Chemical Reactions unit check for understanding

If you are given the chemical formula C₆H₁₂O₆, how would you determine the total number of atoms in one molecule?

• Add the subscripts: 6 + 12 + 6

• Multiply the subscripts: 6 × 12 × 6

• Subtract the smallest subscript from the largest

• Divide the largest subscript by the smallest

Why are synthetic materials different from natural materials?

• They are made by changing natural substances through a chemical process

• They are always found in nature

• They do not involve any chemical changes

• They are only made from metals

Which of the following best describes when a chemical property can be observed?

• When atoms rearrange during a chemical change

• When the substance is heated

• When the substance is dissolved in water

• When the substance is broken into pieces

Which of the following best describes a synthesis reaction?

• A + B → AB

• AB → A + B

• AB + CD → AC + BD

• Acid + base → salt and water

In a chemical reaction, what do we call the new substances that are formed?

• Reactants

• Products

• Catalysts

• Inhibitors

Which of the following best describes the direction of heat flow in an endothermic reaction?

• Heat flows into the system from the surroundings

• Heat flows out of the system to the surroundings

• Heat flows equally in both directions

• No heat flow occurs

Why is it important to identify reactants and products in a chemical reaction?

• To understand what substances are involved and what changes occur

• To make the reaction faster

• To avoid using any chemicals

• To increase the temperature of the reaction

Which of the following best describes an endothermic reaction?

• The reaction releases heat and feels hot

• The reaction absorbs heat and feels cooler than its surroundings

• The reaction produces light

• The reaction is always explosive

If two or more atoms join together chemically, what do they form?

• Molecule

• Atom

• Element

• Mixture

What is the general formula for a decomposition reaction?

• A + B → AB

• AB → A + B

• AB + CD → AC + BD

• Acid + base → salt and water