Chemical Equations and Reactions: The Chemical Reactions

The lesson covers three types of combination reactions: between two elements, between an element and a compound, and between two compounds. It highlights the benefits of chemical reactions, such as energy production and industrial applications, and the environmental harm they can cause, like pollution. The lesson concludes with the representation of chemical reactions through equations, detailing reactants, products, and conditions.

Which of the following is an example of a combination reaction between two elements?

• Ammonia and hydrochloric acid forming ammonium chloride

• Sulfur dioxide and water forming sulfurous acid

• Hydrogen and oxygen forming water

• Oxygen and carbon monoxide forming carbon dioxide

Which of the following is NOT a type of combination reaction?

• Between two compounds

• Between an element and a compound

• Between two elements

• Between a compound and a mixture

What is a benefit of chemical reactions in industries?

• They are only used in the food industry

• They convert more useful substances into less useful ones

• They can produce electric and heat energy

• They always produce harmful gases

Which of the following is a harmful effect of chemical reactions?

• Generation of renewable energy

• Formation of water

• Environmental pollution

• Production of oxygen

How can chemical reactions be represented?

• Through physical models

• By using chemical equations

• With verbal descriptions only

• By drawing pictures