Saturated, unsaturated and supersaturated solutions

Answer Key - Grade 10 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Salt dissolves up to 36 g per 100 g of water at 25 °C. A cup of 100 g of water at 25 °C holds 20 g. How many more grams could dissolve, Ari?

   16 g
2. 2.

   Baking soda dissolves up to 9.6 g per 100 g of water at 20 °C. A cup of 100 g of water at 20 °C holds 5 g. How many more grams could dissolve, Bo?

   4.6 g
3. 3.

   Sugar dissolves up to 200 g per 100 mL of water at 25 °C. A jar of 100 mL of water holds 150 g. How many more grams could dissolve, Kira?

   50 g
4. 4.

   Salt's limit is 36.0 g per 100 g of water at 25 °C. A cup at 25 °C holds 20 g in 100 g of water. Which is it, Jun?

   • Unsaturated: more salt could still dissolve
   • Saturated: it already holds as much salt as it can
   • Supersaturated: it holds more salt than its 36.0 g limit
5. 5.

   Salt's limit is 36.0 g per 100 g of water at 25 °C. A cup at 25 °C holds 36.0 g in 100 g of water. Which is it, Luz?

   • Unsaturated: a few more grams of salt will still dissolve
   • Supersaturated: the salt is past its limit
   • Saturated: it holds as much as it can
6. 6.

   Sugar's limit is 200 g per 100 mL of water at 25 °C. A cooled, clear solution holds 250 g per 100 mL at 25 °C. Which is it, Milo?

   • Unsaturated: it could still hold even more sugar
   • Saturated: it sits right at its sugar limit
   • Supersaturated: above the limit, and unstable
7. 7.

   Salt crystals stay undissolved at the bottom of a well-stirred cup of salt water. What does that show, Pia?

   • The solution is supersaturated, since solid is left over
   • The solution is saturated
   • The solution is unsaturated, since the crystals are new
8. 8.

   Why is a supersaturated solution unstable, Ren?

   • It holds more than it can keep dissolved, so crystals can form
   • It holds less solute than it can, so it slowly dries out
   • Its undissolved crystals keep growing larger on the bottom
9. 9.

   A salt crystal is dropped into an unsaturated salt solution. What happens, Tala?

   • It sits on the bottom, since the solution is full
   • It dissolves, since there is still room
   • Many new crystals form around it at once
10. 10.

    A sugar crystal is dropped into a supersaturated sugar solution. What happens, Esme?

    • It dissolves, since the solution still has room left
    • Extra sugar crystallizes out around it
    • Nothing happens, just as in a saturated solution