Hot water, cold water
Temperature changes solubility.
Tea and soda
Sugar dissolves much better in hot tea than in cold water. A bottle of soda left in the sun loses its fizz fast.
What do these two facts suggest about temperature?
What this lesson covers
The idea
The solubility of a solid in a liquid generally increases with temperature, while the solubility of a gas in a liquid generally decreases as temperature rises.
Tea and soda
Sugar dissolves much better in hot tea than in cold water. A bottle of soda left in the sun loses its fizz fast.
What do these two facts suggest about temperature?
- More solid dissolves when hot, but less gas stays dissolved
- Heat makes everything dissolve better
- Temperature has no effect on dissolving
Change the temperature
Move the temperature. Orange dots are dissolved solid, white blocks are solid left over, purple dots are dissolved gas.
Solubility changes with temperature
The solubility of a solid in a liquid generally increases as the temperature increases. The solubility of a gas in a liquid generally decreases as the temperature increases.
This is why we always state the temperature along with the solubility.
The values are standard data (grams in 100 g of water, 1 atmosphere). They are used here only as an example.
Notes
A solid generally dissolves more as the temperature rises. A gas generally dissolves less.
Check yourself
Sugar is stirred into water. How does a solid’s solubility generally change when the water is heated?
How does the solubility of a gas in a liquid generally change when the temperature rises?
Why does a warm soda go flat faster than a cold one?
Which pair is correct?
- It decreases. That is the trend for gases.
- It increases — correct. Yes.
- It stays exactly the same. It changes with temperature.
- It increases. That is the trend for solids.
- It stays the same. It changes with temperature.
- It decreases — correct. Yes. A warm soda loses its gas.
- More carbon dioxide dissolves in warm water. The solubility of a gas falls as it gets warmer.
- Less carbon dioxide stays dissolved in warm water — correct. Yes.
- Warm soda has no gas to begin with. The gas was dissolved when it was made.
- Solid: less dissolves when hot. Gas: more dissolves when hot. Reversed.
- Both dissolve more when hot. A gas dissolves less when it is hot.
- Solid: more dissolves when hot. Gas: less dissolves when hot — correct. Yes.