Quiz What is an acid? What is a base? Give 3 properties that acids and bases each have in general. What does the pH scale indicate? You tested an unknown substance with universal indicator and it turned red, is the substance acidic or basic? You tested another unknown substance with universal indicator and it turned blue, is the substance acidic or basic? What did the anta-acid tablet do to the HCl solution we tested last week?

Neutralization You may be wondering, what happens when you mix an acid and a base together? Explosion? Or nothing happens? In fact acid-base reactions happen all the time and we call this type of reaction neutralization. e.g. Drinking coke.

Neutralization Bee sting: Bee sting venom are acidic and can be neutralized with a base such as baking soda. However wasp stings are alkaline and need acid to neutralize.

Neutralization Stomach acid: Stomach acid is very strong and helps us digest food and kill germs. However, when there’s too much stomach acid it may become quite painful (such as heart burn, and no, it’s not your heart burning). Anta acid tablets can help ease the symptoms of excess stomach acid by neutralizing it. (Ring a bell about what anta acid is?)

Neutralisation Reactions acid + base  salt + water Acids and bases are chemically the opposite of each other. Mixed together they cancel each other out, producing neutral salt and water instead.

Acid – Base Reactions A reaction between an acid and a base is called neutralization. An acid-base mixture is not as acidic or basic as the individual starting solutions.

Copy notes on the board.

Chemical equations for practice Write the symbol equation for Aluminium oxide  aluminium and oxygen Iron metal + oxygen  Iron (III) oxide Magnesium metal + chlorine gas  magnesium chloride Copper(II) chloride  Copper metal + chlorine gas Sulfur dioxide + oxygen  sulfur trioxide.