18.From the following list of aqueous solutions and water, select the one with the highest boiling point. a.1.0 mKNO3b.2.0 mC12H22O11(sucrose)c.0.75 mNaCld. pure watere.0.75 mCuCl2

e. 0.75m CuCl

Explanation:

The boiling point of a solvent increases with the addition of moles of solute. The formula is:

ΔT = i×Kb×m

Where ΔT is boiling point elevation, i is Van't Hoff factor, Kb is ebulloscopic constant and m is molality of solution.

That means the higher i×m, the highest boiling point. Thus:

a. 1.0m KNO₃: i×m = 2ₓ1.0m = 2

b. 2.0m C₁₂H₂₂O₁₁: i×m = 1ₓ2.0m = 2

c. 0.75m NaCl: i×m = 2ₓ0.75m = 1.5

e. 0.75m CuCl: i×m = 3ₓ0.75m = 2.25

e. 0.75m CuCl has the highest boiling point

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.