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 + 100 g of water
(b) 0.11 g of NaCl + 100 g water
(c) 0.01 g of NaCl + 99.99 g of water
(d) 0.10 g of NaCl + 99.90 g of water

Explanation

Here mass % `=("mass of solute"xx100)/("mass of solute"+"mass of solvent")`
`=(0.01gxx100)/((0.01+99.99)g)=(0.01xx100)/(100.00)=0.01%`
Which is equal to the percentage of sodium chloride in water prepared by Arun. So, option (c) is correct.
In option(a), mass% `=(1.00gxx100)/((1.00+100)g)=(1.00xx100)/(101.00)=0.99%`
In option(b), mass%`=(0.11gxx100)/((0.11+100)g)=(11)/(100.11)=0.11%`
In option(d), mass% `=(0.1gxx100)/((0.1+99.90)g)=(10)/(100)=0.1%`
These % are not equal to the % of sodium chloride solution in water prepared by Arun. So, these are incorrect.