Practical Skills Revision 1

Fill in the blanks.

In a titration experiment, a _ is used to measure fixed volume of solution accurately. Sometimes, a _ _ is used as it is simpler to use. A _ measures a range of volumes accurately.

Which of the following shows burette reading recorded correctly?

• 17

• 17.0

• 17.1

• 17.10

What is the volume of solution added based on the diagram given below?

• 11.3

• 12.7

• 11.30

• 12.70

Select the best titration results in the table given.

• Titration numbers 1 and 2

• Titration numbers 2 and 3

• Titration numbers 1 and 3

• Titration numbers 1, 2, 3

Which of the following show temperature reading recorded to nearest 0.5 ^oC?

• 30 ^oC

• 32.0 ^oC

• 29.2 ^oC

• 29.5 ^oC

The temperature change of a reaction is being measured in a beaker.

How can this be improved?

• Use a measuring cylinder instead.

• Use a polystyrene (styrofoam) cup instead of a beaker as it is a better thermal insulator.

• Nest a styrofoam cup in a beaker.

• Place a lid on styrofoam cup to minimise heat loss/gain

How can the accuracy of a measurement be improved?

• Repeat the experiment.

• Repeat the experiment and select best results.

• Repeat experiment and calculate average.

• Select best results from repeated experiments and calculate average.

Fill in the blanks on how the trend or relationship of experimental data can be concluded.

Repeat the experiment over a larger _ and at smaller intervals.

Plot a graph of _ variable against _ variable.

If the graph is a straight line passing through the origin, the relationship is _ proportional.

A student does an experiment to investigate how rate of a reaction changes with concentration. He starts a stopwatch on adding a known mass of carbonate to acid. When all the carbonate has reacted, he stops the stopwatch and records the reaction time. The results are shown in a table.

State which experiment has an anomalous reaction time which does not fit in with the pattern of the other results.

• experiment 1

• experiment 2

• experiment 3

• experiment 4

• experiment 5

A student does an experiment to investigate how rate of a reaction changes with concentration. He starts a stopwatch on adding a known mass of carbonate to acid. When all the carbonate has reacted, he stops the stopwatch and records the reaction time. The results are shown in a table.

State which experiment has the smallest rate of reaction.

• experiment 1

• experiment 2

• experiment 3

• experiment 4

• experiment 5