IB Docs (2) Team MC test: Nature of matter & chemical change
Multiple choice test on 1.1 Introduction to the particulate nature of matter and chemical change
Use the following 'quiz' to test your knowledge and understanding of this sub-topic. You will need access to a periodic table (Section 6 of the IB data booklet).
If you get an answer wrong, read through the explanation carefully to learn from your mistakes.
Which equation correctly describes the reaction that occurs when sodium metal is added to water at room temperature?
The equation must be correct stoichiometrically (i.e. balanced). The equation must also have the correct state symbols. Sodium is a solid, water is a pure substance (so is a liquid at room temperature), sodium hydroxide is in aqueous solution and hydrogen is a gas.
Which of the following are homogenous mixtures?
I. solid steel
II. an aqueous solution of salt
III. molten salt
For a mixture to be homogeneous there must be no clear boundary between the phases of the individual components. Molten salt is a pure substance so is not a mixture. Steel is an alloy so contains carbon (and other metals) as well as iron so both I and II are mixtures and exist in a single phase and so are homogeneous.
Sodium is a metal and chlorine is a green non-metal. They react together to form sodium chloride, NaCl. What can be deduced correctly about the physical properties of solid sodium chloride?
Sodium chloride is a compounds formed from two elements. Compounds have different properties to the elements from which they are derived. Semi-metals (such as silicon and germanium) are elements not compounds.
Which of the following is an element?
If you are an ancient Greek then air and ice (water) would be acceptable answers, but chemical elements must consist of atoms which all contain the same number of protons (i.e. identical atoms if we ignore the concept of isotopes). Air is a homogeneous mixture of different gases, ice (water) is a compound of hydrogen and oxygen and methane is a compound of carbon and hydrogen. Ozone, O3 is an allotrope of oxygen but it only contains oxygen atoms so it is an element.
Which mixture can best be separated into its separate components by using chromatography?
Simple paper chromatography can be used to separate the different colours found in black ink. Air is best separated by fractional distillation, and both sea water and sodium hydroxide solution by distillation.
Which reaction involves precipitation?
For precipitation to occur a solid must be formed from a solution. Only two of the equations have solid products and only in one of them is the solid formed from solution.
What is the sum of all the coefficients when the equation for the combustion of ethanol is balanced using the smallest possible whole numbers?
−C2H5OH(l) + −O2(g) → −CO2(g) + −H2O(l)
The correctly balanced equation is C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l) which gives a total of 9.
Argon, carbon dioxide, oxygen and nitrogen are all present in air. What is the order in which the gases will be formed when liquid air is slowly warmed?
| Gas | Boiling point / oC |
| Ar | − 186 |
| CO2 | − 78 |
| O2 | − 183 |
| N2 |
− 196 |
The liquid with the lowest boiling point will be the first to form a gas so nitrogen gas will be formed first and carbon dioxide last. The boiling point of argon is lower than oxygen so argon will vaporise before oxygen.
At high altitude snow can sublime. Which statement correctly describes this process?
Sublimation occurs when a solid turns directly into a gas.
Which is the correct order for the coefficients in the balanced equation for the reaction between ammonia and oxygen to form nitrogen oxide and water
−NH3(g) + −O2(g) → −NO(g) + −H2O(g) ?
The correctly balanced equation is 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)
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