Dilution calculations

Answer Key - Grade 10 Science Worksheet - Challenge Me

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

1. 1.

   0.1 L of 1.2 M sugar water is diluted to 0.4 M. How much water is added, to 0.01 L, Jun?

   0.2 L
2. 2.

   0.5 L of 0.6 M salt water is diluted to 0.2 M. How much water is added, to 0.01 L, Kira?

   1 L
3. 3.

   Bo says diluting salt water removes some of the salt. Which reply fits, Luz?

   • Agree: the added water pushes some salt out
   • Agree: the molarity falls because salt leaves
   • Disagree: the salt stays, spread through more liters
4. 4.

   Esme says that to halve a molarity, you double the volume of solution. Which reply fits, Milo?

   • Agree: twice the volume gives half the molarity
   • Disagree: halve the volume to halve the molarity
   • Disagree: twice the volume quarters the molarity
5. 5.

   2.0 M salt water is diluted to 1.0 M, then that to 0.25 M. By what total factor was it diluted, Pia?

   • 6 times, adding the two factors
   • 1.75 times, from 2.0 − 0.25
   • 8 times
6. 6.

   100 mL of 1.0 M sugar water is diluted to 250 mL; then 50 mL of that is diluted to 200 mL. What is the final molarity, Ren?

   • 0.25 M, from the second step alone
   • 0.10 M
   • 0.40 M, after the first step alone
7. 7.

   1.5 M salt water is diluted 3 times, then 5 times. What is the final molarity, Tala?

   • 0.10 M
   • 0.19 M, from 1.5 ÷ 8
   • 0.50 M, after the first step alone
8. 8.

   A student finds a diluted solution more concentrated than the original. What does that show, Zee?

   • Nothing: water makes the salt stronger
   • An error: dilution always lowers molarity
   • Nothing: dilution can raise the molarity
9. 9.

   0.30 L of 0.60 M salt water is diluted to 0.90 L, and a student gets 1.8 M. Which quick check catches the error, Ari?

   • The answer should be above 0.60 M
   • The answer should be below 0.60 M
   • The answer should equal 0.60 M
10. 10.

    Which answer fits diluting 0.30 L of 0.60 M salt water to 0.90 L, Bo?

    • 0.60 M, the same as the start
    • 0.20 M, a third of the start
    • 1.8 M, three times the start