Decomposition Reactions and Quicklime

The video tutorial explains decomposition reactions, contrasting them with combination reactions. It highlights the decomposition of silver bromide under light, used in photography, and the thermal decomposition of calcium carbonate into quicklime, used in cement production. The tutorial concludes by summarizing the characteristics of decomposition reactions, emphasizing their need for energy input and their role as the opposite of combination reactions.

What is a decomposition reaction?

• A reaction that requires no energy input.

• A reaction where a single substance breaks down into two or more substances.

• A reaction that occurs only in the presence of water.

• A reaction where two substances combine to form one.

What happens to silver bromide when exposed to light?

• It combines with oxygen.

• It remains unchanged.

• It forms a new compound with water.

• It decomposes into silver and bromine.

What is the balanced chemical equation for the decomposition of silver bromide?

• AgBr → Ag + Br

• 2AgBr → 2Ag + Br2

• AgBr2 → Ag + Br2

• 2Ag + Br2 → 2AgBr

Which forms of energy can drive decomposition reactions?

• Only electricity

• Only light

• Heat, light, or electricity

• Only heat

What is thermal decomposition?

• Decomposition caused by light.

• Decomposition caused by electricity.

• Decomposition that occurs spontaneously.

• Decomposition caused by heating.

What are the products of the thermal decomposition of calcium carbonate?

• Calcium oxide and carbon dioxide

• Calcium oxide and water

• Calcium carbonate and water

• Calcium and oxygen

What is another name for calcium oxide?

• Marble

• Quicklime

• Limestone

• Chalk

What is the main use of quicklime in industry?

• As a food additive

• In cement production

• As a fuel

• In water purification

What is the opposite of a decomposition reaction?

• A redox reaction

• A displacement reaction

• A combination reaction

• A synthesis reaction

Which of the following is NOT a characteristic of decomposition reactions?

• They require energy input.

• They produce simpler substances.

• They involve a single reactant.

• They always produce heat.