Question

What is the strength (in ppm) of 0.500 g NaCl dissolved in 1.06 L of water (Density = 1.000 kg/L). Answer in both % and ppm (mg/L).

Answer 1

According to ppm here 1 ppm is equivalent to 1part of NaCl for every one million part of water.

Ppm = (mass of solute÷massof solution ) ×1,000,000

Volume of water=1.06L density=1kg/L

Therefore mass of water=density ×volume=1×1.06=1.06kg=1060000mg

Mass of sodium chloride=0.500g=500mg

Sodium chloride dissociate completely in aqueous solution to form sodium cataion Na⁺ and chloride anion Cl-

Total mass of solution=500+1060000=1060500mg

Strength in ppm=(500/1060500)×1,000,000=471ppm

1ppm=0.0001%

Therefore % strength=471/10000=0.0471%