Rates of reaction

Rocket fuel needs to react quickly in order to achieve lift off.

What is RATE? 

How fast a chemical reaction happens is a very important consideration.

If paint dries too quickly it will become impossible to apply.

If the fuel in a rocket burns too slowly - the rocket will not get off the ground

 Task 1. Consider the word RATE.

  • ​When we look at applying for a job we will normally want to know about the rate of pay.
  • When we save or borrow money we will want to know about the interest rate which applies.
  • When looking at using chemical reactions we will want to know about the rate of reaction.

Try to write a definition of each of the three rates mentioned above​. What quantity is involved in all three?

 Experiment 1

 Experiment 2

Task 3 

Compare the rate of reaction in each experiment.

What can you say about the relationship between rate and concentration ?


Rates in the lab 

The video shows a classic reaction being performed.

Task 2. Watch the first video closely.

Two colourless solutions are mixed in a beaker. After a while the solutions react together to produce a cloudy suspension.  The cross at the bottom of the beaker can no longer be seen.

The two solutions used are sodium thiosulfate and dilute hydrochloric acid

  • Try to work out and write down what elements are present in the two solutions. Look up the names if necessary.
  • the cloudy suspension is actually fine particles of one of these elements. Which element do you think it is?
  • What single measurement could you make with this reaction which would give you an idea of the rate of the reaction? 

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