Question

How much pure alkali should be added to 500ml of 10% solution to make the strength 28%

Answer 1

We have to add 90 ml alkali.

• Given data:

Total volume of the solution is 50 mililitres.

Amount of alkali in the initial solution is 10%

Amount of alkali in the final solution is 28%

• At first, we have to calculate the total amount of alkali present in the initial solution

= 500×10/100

= 50 ml

• Now, we have to calculate the total amount of alkali present in the final solution

= 500 ×28/100

= 140 ml

• So, necessary amount of alkali that we have to add in the solution is

= 140-50

= 90 ml

We have to add 90 mililitres of alkali in the solution to make the strength of the solution 28% . (Answer)

Answer 2

Answer:

90ml

Step-by-step explanation:

total amount of solution= 500ml

the amount of initial solution= 10%

total amount of solution= 28%

500ml of 10% solution= 500×10/100

= 50ml

500ml of 28% solution= 500×28/100

= 140ml

the amount of pure alkali= 140-50 =90ml