# Arun has prepared 0.01% (by mass) solution of sodium chloride in water. Which of the following correctly represents the composition of the solutions? (a) 1.00 g of NaCl + 100g of water (b) 0.11g of NaCl + 100g of water (c) 0.0l g of NaCl + 99.99g of water (d) 0.10 g of NaCl + 99.90g of water

Answer: (c) 0.0l g of NaCl + 99.99g of water

Here,

$$Mass\, percentage = \frac{Mass\, of\, solute\times 100}{Mass\, of\, solute + Mass\, of\, solvent}$$

(a) 1.00 g of NaCl + 100g of water

$$Mass\, percentage = \frac{1.00}{1.00 + 100}\times 100$$

Mass % = 0.99 %

(b) 0.11g of NaCl + 100g of water

$$Mass\, percentage = \frac{0.11}{0.11 + 100}\times 100$$

Mass % = 0.1098 %

(c) 0.01 g of NaCl + 99.99g of water

$$Mass\, percentage = \frac{0.01}{0.01 + 99.99}\times 100$$

Mass % = 0.01 %

(d) 0.10 g of NaCl + 99.90g of water

$$Mass\, percentage = \frac{0.10}{0.10 + 99.90}\times 100$$

Mass % = 0.1 %