Accuracy refers to how close a measured value is to the true or standard value.

A method is described as repeatable if a person uses the same method and obtains the same/similar results when repeating the experiment.

A parallax error occurs when a measurement is not taken at eye-level.

A systematic error is caused by the equipment used.

Evaluating methods for measuring the rate of reaction

Chemistry

In the Industrial Chemistry unit, pupils will build on their knowledge of reaction rates to learn about the industrial processes involving chemical reactions and the factors that affect them.

In the Energy Changes in Reactions unit, pupils learned about bond breaking, bond making, and reaction profiles.

Rate of reaction

What is a potential error that could affect the accuracy of end-point measurements?

What type of error could affect the accuracy of measuring the volume of gas over time?

Which apparatus set-up can cause errors when measuring volumes of gas produced?

It allows direct and simple comparison of reaction rates.

It changes the temperature of the reaction.

Why is measuring an end-point in a reaction useful?

using automated sensors such as light sensors

get a different person to take each reading

How can you reduce subjectivity in observing the end-point of a reaction?

Which key term is used for results that are close to the true or standard value?

Which method would be most suitable for measuring the rate of a reaction that produces a gas as one of its products?

How can we measure the amount of gas produced in a chemical reaction?

Typically what happens to the rate of reaction during a reaction?

The measured volume of gas produced will be higher than the true value.

The measured volume of gas produced will be lower than the true value.

There will be no effect on the volume of gas recorded.

When measuring the volume of gas produced in a chemical reaction, what effect will gas escaping to the surroundings have on the results?

reading the maximum amount of gas produced

measuring how long the reaction took to reach completion

calculating the gradient at specific points

How can we calculate the instantaneous rate of reaction from a volume of gas produced versus time graph?

occurs when an instrument does not reset to zero 

occurs when a measurement is not taken at eye-level

made by the investigator such as timing incorrectly

Match the type of error to the correct definition.

Exit Quiz