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

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

   Use the picture in question 4.

   • Time itself slows down
   • Reactants are being used up
   • 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
   • By 10 s
   • It keeps making gas past 60 s
8. 7.

   Why does warming a reaction speed it up, Noah?

   • Warm particles stop colliding
   • Particles move faster and hit harder
   • Heat makes each particle grow much bigger
9. 8.

   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
10. 9.

    A crushed antacid tablet fizzes faster in water than a whole one. Why, Tala?

    • The water is colder
    • It has more mass
    • It has more surface area
11. 10.

    Enzymes in saliva speed up the breakdown of food. What are enzymes acting as, Zee?

    • Products
    • Catalysts
    • Fuels