Forty (40) grams of sodium nitrate were added to 50cm³ of water to give a saturated solution at 289K. If the solubility of the salt is 10.50 moldm^3 at the same temperature, what percentage of the salt is left undissolved'? [Na = 23, N = 14 and 0 = 16]

• A.11.56%
• B.2.55%
• C.5.88%
• D.12.45%