Quiz on Principles of Chemistry

What is an element?

• A mixture of different compounds

• A solution of a solute in a solvent

• A substance made from only one type of atom

• A substance made from two or more elements

What is a characteristic of a pure substance?

• It can melt or boil over a range of temperatures

• It has a fixed melting and boiling point

• It consists of two or more elements

• It is always a solid at room temperature

What is a mixture?

• A substance that has a fixed melting point

• A substance made from only one type of atom

• A combination of two or more substances that are not chemically combined

• A compound formed by chemical reaction

Which of the following describes a compound?

• A pure substance with a fixed boiling point

• A substance made from two or more elements that have reacted chemically

• A substance made from only one type of atom

• A mixture of two or more elements not chemically combined

Which technique is used to separate a solvent from a solution?

• Crystallisation

• Filtration

• Fractional distillation

• Simple distillation

What does fractional distillation separate?

• A solid from a liquid

• A pure liquid from a mixture of liquids

• A mixture of solids

• A gas from a liquid

What is the purpose of filtration?

• To identify components in a mixture

• To separate a precipitate from a solution

• To separate different liquids based on boiling points

• To separate a soluble salt from a solution

What happens during crystallisation?

• A solid dissolves in a liquid

• A mixture is heated to separate components

• A liquid evaporates to leave a solid

• A gas is cooled to form a liquid

What does paper chromatography separate?

• Gases from liquids

• Solids from liquids

• Different pigments in a coloured substance

• Mixtures of solids

What does an Rf value represent?

• The distance moved by a substance relative to the solvent

• The melting point of a compound

• The distance moved by the solvent

• The boiling point of a substance