is moles per litre, so we need to work out how many moles we have in 1 litre, and for this, we need the molecular weight of NaOH, which is 39.997 g/mol.

So, in 100 ml we have 20 g of NaOH.

Therefore, in 1000 ml (1 litre) we have 20 x 10 = 200 g

As the molecular weight of NaOH is 39.997 g/mol, then we have 200/39.997 = 5.000375028 moles, so we will call that 5 moles.

These 5 moles are in 1 litre, so we have a 5 Molar solution.

Explanation:

Hope it helps