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/ Activity: How to make sherbet
WARNING: This experiment is edible! Make sure you use clean equipment.
You will need
  • Icing sugar
  • Citric acid
  • Bicarbonate soda
  • Flavoured jelly crystals
  • A teaspoon
  • A dessert spoon
  • A small mixing bowl
  • A container or bag to keep you sherbet in (unless you eat it all at once)
What to do
  1. Add 1 level teaspoon of citric acid crystals to the bowl.
  2. Add 1 level teaspoon of bicarbonate of soda to the bowl.
  3. Now add 3 heaped dessert spoons of icing sugar.
  4. Add at least 2 level dessert spoons of jelly crystals (or more to taste).
  5. Place a small amount, about half a teaspoon on your tongue.
  6. After tasting you may need to vary the ingredients. If it is too bitter add more sugar, if there isn't enough fizz you may need to add either bicarbonate soda or citric acid. Make sure you add only in small amounts, remember you can always add more but it is very hard to remove some.
What's happening?
You have just created an acid-base reaction in your mouth. When you combine an acid (in this activity the citric acid) and an alkaline (the bicarbonate soda) with saliva they mix together to create a gas in the form of lots of tiny bubbles. This is called an acid-based reaction and it's what gives sherbet its fizz. You are actually feeling the sensation of carbon dioxide bubbles on your tongue. These are the same bubbles that are in fizzy drinks.
The icing sugar is needed to add sweetness as the citric acid and bicarbonate soda are quite sour. Citric acid is one of the acids found in lemons, oranges and limes. That is why they are called 'citric fruit'. The other acid in lemons and other citric fruit is called ascorbic acid. This is commonly known as vitamin C.
The jelly crystals add flavour.
Applications
Acids and bases can be found in many places. There is acid in lemon juice, car batteries and bee stings. Detergents found in the home are a common example of a base. Sherbet is most commonly known as Whiz-Fizz or as a legendary 1970's rock band, ' You messed about, I caught you out, Howzat? ' They were one of our most successful Australian pop groups who eventually fizzled out.
Acids and bases are chemical compounds. To understand the difference, first we need to know that an ion is a molecule or atom that has an electrical charge. Normally there are equal numbers of positive and negatively charged particles in an atom or molecule, so they cancel out and there is no overall charge.
There are several ways to define an acid or base, but one of the most common is:
  • An acid is a compound that can give up a positively-charged hydrogen ion in a chemical reaction.
  • A base is a compound that will join onto a hydrogen ion in a chemical reaction.
Acids are often found in living things. The "A" in DNA stands for "acid". Bases are often found in cleaning compounds.
Related activities
  • Indicator Solution
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Add 1 level teaspoon of citric acid crystals

Add 1 level teaspoon of bicarbonate soda

Add at least 2 level dessert spoons of jelly crystals (or more to taste)