Lesson E1: Acids, Bases, Alkalis

Lesson E1: Acids, bases, alkalis

Starter activities

Problem solving

· five containers of water

Main activities

E1a Make your own indicator

For each group:

· a cooked beetroot (not pickled) ● a filter funnel

· a knife to cut the beetroot ● filter paper

· a white tile ● two test tubes

· a heatproof mat ● a test tube rack

· a Bunsen burner ● a dropping pipette

· a tripod and gauze ● lemon juice

· a 250 cm3 beaker ● soap solution

· a 250 cm3 conical flask

For the class (optional teacher demonstrations):

· a large piece of filter paper

· 1% phenolphthalein solution

· a paintbrush

· a spray container

· sodium hydroxide solution, 2 mol/dm3 [CORROSIVE]

· three 100 cm3 beakers

· a dropping pipette

· dilute hydrochloric acid (1 mol/dm3) [IRRITANT]

E1b Using plant extracts as indicators

For each group:

· a spotting tile (dimple tile)

· access to a range of plant extracts in labelled beakers with dropping pipettes (the dyes will need to be extracted from the plant material ready for the lesson), for example:

red cabbage blackcurrant

raw beetroot litmus

· access to a range of household and laboratory acids and alkalis (maximum strength

0.4 mol/dm3), for example:

hydrochloric acid lemonade

sulphuric acid sodium hydrogencarbonate solution

nitric acid calcium hydroxide solution (limewater)

lemon juice ammonia solution

vinegar sodium hydroxide solution

Lesson E2: How acidic?

Main activities

E2a Dip and check

For each group:

· a range of household substances with various pHs (e.g. bleach, washing up

liquid, washing powder, soap, oven cleaner, vinegar, lemon juice, etc.) Each

should be mixed with or dissolved in a beaker of water for testing. The original

packaging should be displayed and the beakers labelled to match the packaging.

· a glass rod for each beaker

· a book of pH paper

Lesson E3: Taking away acidity

Main activities

E3a Adding an acid to an alkali

For each group:

· universal indicator colour chart

· universal indicator solution

· two 100 cm3 beakers

· two 50 cm3 measuring cylinders

· two dropping pipettes

· a stirring rod

· 100 cm3 of hydrochloric acid, 0.4 mol/dm3

· 100 cm3 of sodium hydroxide solution, 0.4 mol/dm3

E3b Using a datalogger to check pH changes

For each group:

· a 250 cm3 beaker

· a 100 cm3 measuring cylinder

· a 50 cm3 measuring cylinder

· a 100 cm3 dropping funnel

· a magnetic stirrer

· a retort stand and clamp

· a pH sensor

· a datalogger with printer

· 100 cm3 of hydrochloric acid, 0.4 mol/dm3

· 100 cm3 of sodium hydroxide solution, 0.4 mol/dm3

E3cde Investigate: How well do antacids work?

Equipment may vary slightly according to the method chosen by pupils in their plans.

For each group:

· four 250 cm3 beakers

· a 100 cm3 measuring cylinder

· a stirring rod

· hydrochloric acid, 0.1 mol/dm3, labelled ‘stomach acid’

· four different brands of antacid

· a stopwatch

· universal indicator solution

· a universal indicator colour chart

Additional for Extension:

· a datalogger with printer (optional)

· a pH sensor (two, if available)

· a retort stand and clamp (depending on type of sensor)

· a plastic stirring rod

E3c How well do antacids work?

· four beakers

· a measuring cylinder

· universal indicator solution

· a stirring rod

· a solution of ‘stomach acid’

· a universal indicator chart

· a stopwatch

· four different brands of antacid

This list is in Microsoft Word, so it can be customised to fit each school’s requirements.