Year 10 Science · Unit 2 · Lesson 18

Investigating Reaction Rates

Foundation Worksheet

Name

Date

Class

Learning Goals

Sequence the steps of a reaction rate investigation in the correct order.
Distinguish between must-have, good practice, and error elements of investigation design.
Identify the independent, dependent, and controlled variables in a reaction rate experiment.

Warm Up

Order the steps

Number the steps from 1 to 8 to show the correct order for conducting a reaction rate investigation. Step 1 = what happens first.

Order	Step
	Record data in a prepared table, noting the time taken for each trial
	Write an aim and a testable hypothesis using "if… then… because…" format
	Repeat each trial at least three times to improve reliability
	Set up equipment and prepare solutions at the specified concentrations
	Identify the independent variable, dependent variable, and at least three controlled variables
	Write a CER conclusion linking your data to collision theory
	Put on safety glasses; note corrosive hazard of HCl on the risk assessment
	Calculate averages, identify any anomalous results, and draw a graph

Your Turn

Sort it!

Write each investigation element from the pool into the correct category box. Each item belongs to exactly one category.

State a clear hypothesis before collecting data Change two variables at once to save time Use the same mass of marble chips in each trial Calculate the average from three trials Record only the results that match your prediction Measure volumes with a graduated cylinder, not estimation Include at least one control trial (no acid) Ignore anomalous results without noting them Wear eye protection when handling HCl Describe the trend in data before writing a conclusion

Must Have

Good Practice

Error (do NOT do this)

Show What You Know

1. In a thiosulfate clock reaction, a student times how long it takes for the solution to turn cloudy enough to hide an "X" mark underneath. State the independent variable, dependent variable, and two controlled variables for this investigation.

Recall 2 marks

2. Explain why safety glasses must be worn when using hydrochloric acid (HCl) in a reaction rate experiment. Describe one additional safety precaution for this experiment.

Recall 2 marks

Wrap Up

In one sentence, explain why repeating an experiment three times gives more reliable results than doing it once.