Experiment 3

Objective: Study the Effect of Adding Solutes on the Boiling Point of Water

  Introduction:

This experiment explores how adding solutes, such as sugar, affects the boiling point of water. When a solute is dissolved in water, the solution's molecules are less organized compared to those in pure water, leading to an increase in the boiling point. The boiling point rises with the concentration of the solute, and the purity of the water also plays a role—decreased purity results in a higher boiling point. Additionally, adding a solute to a solvent lowers the solvent's freezing point.

Required Materials:

Round-bottomed flaskDouble-holed corkStand with holder for the round-bottom flaskThermometerOpen-ended glass tubeSugarBunsen burnerWire gauze

Procedure:

1.    Take approximately 50 cc of water in the round-bottomed flask.

2.    Heat the flask using a Bunsen burner.

3.    Note the temperature at which the water begins to boil.

4.    Take ten temperature readings at 30-second intervals for five minutes, then calculate the average boiling point.

5.    Add about 15 g of sugar to the water and repeat the experiment.

Observation:  Adding a solute, such as sugar, to water increases its boiling point

Questions:

1.    What type of flask is required for the experiment? A round-bottomed flask is required for the experiment.

2.    Why is a thermometer used in the experiment? A  thermometer is used to accurately measure the temperature at which the water begins to boil and to observe the change in boiling point after adding the solute.