Investigating Solubility
This practical lesson covers:
- The solubility of a solid in water at a specific temperature
Investigating the relationship between temperature and solubility
Aim
To investigate the solubility of a solid in water at a specific temperature.
Background information
When a soluble substance is added to water it dissolves. A saturated solution is formed when no more solute can be dissolved in the water. The amount of solute that can be added to a solvent before it becomes saturated, varies with temperature. In this practical, you will investigate the solubility of powdered sodium chloride at different temperatures.
Equipment
- 250 cm3 beaker
- Thermometer
- Digital mass balance
- Glass rod
- Powdered sodium chloride
Method
- Pour 200 cm3 of deionised water into a 250 cm3 beaker.
- Place beaker in a water bath at the desired temperature.
- Add known masses of the powdered sodium chloride and mix with a glass rod.
- Repeat step 3 until no more sodium chloride will dissolve.
- Record the total mass added.
- Repeat at 5 different temperatures.
What is formed when a soluble substance is added to water and no more solute can be dissolved?
a dilute solution
a saturated solution
an unsaturated solution
a supersaturated solution
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How does the amount of solute that can be added to a solvent before it becomes saturated vary with temperature?
it varies randomly with temperature
it increases with increasing temperature
it decreases with increasing temperature
it remains constant
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What is the purpose of using a water bath in this experiment?
to increase the rate of dissolution
to maintain a constant temperature
to prevent the solution from becoming saturated
to allow the solute to dissolve completely
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What is the role of the glass rod in this experiment?
to determine the solubility of sodium chloride
to measure the temperature of the solution
to mix the solution
to weigh the powdered sodium chloride
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What is the dependent variable in this experiment?
the temperature of the water
the volume of water used
the mass of sodium chloride added
the type of solute used
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