Liquids Day

Welcome to Liquids Day.

This is day 1 in the series of Properties of Materials Days.

These are your objectives for today:

a. You will know that some materials will dissolve in liquid to form a solution, and describe how to recover a substance from a solution.
b. You will use knowledge of liquids to decide how mixtures might be separated, including through filtering and evaporating.
c. You will demonstrate that dissolving, mixing and changes of state are reversible changes.

Session One – Technical Stuff (a, b, c)

Most of these words have other not-so-scientific meanings too.

Matter is the physical part of the universe.

State of Matter means one of the four principal conditions in which matter exists: solid, liquid, gas, and plasma

(An aside note: Plasma (from Ancient Greek πλάσμα​, meaning ‘moldable substance’) is one of the four states of matter. Plasma can be artificially generated by heating or subjecting a neutral gas to a strong electromagnetic field. Neon signs and lightning are examples of partially ionized plasma.)

A liquid is matter which is not solid but which flows and can be poured, for example water.

The separation of two or more things is the fact that they become separate, and are not linked.

Reversible means capable of returning to an original condition.

A solution is a specific type of mixture in which a solid substance has been dissolved into a liquid.

  • The solute is the substance that is being dissolved by another substance.
  • The solvent is the substance that dissolves the other substance.

Dissolution is the act or process of dissolving. If a substance dissolves in liquid or if you dissolve it, it becomes mixed with the liquid and disappears.

Evaporation is when a liquid changes to a gas due to an increase in temperature.

Filtration is the passage of liquid through a filter or other material that prevents passage of certain molecules, particles, or substances.

Shopping List:

  • 5 clear glass containers (such as mason jars)
  • metal spoons to stir
  • measuring cups and spoons
  • cheap salt
  • clear soda (Sprite or 7up)
  • lemon juice
  • white vinegar
  • hydrogen peroxide
  • cheap oil (vegetable or sunflower)
  • high sugar content candy (Skittles or Nerds)
  • activated charcoal (from the fire pit?)
  • soil
  • lake water
  • epson salts
  • plant pots
  • sticky labels or similar

Session Two – Dissolving Salt (a, c)

Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound. Salt in its natural form as a crystalline mineral is known as rock salt or halite. Salt is present in vast quantities in seawater, where it is the main mineral. The open ocean has about 35 grams (1.2 oz) of solids per liter of sea water. This means the salinity of the ocean is of 3.5%.

hypothesis (plural hypotheses) is a proposed explanation. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous observations. 


Experiment One: Dissolving Salt.

  1. Question – Is there a limit to how much salt will dissolve in water?
  2. You have been provided with small containers, salt, measuring spoons, stirrers, and water. How will you answer this question?
  3. Use this Scientific Method Graphic Organiser to plan out your experiment. Complete the first two sections.
  4. Carry out your experiment.
  5. Complete the Scientific Method Graphic Organiser.

Note – when no more salt can be dissolved the solution is saturated.

Session Three – Dissolving Sugar (a, c)

Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. The various types of sugar are derived from different sources. There are simple sugars such as glucose and fructose, and complex sugars such as “Table sugar” which is glucose and fructose joined together.

Using a Control

A control is a standard which is used to compare other things against. Not all science experiments require a control, but many do. You will need to make your own control. Here is an example of a control in a growing experiment:

To find out how plants grow in different types of soil mixtures you would need a control pot. The control pot would use regular potting soil and the same daily routine of water and sun.

The other pots would have different soil mixtures and may be exposed to varying lights and temperatures.

Once the science experiment starts, you would need to document what your control pot is like at every point that you check the other plants. Your control will tell you what effect the other soils and routines have had.



Experiment Two: Dissolving Sugar.

  1. Question – Does sugar dissolve at different rates in different liquids?
  2. You have been provided with a selection of liquids (water, lemon juice, oil, vinegar, soda, hydrogen peroxide) and high sugar content candy. Use whatever equipment you need. The containers should be glass and equal. 
  3. Use this Scientific Method Worksheet to plan out your experiment. Complete the first four sections.
  4. Carry out your experiment and use this Recording Sheet to record what happens. (Note: 1.You do not have to use all the liquids. 2. Do not mix the liquids. 3. You can alter the temperature of the liquids EXCEPT the hydrogen peroxide.)
  5. Completing this activity could take some time so at this point feel free to carry on with something else, but leave the timer going and check back often.
  6. Complete the Scientific Method Worksheet .

Session Four – Evaporating Magnesium Sulfate & Reversal (b, c)

Magnesium sulfate is an inorganic salt with the formula MgSO4(H2O). It is commonly called Epsom salt. Epsom salt has been traditionally used as a component of bath salts. Epsom salt can also be used as a beauty product. Athletes use it to soothe sore muscles, while gardeners use it to improve crops. 

crystal is a solid material whose atoms, molecules, or ions are arranged in a highly ordered microscopic structure. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization.

Experiment Three: Growing Crystals.

  1. Question – Does the temperature of the solvent affect the crystal size and shape?
  2. You have been provided with Magnesium Sulfate (Epsom salt).
  3. You are going to grow 5 batches of crystals.
    • hot water – evaporate at room temperature (this is your control).
    • hot water – evaporate in the fridge.
    • warm water – evaporate at room temperature.
    • cold water – evaporate at room temperature.
    • cold water – evaporate at room temperature – use a seed crystal from a cold water batch.
  4. Use this Scientific Method Worksheet to plan out your experiment. Complete the first four sections.
  5. Carry out your experiment and  record what happens. 
  6. Batches 1 and 2 and 3 should produce crystals within an hour and we will use these results today. The 2 remaining batches will be observed for days to weeks (or beyond!). 
  7. Complete the Scientific Method Worksheet .

Session Five – Filtration of Water. (b, c)

Note: The makers of the video are somewhat uneducated about activated charcoal not being a wonder health treatment because it absolutely is according to many people, but that’s not entirely their fault – they can’t know everything.

Experiment Three: Making Lake Water Clean.

  1. Question – Can murky lake water be made clear and clean?
  2. You have been provided with activated charcoal, soil, and pots.
  3. You will collect lake water.
  4. You are going to make a water filtration system as seen in the second video.
  5. Use these scientific method headings to plan out your experiment. Complete the first four sections.
    1.  Problem
    2. Background Research
    3. Hypothesis
    4. Experiment
    5. Results
    6. Conclusion
  6. Carry out your experiment and  record what happens. 
  7. Complete the write up of your experiment.

Session Six – Wrap up!

Make a cool cover to go with your worksheets and put them all together to make a booklet.

You worked super hard. Relax with a cool video.

Here’s the channel: