Asolution contains 35 grams of kno3 dissolved in 100 grams of water at 40°c. how much more kno3 would have to be added to make it a saturated solution?
(1) 29 g (3) 12 g
(2) 24 g (4) 4 g

The answer is (1) 29 g. The solubility means that one compound can be dissolved in 100 grams of water. The solubility of KNO3 under 40℃ is 64 g. So 64-35=29 grams of KNO3 needs to be added.

Answer the same molecular formula;

Reaction involved in present system is :   c12h22o11 + h2o → 2 c6h12o6the reaction system is obeying following rate law:   rate = k[c12h22o11]thus, it is a first order reaction.now, for 1st order reactionrate constant (k) =  given: initial conc. = 3.0 g, final conc. = 2.7 g, t = 2.5 h∴rate constant (k) =  ∴ k = 0.04215 h-1now, for 1st order reaction, half life = 0.693/k = 0.693/0.04215 = 16.4 hthus correct answer is option b