Changes of State: Water Worksheet

This worksheet tests your understanding about the three states of matter when applied to water.

Water

For example: what is solid water, what has to be done to it to turn it to liquid water? What is "water gas" called and can it become liquid water again? Does the outside temperature and pressure matter? These are some of the aspects of water we'll be exploring.

Is this statement true or false?

The process by which plants give off water vapour is known as perspiration.

true

false

Is this statement true or false?

The rate of evaporation depends on the amount of exposed surface area of the leaf.

true

false

Complete this sentence.

When salt is added to ice, the freezing point of the ice __________.

increases

decreases

remains the same

keeps changing

Complete this sentence.

The rate of evaporation of a glass of water would be highest when the ____________.

water is cold

humidity is high

glass is warmed

glass is covered over at the top by cling film

Complete this sentence.

For water to have a definite shape and size, it must ___________.

be in a container

become steam

be distilled

become ice

Is this statement true or false?

Ice can be changed into water vapour without first becoming water.

true

false

Which is the right statement about water at 0° C?

It is the melting point of ice and freezing point of water.

It is the freezing point of ice and subliming point of water.

It is the freezing point of ice and melting point of water.

Complete this sentence. Tick two options.

Water freezes at 0° C and boils at 100° C. This statement is only true __________.

at sea level

in a laboratory

at any place on Earth

when the water is pure

Is this statement true or false?

When clouds fall as rain, condensation has taken place.

true

false

Is this statement true or false?

We give off water vapour through the pores on our skin.

true

false

ANSWERS

Question 1

Is this statement true or false?

The process by which plants give off water vapour is known as perspiration.

CORRECT ANSWER

false

EDDIE SAYS

The correct answer is that plants give off water vapour by the process of transpiration. Perspiration is another name for sweating.

ANSWERS

Question 2

Is this statement true or false?

The rate of evaporation depends on the amount of exposed surface area of the leaf.

CORRECT ANSWER

true

EDDIE SAYS

Yes, this is generally correct. However, many leaves have their surfaces covered by a waxy cuticle that makes it impossible for evaporation to take place on that surface. To give a more precise answer, the rate of evaporation depends upon the number of stomata that are open on that leaf. Whether they are open or closed is also multifactorial, but is largely dependent of whether the leaf is in light or not.

ANSWERS

Question 3

Complete this sentence.

When salt is added to ice, the freezing point of the ice __________.

CORRECT ANSWER

decreases

EDDIE SAYS

When ice has salt added to it, then the freezing point goes down. If the temperature is higher than that, then the ice melts. This is why salt is added to icy roads.

ANSWERS

Question 4

Complete this sentence.

The rate of evaporation of a glass of water would be highest when the ____________.

CORRECT ANSWER

glass is warmed

EDDIE SAYS

The rate of evaporation is dependent on the amount of energy provided by the environment, as long as the humidity is low enough for evaporation to take place.

ANSWERS

Question 5

Complete this sentence.

For water to have a definite shape and size, it must ___________.

CORRECT ANSWER

become ice

EDDIE SAYS

The only way that water can have a shape and size is for it to be frozen, but even here ice does alter in shape as it is formed. This is why we get frozen water pipes if our houses get too cold.

ANSWERS

Question 6

Is this statement true or false?

Ice can be changed into water vapour without first becoming water.

CORRECT ANSWER

true

EDDIE SAYS

Have you ever noticed that snowmen can begin to disappear even though the temperature has not risen above zero? This is because in dry conditions ice can turn directly into water vapour without becoming a liquid. This process is called sublimation.

ANSWERS

Question 7

Which is the right statement about water at 0° C?

CORRECT ANSWER

It is the melting point of ice and freezing point of water.

EDDIE SAYS

Water freezes at 0 degrees and ice melts at the same temperature.

ANSWERS

Question 8

Complete this sentence. Tick two options.

Water freezes at 0° C and boils at 100° C. This statement is only true __________.

CORRECT ANSWER

at sea level
when the water is pure

EDDIE SAYS

Water has to be pure to change state at those temperatures. It also has to be at standard pressure, nominally 1 atmosphere, or 760 mm Mercury. If the air pressure is different from this, then the temperature needed to boil water drops. It is impossible to make a decent cup of tea on top of Mount Everest as water boils there when it is only lukewarm!

ANSWERS

Question 9

Is this statement true or false?

When clouds fall as rain, condensation has taken place.

CORRECT ANSWER

true

EDDIE SAYS

Yes, the falling of any sort of precipitation (rain, snow or sleet) involves the condensation of water vapour into water as liquid or solid.

ANSWERS

Question 10

Is this statement true or false?

We give off water vapour through the pores on our skin.

CORRECT ANSWER

false

EDDIE SAYS

This is a rather picky question. We actually sweat liquid water, so water vapour does not come out through our pores. Once on the surface of the skin, it then evaporates.