Ch. 7 Review

All of the following factors may speed up a chemical reaction except

• smaller surface area
• higher pressure
• higher temperature
• presence of a catalyst

Which of these is not a sign of a chemical reaction?

• A gas is given off
• the material dissolves
• heat is released
• a color change

The substance that is formed in a chemical reaction is called the

• polymer
• reactant
• radical
• product

Which of the following stores chemical energy?

• the temperature of a substance
• the density of a substance
• the bonds of a molecule
• the nucleus of an atom

Which of the following occurs in an endothermic reaction but not in an exothermic reaction?

• chemical bonds are broken
• energy is absorbed
• molecules are formed
• atoms are rearranged

A type of reaction that produces an increase in temperature is

• endothermic
• exothermic
• covalent
• nonpolar

In a balanced chemical equation, the mass of the reactants is equal to the

• atoms in a molecule
• atomic mass of the elements
• volume of the reactants
• mass of the products

What coefficient is missing in N₂ + ?H_{2 ->} 2NH₃?

• 2
• 3
• 4
• 5

Which of the following represents the word equation magnesium + oxygen -> magnesium oxide?

• CH₄+ O₂ -> CH₄O₂
• MgO + O -> MgO₂
• 2Mg + O₂ -> 2MgO
• 2CH₄ + O₂ -> 2CH₃OH

Which of the following equations is not balanced?

• Fe + S-> FeS
• KOH + HCl -> KCl + H₂O
• 2Mg + O₂ -> 2MgO
• NaCl + H₂SO₄ -> Na₂SO₄ + HCl