G9-Q4-Worksheet 3

What does a chemical equation represent?

• A) Only the products
• B) Only the reactants
• C) The physical properties of substances
• D) The reactants and products of a chemical reaction

Which of the following is NOT provided by a word equation?

• A) Reactants
• B) Products
• C) Number of atoms
• D) Names of substances

Which symbol indicates a substance in liquid state?

• A) (g)
• B) (l)
• C) (s)
• D) (aq)

In the skeleton equation: H₂(g) + Br₂(g) → HBr(g), which type of substances are involved?

• A) Solids
• B) Liquids
• C) Gases
• D) Aqueous solutions

What is the correct skeleton equation for the reaction of hydrogen and bromine?

• A) H + Br → HBr
• B) H₂(g) + Br₂(g) → HBr(g)
• C) H₂ + Br → HBr
• D) H₂(g) + Br(g) → H₂Br(g)

What is added to balance a chemical equation?

• A) Subscripts
• B) Products
• C) Coefficients
• D) Atoms

Which of the following is NOT a step in balancing equations?

• A) Change coefficients
• B) Check your work
• C) Add more products
• D) Count atoms

What kind of reaction takes in energy from the surroundings?

• A) Endothermic
• B) Exothermic
• C) Static
• D) Catalytic

What does an exothermic reaction do?

• A) Lowers energy
• B) Absorbs energy
• C) Releases energy
• D) None of the above

Which of the following best defines a coefficient in a chemical equation?

• A) A subscript in a formula
• B) A letter indicating phase
• C) A number in front of a compound
• D) An ion in the reaction