Question

unit 3: factors affecting the rate of chemical reaction
instructions: read each scenario carefully and determine which factor affects the rate of reaction.
choose your answer from the word bank.

1. anna wants to dissolve sugar faster in her tea. she notices that the sugar dissolves

much faster in hot tea than in cold tea.

1. ethan is building a campfire and has large logs and small sticks. he realizes that the

small sticks catch fire and burn faster than the large logs.

1. during a science experiment, maya adds a small amount of enzyme to hydrogen

peroxide, causing it to decompose rapidly into water and oxygen. without the enzyme, the reaction would
take much longer.

1. liam observes that when he uses a higher concentration of bleach solution to clean,

the stains are removed faster compared to when he uses a diluted solution.

1. in a bakery, bread dough rises faster in a warm kitchen than it does in a cooler

environment. the yeast produces carbon dioxide gas, causing the dough to rise.

1. serena mixes baking soda with vinegar and sees an immediate fizzing reaction.

however, when she mixes table salt with vinegar, no reaction occurs.

1. james is preparing a chemistry demonstration. he crushes a tablet of antacid before

adding it to water, observing that it dissolves much faster than when he used a whole tablet.

1. a gardener uses two different fertilizer solutions on identical plants. he notices that

the plant with the more concentrated fertilizer grows significantly faster.

1. for a cooking experiment, maria notices that milk spoils faster when left outside the

refrigerator on a hot day than when kept in the fridge.

1. during the decomposition of hydrogen peroxide, placing a piece of manganese

dioxide in the solution significantly speeds up the release of oxygen bubbles.

1. ben tries to ignite a piece of charcoal, but it takes a long time to burn. when he

crushes the charcoal into powder, it ignites and burns more quickly.

1. sarah is conducting an experiment on the effect of acid rain. she finds that statues

deteriorate faster when exposed to more acidic rain than when exposed to less acidic rain.

1. emily tries to grow crystals from a salt solution. she notices that the crystals form more

quickly when she heats the solution compared to when she leaves it at room temperature.

Explanation:

Step1: Analyze each scenario

• Scenario 1: Sugar dissolves faster in hot tea (higher temperature).
• Scenario 2: Small sticks (larger surface area) burn faster.
• Scenario 3: Enzyme (catalyst) speeds up hydrogen peroxide decomposition.
• Scenario 4: Higher concentration of bleach (concentration) removes stains faster.
• Scenario 5: Warm kitchen (temperature) makes bread dough rise faster.
• Scenario 6: Baking soda reacts with vinegar (nature of reactant), table salt doesn't.
• Scenario 7: Crushed antacid (larger surface area) dissolves faster.
• Scenario 8: More concentrated fertilizer (concentration) makes plant grow faster.
• Scenario 9: Hot day (temperature) makes milk spoil faster.
• Scenario 10: Manganese dioxide (catalyst) speeds up hydrogen peroxide decomposition.
• Scenario 11: Crushed charcoal (larger surface area) ignites faster.
• Scenario 12: More acidic rain (concentration) makes statues deteriorate faster.
• Scenario 13: Heating solution (temperature) makes crystals form faster.

Answer:

1. Temperature
2. Surface Area
3. Catalyst
4. Concentration
5. Temperature
6. Nature of Reactant
7. Surface Area
8. Concentration
9. Temperature
10. Catalyst
11. Surface Area
12. Concentration
13. Temperature