WorksheetsEnergy and Chemical Changes
Total questions: 15
Worksheet time: 9mins
A chemical change is different than a physical change because in a chemical change...
Chemicals are used
Molecules do not physically touch
A new substance is formed and in a physical change no new substance is formed
The change can be seen but in a physical change it cannot
If two substances react and the temperature of the mixture increases, the reaction is
Not one that produces anything new
Exothermic
One that needs a catalyst
Endothermic
If two substances react and the temperature of the mixture decreases, the reaction is
Endothermic
Never going to happen unless it is heated
Exothermic
one that causes atoms to be destroyed
What is a sign of a physical change?
odour produced
change in state of matter
light
temperature change
What is a sign of a chemical change?
change in state of matter
change in size
change in shape
temperature change
Aluminium is more reactive than ....
Calcium and Zinc
Sodium and Gold
Magnesium and Copper
Lead and Iron
Based on the following diagram, what is the function of potassium manganate (VII) crystals in this experiment?
To supply oxygen
To avoid the metals to mix with each other
To release heat
To give out water vapour
Complete the word equation below.
Magnesium + oxygen --> .....
Magnesium
Magnesium oxide
Oxides
Magnesium oxide + water
When aluminium oxide react with carbon, there is no change that will occur. What is your inference for this observation?
Carbon cannot remove the oxygen from the aluminium oxide
Carbon is less reactive than aluminium
Aluminium is more reactive than carbon
All of the above
The negatively charged ions are attracted to the ________.
anode
cathode
If the fork is to be electroplated with silver metal, what electrolyte should be used?
Molten silver chloride
Silver nitrate solution
Sodium chloride solution
Copper(II) sulphate solution
Name a metal that could be extracted from its metal oxide by heating with carbon.
tin
aluminium
calcium
magnesium
