117.0g of sodium chloride was dissolved in the solubility in 1.0dm³ of distilled water at 25°C. Determine the solubility in mol dm-³ of sodium chloride at that temperature [Na = 23, Cl = 35.5]

A. 1.0
B. 2.0
C. 3.0
D. 4.0

Correct Answer:

Option B – 2.0

Explanation

Relative molecular mass of NaCl = 23 + 35.5 = 55.5 g/mol
No. of mole of NaCl = 117/55.5 = 2.1 mol