Quiz on Pure and Impure Substances & Metal Reactivity

Which of the following best describes a pure substance?

• A substance containing two or more types of atoms chemically bonded

• A substance made of only one type of atom or compound

• A mixture of different elements and compounds

• A solution with dissolved particles

Which of the following is an example of an impure substance?

• Distilled water

• Gold

• Air

• Oxygen gas

Which characteristic distinguishes a pure substance from a mixture?

• Pure substances have variable compositions

• Mixtures have sharp melting and boiling points

• Pure substances have sharp melting and boiling points

• Mixtures contain only one type of atom

What is the main cause of impurities in a chemical reaction?

• Excess reactants

• Low temperature

• Pre-existing impurities in reactants

• All of the above

Which of the following is an example of a solvent?

• Sugar

• Water

• Salt

• Carbon dioxide

What is the term for the number of solute particles dissolved in a solvent?

• Purity

• Concentration

• Dissociation

• Solubility

Why does solubility increase with temperature?

• Solvent particles move slower

• Solid particles vibrate more and spread out

• Less collisions occur

• The solvent becomes denser

What is chromatography used for?

• Separating metals

• Determining boiling points

• Identifying substances in a mixture

• Changing chemical compositions

Which of the following is an application of chromatography?

• Measuring air pressure

• Checking food contamination

• Separating oxygen from nitrogen

• Filtering bacteria from water

Which of the following will show a chromatogram with multiple spots?

• Pure gold

• Distilled water

• Ink from a marker pen

• Table salt