AQA practicals Chemistry Рchanges in reaction rate 

Investigate how changes in concentration affect the rates of reactions by a method involving measuring the volume of a gas produced and a method involving a change in colour or turbidity.
This should be an investigation involving developing a hypothesis

Use of appropriate apparatus to make and record a range of measurements accurately, including mass, time, temperature, and volume of liquids and gases.
Use of appropriate apparatus and techniques for conducting and monitoring chemical reactions.
Making and recording of appropriate observations during chemical reactions including the measurement of rates of reaction by a variety of methods such as production of gas and colour change.
Safe use and careful handling of gases, liquids and solids, including careful mixing of reagents under controlled conditions, using appropriate apparatus to explore chemical changes.

Use scientific theories and explanations to develop hypotheses.
Plan experiments or devise procedures to make observations, produce or characterise a substance, test hypotheses, check data or explore phenomena.
Apply a knowledge of a range of techniques, instruments, apparatus, and materials to select those appropriate to the experiment.
Carry out experiments appropriately having due regard for the correct manipulation of apparatus, the accuracy of measurements and health and safety considerations.
Make and record observations and measurements using a range of apparatus and methods.
Evaluate methods and suggest possible improvements and further investigations.
Recognise and use expressions in decimal form.
Use ratios, fractions and percentages.
Make estimates of the results of simple calculations.
Use an appropriate number of significant figures.
Find arithmetic means.
Translate information between graphical and numeric form.
Understand that y = mx + c represents a linear relationship.
Plot two variables from experimental or other data.
Determine the slope and intercept of a linear graph.
Draw and use the slope of a tangent to a curve as a measure of rate of change.

Typical questions