WorksheetsTerm2_Pastpaper
Total questions: 25
Worksheet time: 1hrs 15mins
Iron + oxygen --> __________________________
Complete the word equation.
Iron oxide
Oxide Iron
Iron + oxygen
Iron + oxide
copper carbonate --> copper oxide + carbon dioxide.
Name the reactant in this reaction.
Reactant_____________________________________
Copper oxide, carbon dioxide
Carbon dioxide
Copper carbonate
Copper
Identify the following diagram.
FIRE TRIANGLE
FIRE WARNING
HEATING TRIANGLE
NON OF ALL
The following word equation represents a natural endothermic reaction.
Identify and write the name of this reaction.
Respiration reaction
photosynthesis reaction
In the figure given below, colourless lead nitrate solution is reacting with colourless potassium iodide solution to produce a yellow solid of lead iodide.
This reaction is called
Endothermal Reaction.
Decomposition Reaction
Precipitation reaction
Exothermal reaction
Complete the following sentence.
If a chemical reaction is ________________, the temperature of the surroundings would INCREASES.
This reaction is called
Endothermal Reaction.
Decomposition Reaction
Precipitation reaction
Exothermal reaction
State whether the following statement is true or false:
After a chemical reaction it is very difficult,
or impossible, to get the starting materials back again._
True
False
What kind of change is shown by tearing of paper?
Physical Change
Chemical Change
A chemical change may involve ______________________________
change in colour only
change in temperature only
evolution of gas only
any or all of the above
What does the arrow (-->) mean in a word equation?
are the same as
are equal to
react to make
join up to make
Bubbles of gas are produced when baking soda reacts with vinegar.
Name the gas formed in this chemical reaction.______________________
carbon dioxide
hydrogen
oxygen
nitrogen
Magnesium burned brightly in the air by reacting with oxygen in the air to form magnesium oxide.
Identify the reactant/s in this reaction.
magnesium and oxygen
magnesium oxide
magnesium
magnesium oxide and oxygen
Which of the following is not an example of an exothermic chemical reaction?
melting of ice cube
burning a piece of wood
freezing water into ice
respiration
Evaporation is an endothermic reaction because _______________________.
heat energy is absorbed causing the water molecules to vibrate more and escape the surface.
heat energy is given out as the molecules escape the surface.
the motion of the molecules slows down.
the water molecules break to form oxygen and hydrogen.
Paheli’s mother made concentrated sugar syrup by dissolving sugar in hot water.
On cooling, crystals of sugar got separated.
This indicates a __________________________.
a physical change that can be reversed.
the chemical change that can be reversed.
a physical change that cannot be reversed.
the chemical change that cannot be reversed.
Which of the following statement is incorrect for a chemical reaction?
Heat may be given out but never absorbed.
The sound may be produced.
A colour change may take place.
A gas may be evolved.
An experiment shows that hydrogen peroxide decomposes to form water and oxygen gas.
Which of the following word equations describes the chemical reaction that has occurred in this experiment?
hydrogen peroxide --> water + oxygen
hydrogen peroxide + oxygen --> water
hydrogen peroxide --> water + hydrogen
hydrogen peroxide + water --> oxygen
A piece of magnesium is dropped into a test-tube containing dilute hydrochloric acid.
Why do the test-tube become warm?
Hydrogen is produced.
The magnesium neutralizes the acid.
The reaction is endothermic.
The reaction is exothermic.
CNG and LPG are the examples of ___________________
solid fuels
liquid fuels
gaseous fuels
they are not fuels
An ideal fuel must have certain characteristics. Which of the following is NOT a characteristic of an ideal fuel?
high calorific value
burns at moderate rate
products of combustion are harmful
readily available
A steel bicycle which had been left outdoors for several months was starting to rust.
What would not reduce the rate of corrosion?
Remove the rust and paint the bicycle.
Remove the rust and store the bicycle in a dry shed.
Remove the rust and wipe the bicycle with a clean, damp cloth.
Remove the rust and wipe the bicycle with an oily cloth.
The diagram shows a method of preventing rusting.
This method of preventing rusting is called ________________________________.
sacrificial protection
electroplating
plastic coating
greasing
The diagram below shows experiments involving the rusting of iron.
In which test-tubes do the nails rust?
1 only
1 and 2 only
1 and 3 only
2 and 3 only
Galvanisation is a process used to prevent the rusting of iron.
During Galvanisation iron is coated with ________________ to prevent rusting.
silver
zinc
aluminium
copper
Why does a bicycle chain that is coated with oil not rust?
Oil dissolves any rust that forms.
Oil reacts with rust causing oxidation.
Oil reacts with oxygen so no rust forms.
Oil stops oxygen and water getting to the chain.
