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Worksheets0425-W047(H) PURE SUBSTANCES
Total questions: 22
Worksheet time: 30mins
What is a pure substance?
A substance that is always solid
A substance that is always liquid
A substance with only one type of particle
A mixture of elements
Which of the following is an example of a pure substance?
Tap water
Seawater
Air
Silicon
What does the term 'purity' refer to?
The color of a substance
The number of substances in a mixture
The temperature of a substance
The state of matter of a substance
What is the purity of water in 100g of seawater?
100%
50%
96.3%
3.7%
What is the main ingredient in the vaccine mentioned?
Chlorine
Silicon
Water
Ibuprofen
What is the chemical formula for ibuprofen?
NaCl
C13H18O2
C6H12O6
H2O
Why does the vaccine company not use tap water?
It is not available
It contains other substances
It is too cold
It is too expensive
What is the purity percentage of the ibuprofen sold by the chemical company?
75%
90%
98%
100%
Which of the following statements is true about pure water?
It contains other substances
It is a mixture
It contains only water molecules
It is always solid
What are the main differences between pure substances and mixtures?
Mixtures are always gases
Mixtures contain more than one substance
Pure substances are always liquid
Pure substances can be solid
Pure substances only have one type of substance.
How can you show that a substance is pure?
By checking its color
By tasting it
By analyzing its composition
By measuring its temperature
What is the role of silicon in technology?
It is used to make salt
It is used to purify water
It is used to make integrated circuits
It is used to make vaccines
In everyday life, what does 'pure' mean?
Always solid
Contains no elements
Always liquid
Not processed
What is the main component of seawater?
Water
Chlorine
Salt
Silicon
If a substance has a purity of 98%, how much of it is the actual mass of the substance in 100g?
100g
50g
2g
98g
What is the purpose of recording the temperature as the stearic acid cools every minute?
To determine its impurities
To calculate its boiling point
To analyze its conductivity
To identify its melting point
Examine the models on the left.
Which model represents a pure substance?
Model 1,
because it represents compounds.
Model 2, because it represents several elements.
Model 3, because it represents one type of compound.
Model 4, because it contains both elements and compounds.
Group A: Water, Table Salt, Oxygen, Carbon Dioxide
Group B: Salt Water, Air, Milk, Blood
Which of the following best describes the groups?
Group A are mixtures; Group B are solutions
Group A are elements; Group B are mixtures
Group A are pure substances; Group B are mixtures
Group A are compounds; Group B are pure substances
A mixture of sand and metal filings needs to be separated. Which of the following would be the best method of separating them?
filtration
evaporation
chromatography
magnetism
Hydrogen (H) is
a pure substance
a mixture
a compound
a solution
Draw a mixture of 2 different elements and a compound.
