Chemical Reactions

What is a chemical reaction?

A chemical change is when two or more things react to each other and produce something new.

What are the signs of a chemical reaction?

1. A change in colour

2. A change in temperature

3. Formation of gas

4. The creation of a solid

5. Creates light and/or smell

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What is the rate of reaction?

The rate of reaction is how long it takes for a chemical reaction to complete. For example, how long it takes for coke to stop fizzing.

What are the factors that affect the rate of reaction?

There are four factors that after the rate of reaction;

1. The surface area of the reactants. The surface area is the sum of all areas of the faces of an object. For example, if you put a large Berocca tablet into one glass and a smaller Berocca tablet in another, the glass with the larger tablet will take a longer time to dissolve compared the glass with the smaller tablet.

2. The concentration of a reactant. The concentration of is just how much of something there is. For example, the is a high concentration of oranges in the picture.

3. The temperature of the reactants. For example, an ice cube will melt faster in hot water than it will in cold water.

4. The use of a catalyst. A catalyst is something that is added to a chemical reaction to speed it up but does not get used up in the process.