What makes reactions go faster

Answer Key - Grade 10 Science Worksheet - Challenge Me

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

1. 1.

   A cube of side 3 cm is cut into 27 cubes of side 1 cm. What is the total surface area of the small cubes, Bo?

   162 cm²
2. 2.

   Which change speeds up a reaction without raising its temperature, Jun?

   • Using bigger pieces
   • Cooling it down
   • Using a catalyst
3. 3.

   Which setup reacts fastest: lumps at 20 °C, powder at 20 °C or powder at 40 °C, Kira?

   • Powder at 40 °C
   • Powder at 20 °C
   • Lumps at 20 °C
4. 4.

   What does a car's catalytic converter do, Luz?

   • Speeds reactions that clean the exhaust
   • Makes the engine burn more fuel
   • Cools the exhaust to stop it reacting
5. 5.

   Milo says a catalyst gets used up as the reaction goes. Agree or disagree?

   • Disagree: it comes out unchanged
   • Agree: it is a reactant like the others
   • Agree: it turns into product
6. 6.

   Noah says a catalyst makes a reaction release more energy. Agree or disagree?

   • Disagree: ΔH stays the same
   • Agree: faster means more heat in total
   • Agree: a catalyst adds energy
7. 7.

   Pia says each enzyme in saliva can break down only one food molecule before it is used up. Agree or disagree?

   • Disagree: enzymes are reused
   • Agree: an enzyme gets spent like a reactant
   • Agree: saliva runs out of water
9. 8.

   Using the graph, what is the average rate from 0 to 50 s, Ren?

   • 55 mL/s
   • 2.4 mL/s
   • 1.1 mL/s
10. 9.

    Using the graph, the reaction is run again with a catalyst. What changes, Tala?

    Use the picture in question 8.

    • It makes far more than 55 mL
    • It reaches 55 mL sooner
    • It stops well short of 55 mL
11. 10.

    Using the graph, why is the rate from 0 to 10 s higher than from 40 to 50 s, Zee?

    Use the picture in question 8.

    • The clock runs faster at first
    • More reactant is left early on
    • Gas weighs less at first