Solubility and Saturation: Temperature Effects
Year 9 Science Understanding how temperature affects solutions AQA 4.3.2 Curriculum
Learning Objectives
Define solubility and saturation Explain how temperature affects solubility Interpret solubility graphs and trends Apply knowledge to real-world examples
What is Solubility?
The maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature Measured in grams per 100g of water (g/100g H₂O) Different substances have different solubilities Example: Sugar is highly soluble, sand is insoluble
Understanding Saturation
Saturated solution: No more solute can dissolve Unsaturated solution: More solute can still dissolve Supersaturated solution: Contains more dissolved solute than normally possible Excess solute forms crystals or precipitate
Quick Check
If you add 40g of salt to 100g of water at 20°C, and only 36g dissolves, what type of solution do you have? A) Unsaturated B) Saturated C) Supersaturated
Temperature and Solubility
Most solids become MORE soluble as temperature increases Particles move faster at higher temperatures More energy available to break intermolecular forces Gas solubility DECREASES as temperature increases
Solubility Graph
Reading Solubility Graphs
{"left":"Find temperature on x-axis\nRead up to the substance curve\nRead across to y-axis for solubility value","right":"Compare different substances at same temperature\nIdentify which dissolves more at specific temperatures\nPredict what happens when solutions cool down"}
Practical Application
Use the graph to answer: How much potassium nitrate dissolves in 100g water at 80°C? What happens if this solution cools to 20°C? Calculate the mass of crystals formed
Summary and Key Points
Solubility is the maximum amount that dissolves at a given temperature Saturated solutions cannot dissolve more solute Temperature usually increases solid solubility Solubility graphs help predict crystallization Understanding these concepts helps explain everyday phenomena