Properties of Water Experiments

Properties of Water Experiments exercise

• Predict what will happen.

  Hints

  Why is it important that the water glass is not on a heater, or near an open window?

  If the water level went up, where did the extra water come from?

  The water will gradually evaporate. What does evaporate mean? Is this a slow process or a fast one?

  Solution

  • The water level will go down slightly every two or three days. You can see this by marking the new level with a permanent marker every two or three days.
  • The reason the water level goes down is due to evaporation.

  It is important that the glass is not near an open window or on a heater, as this will make the water evaporate too quickly to observe.

• What will happen?

  Hints

  The glass should be in the fridge for two to three hours. After you take it out into a warm room, how will the glass feel?

  The glass should be in the fridge, not the freezer.

  Condensation occurs when water vapour in warm air hits a cold surface and turns back into liquid form.

  There are two correct statements and three incorrect.

  Solution

  LIKELY RESULTS

  • The glass and water will be very cold.
  • The glass will have water droplets on the outside after a few minutes.

  FALSE

  • The glass and water will not be at room temperature after two hours in the fridge, because the fridge will be cooler than the room.
  • The glass will not be dry on the outside because of the temperature difference between the water in the glass and the air around it; condensation will occur.
  • The water in the glass will not be frozen because the temperature of a fridge is not cold enough to freeze water.

• Making predictions.

  Hints

  The only way the glass with 100 grams of ice can be empty is if the ice turns into gas and evaporates.

  Although the ice has a larger volume than the liquid water (takes up more space), they both have exactly the same weight.

  There is only one correct choice.

  Solution

  The glass with the original water and the glass with the melted ice will have the same amount of liquid after the ice melts. This is because even though the ice cubes take up more space than the water, the weight is the same. Therefore, the amount of water is the same, even if it is in the form of ice.

• Explain what happened.

  Hints

  The glass of water should not be near an open window or a heat source.

  The glass of water should be in a place where no one and nothing disturbs it.

  There are two correct statements to highlight.

  Solution

  • The liquid in the glass turned into water vapour over time.
  • Water evaporated from the glass making the water level appear lower over time.

• Label the different states of water.

  Hints

  Orange juice, milk and anything you can pour is a liquid.

  Cream is a liquid and ice cream is a solid.

  If you try to touch a gas or water vapour, you may not even feel it; it is often invisible.

  Solution

  The different phases of water are:

  • Solid
  • Liquid
  • Gas (water vapour)

• Explain the result.

  Hints

  Water has three states:

  • Solid (ice)
  • Liquid (water)
  • Gas (water vapour)

  One of the choices is used twice in two separate sentences.

  • When water turns from a solid to a liquid, this is melting.
  • When water turns from a liquid to a gas, this is evaporation.
  • When water turns from a gas to a liquid, this is condensation.

  Solution

  1) The glass became very cold in the fridge. When it was taken out , there was a difference in temperature between the cold glass and the warm air.

  2) There is always water vapour in the air on Earth. This stays in gas form in the warm air.

  3) When the water vapour in the warm air hits the cold glass, it condenses and turns into liquid form.

  4) The water droplets on the outside of the glass are actually condensed water vapour from the air outside the glass!