Question

During an experiment the students were asked to prepare a 5% (mass/mass) solution of potassium chloride in water. Which of the following correctly represents the composition of the solution? 5g of KCl + 100 g of water В. 5g of KCl + 95 g of water C. 0.5 g of KCl + 99.95 g of water g D. 0.05 g of KCl + 100 g of water​

Answer 1

Answer:

During an experiment, the students were asked to prepare a 10% solution of sugar in water. Ramesh dissolved 10g of sugar in 100g of water while Sarika prepared it by dissolving 10g of sugar in water to make 100g of the solution.

Answer 2

A $\frac{m}{m} \%$ expresses concentration terms in the mass of both the solute and the solution.

It is calculated by using the formula:

$\\ \frac{m}{m}\% =\frac{mass\ of \ solute}{mass\ of \ solution} \times 100$

a) A $\frac{m}{m} \%$ representation of 5g of KCl + 100 g of water:

$\frac{m}{m} \% = \frac{5}{105} \times 100= 4.76\%$

b)A $\frac{m}{m} \%$ representation of 5g of KCl + 95 g of water:

$\frac{m}{m} \% = \frac{5}{100} \times 100= 5\%$

c) A $\frac{m}{m} \%$ representation of 0.5 g of KCl + 99.95 g of water:

$\frac{m}{m} \% = \frac{0.5}{100.45} \times 100= 0.49\%$

d)A $\frac{m}{m} \%$ representation of 0.05 g of KCl + 100 g of water​:

$\frac{m}{m} \% = \frac{0.05}{100.05} \times 100= 0.049\%$

Hence, the correct option is  В) 5g of KCl + 95 g of water.