Question

A vessel contains 30 litres of 60% nitric acid. How much water should be added to the vessel
so that the concentration of acid becomes 40%?​

Answer 1

Answer:

simple way

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focus on the water which has to increase from 30% to 60%

so total quantity has to increase to (60/40)*30 L = 45 L

and water to be *added* = 45-30 = 15 L

Answer 2

Answer:

15 Litres of water

Step-by-step explanation:

Concentration = number of moles per volume

Number of moles of Nitric acid in 30 Litres:

30*0.6=18

and after mixing, concentration = 40%= 0.4

so, volume = 18/0.4=45 Litres

so, water to be added is 45-30= 15 Litres