Question

0.98g of H2s04 is dissolved in 100ml solution. What is the molarity of solution?

Answer 1

Molarity = (number of moles of solute / volume of solution in liters) 

Here number of moles = ( given mass of solute / molar mass ) 

whereas Normality = ( Number of gram equivalent / volume of solution in liter ) 

where gram equivalent = ( mass of solute / equivalent mass ) 

Consider an example of H2SO4 whose molar mass = 98 g per mole 

Consider a Solution containing 0.98 g of sulphuric acid in 100 mL. 

Volume = 100 ml = 0.1 L 

Then, 

Number of moles = 0.98 / 98 

Number of moles = 0.01 

Hence molarity = 0.01 / 0.1 = 0.1 M 

Hence Molarity = 0.1 M 

Now sulphuric acid is dibasic therefore 

its equivalent weight = 98 / 2 

Hence equivalent weight = 49 

so the gram equivalent = 0.98 / 49 = 0.02 

Now Normality = 0.02 / 0.1 

Hence the Normality is equal to 0.2 N. 

Thus For H2SO4 ( i.e. dibasic ) Normality is 0.2 N and molarity is 0.1M.

Answer 2

0.1 is the molarity. It's very easy