Fizzies were popular in the ‘60s & ‘70s

They were “instant fizz” tablets sold by the Emerson Drug

Company in the US who also made “Bromo Seltzer” headache remedy.

They work by the reaction of an acid and a base. Today we’re going to try making some but for the best taste, you have to get the ratio just

right!

H3C6H5O7 + 3NaHCO3 Na3C6H5O7 + 3H2O + 3CO2

citric acid + sodium hydrogen carbonate sodium citrate + water + carbon dioxide

balance the equation

H3C6H5O7 + NaHCO3 Na3C6H5O7 + H2O + CO2

citric acid + sodium hydrogen carbonate sodium citrate + water + carbon dioxide

Click to reveal192 g/mol 84 g/mol

calculate the formula mass of each of the two reactants

H3C6H5O7 + 3NaHCO3 Na3C6H5O7 + 3H2O + 3CO2

citric acid + sodium hydrogen carbonate sodium citrate + water + carbon dioxide

In a plastic disposable cup measure out …

• ½ a centimetre of juice concentrate• a level table spoon of icing sugar

• up to 1g of NaHCO3

• half a cup of water

dissolve everything

measure out in a separate cake case up to 1g of citric acid then add to your drink, stir +

taste

First we will make the drink without considering the “stoichiometry”

is your drink too sour? too chalky?

.. or just right?

The only way to get it right every time is to add the chemicals in

the right ratio

H3C6H5O7 + 3NaHCO3 Na3C6H5O7 + 3H2O + 3CO2

citric acid + sodium hydrogen carbonate sodium citrate + water + carbon dioxide

• We’ll add 0.5g of NaHCO3. How many moles do you have in 0.5g?

• How many moles of citric acid will react with one mole of NaHCO3? (look at the ratio in the chemical equation)

• So how many moles of citric acid will you need to add?

• Calculate the mass of citric acid to add …

Let’s work out the ideal ratio for the acid and base to mix in so neither is left over …

Check your answer with me before making up

your second fizzy drink mix to see if it is any

tastier

192 g/mol 84 g/mol

0.5/84 = 0.00595 moles

1/3rd of a mole

0.00595/3 = 0.00198 moles

0.00198 moles x 192 g/mol = 0.38g