Indigestion

Your stomach produces hydrochloric acid to:
-Kill Bacteria
-Digest food


If there is bacteria on your food it is broken down by digestive enzymes which need acidic conditions in order to work properly.

If there is too much hydrochloric acid in the stomach it can cause indigestion pain.

Sometimes the acid can escape from the top of the stomach causing pain in the tube leading to the mouth. This is known as heartburn though it has nothing to do with the heart.

Medicines called antacids are able to get rid of excess stomach acids. They contain bases - substances that react with acids.

The neutralisation reaction between an acids and a base produces water and salt. Some bases are soluble and a base dissolved in water is called an alkali.

Acid + Base -----> Salt + Water

Acids and alkalis can be described using the PH scale.

A  neutral liquid (e.g. water) has a PH of 7.

You can find out whether a liquid is an acid or alkali using a indicator.

Litmus paper is an indicator

Blue litmus paper turns red under acid conditions and red litmus paper turns blue under alkaline conditions but the paper must be damp to work.

Key Words:

Digested

Antacids

Bases

Salt

Acid

Alkali

PH Scale

Indicator

Litmus Paper

Questions:

1) What causes indigestion?

2) What is an antacid?

3) Stomach acid would turn universal indicator orange, what is its PH? (hint: use the PH scale)

What you should know:

• 3.1 Know that hydrochloric acid is produced in the stomach to:
  • a) help digestion
  • b) kill bacteria
• 3.2 Be able to describe indigestion remedies as containing substances that neutralise excess stomach acid.