M5.2

Before setting out her equipment, Anna asks questions of her friends, peers, and teachers in order to:

• identify previous research

• clarify what is to be investigated.

• enable a hypothesis to be constructed

• all of the above

Which of the following is a valid hypothesis?

• Stirring sugar in coffee will dissolve it.

• The amount of Brand Y granulated sugar that dissolves in a cup of Brand X coffee may increase as the temperature of the coffee increases.

• The surface area of a coffee mug will affect the amount of sugar that can be dissolved in the coffee.

• None of the above

Measuring the volume of a liquid using a measuring cylinder is more precise than using a graduated glass beaker.

Is this statement true or false?

• true

• false

In Anna’s investigation she needs to measure 1.00 g. The electronic balance having the highest resolution is:

• 0 to 1 kg: 1 g increments

• 0 to 500 g: 0.1 g increments

• 0 to 50 g: 0.01 g increments

Why is it important to record the make and brand of chemicals used in an investigation?

• To identify the dependent and independent variables.

• So that the cost can be identified and to ensure that you are not being overcharged.

• So that the investigation can be repeated at a future date and the results compared with those of the original investigation.

• To fill out the conclusion report of the investigation.

Graphing calculators are useful for measuring which type of variable?

• Discrete variables

• Categoric variables

• Continuous variables

• All of the above

As the temperature of the coffee increased, some of it evaporated. How should Anna have solved this problem?

• Anna should have started the experiment again from the beginning

• Anna should have topped up the coffee cup with water from the faucet.

• Anna should have topped up the coffee cup with coffee from the volumetric flask.

• Anna should have ignored it and continued with the experiment.

Which of the following is a valid method to increase the precision of a measurement?

• Using a tool with a higher resolution

• Repeating the measurement multiple times and calculating the average

• Using a tool that is easier to read

• All of the above

Why is it important to control variables in an experiment?

• To ensure that the results are due to the effect of the independent variable and not some other factor

• To make the experiment easier to conduct

• To make the experiment more interesting

• None of the above

What is the purpose of a control group in an experiment?

• To provide a standard of comparison for the experimental group

• To make the experiment more complex

• To ensure that the experiment is fair

• None of the above