Question

Pehal and Ishaan were making 100g of sugar solutions with concentration by mass 20% and 50% respectively.Pehal added 20g of sugar in her solution whereas Ishan evaporated 20g of water from his solution. Now, the two solution were mixed to form a final solution. The concentration by mass of final solution is what

Answer 1

the concentration of mass of final solution is 45%. see the attachment for the steps. pls mark as brainliest

Answer 2

Answer: Concentration by mass of the final solution is 45%

Explanation: Mass percent is fined as the mass of the component present in a 100 grams of solution multiplied by 100.

Mathematically,

$\text{mass }\%=\frac{\text{Mass of the component (in grams)}}{\text{mass of the solution}}\times 100$     ....(1)

Case 1 : When Pehal and Ishaan made 20% and 50% sugar solutions

Pehal: She made 20% sugar solution which means that 20 g of solution is present in 100 g of solution.

Mass of water = 100 - 20 = 80g

Ishaan: He made 50% sugar solution which means that 50 g of sugar is present in 100 g of solution.

Mass of water = 100 - 50 = 50g

Case 2: Both did some changes

Pehal: Now, she added 20 g of sugar.

Mass of sugar = 20 + 20 = 40g

Mass of water = 80g (remains same as in case 1)

Mass of solution = 80 + 40 = 120g

Ishaan: Now, he evaporated 20g of water.

Mass of sugar = 50g  (remains same as in case 1)

Mass of water = 50 - 20 = 30g

Mass of solution = 50 + 30 = 80g

Case 3: After mixing both the solutions

Total Mass of the solution = 120 + 80 = 200g

Total Mass of the sugar = 40 + 50 = 90g

Putting the values in equation 1, we get

$\text{Mass }\%=\frac{90}{200}\times 100$

Mass percent of the final solution = 45%