Neutralisation

Intent:

To be able to describe a neutralisation reaction in terms of pH change.

Setting the scene: taking a bath

You want to have a lovely WARM bath.

Looking at the picture, how would you run your bath?

Describe how you would run your bath using the picture to help you.

Answer

Add lots of hot water first then add some cold water and check the temperature with your elbow. If it's still too hot, add some more cold water and check again.....keep doing this until the temperatur is just right

INvestigation

Use the apparatus diagram above to help you work out the method for your investigation.

Are then any health and safety risks involved in the investigation?

Neutralisation

Use the number line below to work out the mathematical problems.

-6 + 6
7 - 7
-8 + 10

Now do the same again, but this time with the pH scale

(This is not how it actually works - just and example)

1 + 6
7 - 6
5 + 8

Find the mid point to get an approximate value.

Assuming 2 things.

Concentrations of acid and alkali are the same; and
That the volumes of the acid and alkali were the same.

What approximate pH would you expect if I mixed.

pH3 acid with pH10 Alkali?
pH14 alkali with a pH2 Acid?
pH4 acid with a pH12 alklai?

Bees stings are Acidic

How do you treat a Bee sting?

Wasp stings are alkaline

How do you treat a Wasp sting?

Would a Bee sting remedy work on a Wasp sting?

Balancing act

Acids have more H+ and alkalis have more OH-

If I add more acid the balance would move to the H+ side.

If I add more alkali the balance would move to the OH- side.

Back to Acids and Alkalis

Page updated

Google Sites

Report abuse