Unit 5_Categories of Chemical Reactions

During a science experiment, Eric mixed two clear liquids together and noticed that a gas started to form. What is a characteristic that indicates a chemical reaction has occurred?

• Formation of a solid without a reaction

• Formation of a gas

• Temperature increase

• Change in color

Celine and Honnette are mixing different ingredients in the kitchen. What type of reaction occurs when they combine two or more ingredients to create a single dish?

• Decomposition reaction

• Single displacement reaction

• Double displacement reaction

• Synthesis reaction

During a chemistry experiment, Henry combined various substances in a beaker. In a combination reaction, what can the reactants include?

• Only elements

• Only compounds

• Mixtures of gases

• Elements and compounds

During a science experiment, Sophia mixed two solutions together and observed the formation of an insoluble solid. What is this solid called?

• Precipitate

• Emulsion

• Mixture

• Solution

During a science experiment, Chania observed that a compound she mixed began to break down into simpler substances. What type of reaction is she witnessing?

• Synthesis reaction

• Decomposition reaction

• Double displacement reaction

• Single displacement reaction

Gasabato is conducting an experiment where he mixes different elements to see how they react. He notices that when he adds zinc to a solution of copper sulfate, the zinc replaces the copper in the compound. What type of reaction is occurring in this scenario?

• Double replacement reaction

• Synthesis reaction

• Combustion reaction

• Single replacement reaction

During a science experiment, Lyra and Baraka mixed two solutions together. What is the result of a double displacement reaction?

• The result is the release of gas only.

• The result is the formation of a solid only.

• The result is the breakdown of a single compound.

• The result is the formation of two new compounds.

During a science experiment, Nshuti observed the burning of methane (CH₄) in oxygen to produce heat and light. What type of reaction is this an example of?

• Combustion of methane (CH₄).

• Dissolving sugar in water.

• Photosynthesis in plants.

• Rusting of iron in moisture.

Charlotte is conducting an experiment where she mixes vinegar and baking soda. As she observes the reaction, she notices that the temperature of the mixture changes. How can this change in temperature indicate a chemical reaction?

• A change in temperature indicates a chemical reaction by showing heat release or absorption.

• Temperature changes only occur in physical changes, not chemical reactions.

• Chemical reactions always result in a temperature decrease.

• Temperature change is unrelated to chemical reactions.

Kelia is conducting an experiment where she mixes vinegar and baking soda in a container. As she observes the reaction, she notices bubbles forming and the temperature rising. What happens to the state of matter in this chemical reaction?

• The state of matter is irrelevant to chemical reactions.

• Chemical reactions only involve changes in temperature, not state of matter.

• The state of matter can change during a chemical reaction.

• The state of matter remains unchanged in a chemical reaction.