Cooking

Question 1

Are chemical changes reversible or irreversible?

Answer 1

Irreversible

Question 2

Name so indicators that a chemical change has taken place

Answer 2

• New substance formed

- Energy changes take place

Question 3

What happens to enzymes when they are heated?

Answer 3

They denature

Question 4

What happens when enzymes denature?

Answer 4

Their bonds are broken and so they form new bonds elsewhere, changing the shape of the enzyme and creating a new substance

Question 5

What is the role of anti-oxidants in food?

Answer 5

To stop the food reacting with oxygen, to preserve it for longer

Question 6

Which part of an emulsifier is hydrophilic and which is hydrophobic?

Answer 6

The head is hydrophilic and the tail is hydrophobic

Question 7

What do emulsifiers do to oil and water? How?

Answer 7

They allow the water and oil to mix, without separating, because the emulsifier has a hydrophilic head, which sits in water, and a hydrophobic tail, which sits in oil, and therefore it is able to bind them together.

Question 8

What is the equation for baking powder being heated?

Answer 8

[2]NaHCO(3) + Na(2)CO(3) + H(2)O + CO(2)

[Balancing numbers]
Small numbers