Pehal and Ishaan were making 100 g sugar solutionswith concentration b

1.	Pehal and Ishaan were making 100 g sugar solutionswith concentration by mass 20% and 50%respectively. Pehal added 20 g of sugar in hersolution whereas Ishaan evaporated 20 g of waterfrom his solution. Now, the two solutions were mixedto form a final solution. The concentration by massof final solution is(1) 28%(3) 40%(2) 45%(4) 60%
Answer» 1 Secondary School In case of Pehal, 20% of sugar solution in which she added 20 g of sugar more. Mass of sugar before addition to the solution = 20 g Mass of sugar after addition to the solution = 20 +20 = 40 g Mass of water in solution= 80 g = Total mass of solution= 80 g + 40 g = 120 g In case of Ishaan, 50% of sugar solution from which he evaporated 20 g of water. Mass of sugar in solution = 50 g Mass of water before evaporation= 50 g Mass of water after evaporation = 50 g - 20 g = 30 g = Total mass of solution=50 g + 30 g = 80 g After mixing both the solution Total mass of sugar after the mixing of solutions,(M) = 40 g + 50 g = 90 g Total mass of the final solution= =120 g + 80 g = 200 g Mass percentage of sugar in final solution= The concentration by mass of final solution is 45%

Pehal and Ishaan were making 100 g sugar solutionswith concentration by mass 20% and 50%respectively. Pehal added 20 g of sugar in hersolution whereas Ishaan evaporated 20 g of waterfrom his solution. Now, the two solutions were mixedto form a final solution. The concentration by massof final solution is(1) 28%(3) 40%(2) 45%(4) 60%

Answer»

Secondary School

In case of Pehal, 20% of sugar solution in which she added 20 g of sugar more.

Mass of sugar before addition to the solution = 20 g

Mass of sugar after addition to the solution = 20 +20 = 40 g

Mass of water in solution= 80 g

= Total mass of solution= 80 g + 40 g = 120 g

In case of Ishaan, 50% of sugar solution from which he evaporated 20 g of water.

Mass of sugar in solution = 50 g

Mass of water before evaporation= 50 g

Mass of water after evaporation = 50 g - 20 g = 30 g

= Total mass of solution=50 g + 30 g = 80 g

After mixing both the solution

Total mass of sugar after the mixing of solutions,(M) = 40 g + 50 g = 90 g

Total mass of the final solution= =120 g + 80 g = 200 g

Mass percentage of sugar in final solution=

The concentration by mass of final solution is 45%