Rates of reaction

If you add vinegar to bicarbonate of soda, the mixture will fizz – this shows that a gas is being given off.

If you boil water in a kettle, steam is produced.

Task 

Only one of these is an example of a chemical reaction – which do you think it is?

A) Boiling a kettle                                         B) Adding vinegar to bicarbonate of soda

Clue: The answer is the one which produces a new substance

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Answer:

When water boils, the liquid water turns to steam, but it is still water even though it has changed into a gas.Steam can also change back to water. So this is an example of a physical change.

When vinegar and bicarbonate of soda meet, the gas given off is a new substance called CARBON DIOXIDE. It is not possible to separate these back into vinegar and bicarbonate of soda.

So in this case: a chemical reaction has taken place. Adding vinegar to bicarbonate of soda is the correct answer.