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WorksheetsS2 - Chemistry Block 1 Revision
Total questions: 23
Worksheet time: 12mins
Which of these are an example of a chemical reaction?
Making some toast
Boiling water
Melting iron
Making a cup of tea with sugar
Chemical reactions are ___________?
Irreversible
Reversible
What sign of a chemical reaction will be seen in this experiment?
A gas will be made
A precipitate will be made
Heat will be released
It will be endothermic
Which of these is a sign of a chemical reaction?
Iron wool becomes lighter when burned
Two liquids mixed together make a precipitate
Zinc metal is melted to form electronics solder
Salt is added to water
A precipitate being made is a sign of a chemical reaction, what is it?
A insoluble solid formed when two liquids are mixed together
When a clear liquid becomes coloured
When a gas is made
When a reaction is endothermic
What signs of a chemical reaction are there when a sparkler is used?
Heat
Light
Gas made
Precipitate made
An exothermic reaction is one where heat is?
Heat released
Heat taken in
An endothermic reaction is one where heat is?
Heat released (it is hot)
Heat taken in (it is cold)
Burning wood is an example of a exothermic or endothermic reaction?
Exothermic
Endothermic
Physical changes are ___________?
Irreversible
Reversible
Dissolving is an example of a?
Physical change
Chemical reaction
A reaction rate is the?
how quickly the chemical reaction happens
chemicals which are made in a chemical reaction
chemicals which take part in a chemical reaction.
how quickly the physical change happens
What are the four ways a chemical reaction can be sped up?
Temperature, particle size, concentration, catalyst
Temperature, particle size, dilution, catalyst
Temperature, particle size, dilution, precipitation
Endothermic, particle size, concentration, catalyst
In which beaker will the rate of reaction be fastest?
Left beaker with low surface area
Right beaker with high surface area
Higher temperatures speeds up chemical reaction because?
The particles move faster as they have lots of energy
The particles move slower as they have lots of energy
The particles are warmer and easier to melt together
In which beaker will the rate of reaction be fastest?
Left beaker with low concentration
Right beaker with high concentration
Catalysts speed up chemical reactions, are they used up during the reaction?
Yes
No
What is an enzyme?
A biological catalyst
A chemical
A chemical catalyst
A reactant
A Bunsen burner burns with a much hotter flame if the hole is open, why?
There is a higher concentration of oxygen
There is more airflow
There is more gas
There is a higher concentration of carbon dioxide
You’re planning an experiment comparing particle size of chalk when reacted with sulphuric acid.
List three variables that would need to be kept constant for this to be a valid experiment.
Mass of chalk
Volume of acid
Temperature
Oxygen concentration
Presence of catalyst
Which of these is a valid/fair experiment?
lumps of chalk reacting with 10 cm3 of acid at 20oC and powder of chalk reacting with 20 cm3 of acid at 20oC
curing resin at 50oC for 15 minutes and curing resin at 5oC for 10 minutes
lumps of chalk reacting with 10 cm3 of acid at 20oC and powder of chalk reacting with 10 cm3 of acid at 20oC
lithium powder with 50% acid and lithium lump with 25% acid.
Homemade sparklers react as follows:
Iron + Oxygen -----> Iron Oxide
What do you call the chemicals to the left of the arrow?
Reactants
Products
Starting chemicals
Raw chemicals
Which of the below will not speed up a reaction?
Decreasing the temperature
Increasing the concentration of the chemicals
Adding a catalyst
Increasing the particle size
