What makes reactions go faster

Answer Key - Grade 10 Science Worksheet - Building Confidence

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

1. 1.

   A reaction gives off 60 mL of gas in 30 s. What is its average rate in mL per second, Ari?

   2 mL/s
2. 2.

   A reaction gives off 45 mL of gas in 15 s. What is its average rate in mL per second, Bo?

   3 mL/s
3. 3.

   A reaction gives off 90 mL of gas in 60 s. What is its average rate in mL per second, Esme?

   1.5 mL/s
5. 4.

   Using the graph, when is the reaction fastest, Jun?

   • At 40 s
   • At the very end
   • At the start
6. 5.

   Using the graph, why does the reaction slow down, Kira?

   Use the picture in question 4.

   • Reactants are being used up
   • Time itself slows down
   • The gas made is getting much heavier
7. 6.

   Using the graph, by when has the reaction stopped making gas, Luz?

   Use the picture in question 4.

   • By about 50 s
   • It keeps making gas past 60 s
   • By 10 s
8. 7.

   What must reactant particles do to react, Milo?

   • Collide with enough energy
   • Stay perfectly still in one place
   • Avoid touching
9. 8.

   Why does warming a reaction speed it up, Noah?

   • Heat makes each particle grow much bigger
   • Warm particles stop colliding
   • Particles move faster and hit harder
10. 9.

    What does a catalyst do, Pia?

    • Becomes the main product of the reaction
    • Speeds a reaction and stays unchanged
    • Slows a reaction and is used up
11. 10.

    Why does milk stay fresh longer in the fridge, Ren?

    • Cold slows the spoiling reactions
    • Cold kills the milk's flavor
    • The fridge adds a catalyst