Calculate the boiling point of a 3.5 % solution (by weight) of sodium chloride in water. Kb of H2O = 0.512 oC/M

The boiling point of the solution is

Explanation:

We are given:

3.5 % (by weight) NaCl

This means that 3.5 g of NaCl is present in 100 g of solution

Mass of solvent = Mass of solution - Mass of solute

Mass of solvent (water) = (100 - 3.5) g = 96.5 g

Elevation in the boiling point is defined as the difference between the boiling point of the solution and the boiling point of the pure solvent.

The expression for the calculation of elevation in boiling point is:

OR

......(1)

where,

Boiling point of pure solvent (water) =

Boiling point of solution = ?

i = Vant Hoff factor = 2 (for NaCl)

= Boiling point elevation constant =

= Given mass of solute (NaCl) = 3.5 g

= Molar mass of solute (NaCl) = 36.5 g/mol

= Mass of solvent (water) = 96.5 g

Putting values in equation 1, we get:

Hence, the boiling point of the solution is

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.