Chemical Reactions

What does → signify?

• "and"

• "yields/produces"

• Catalyst

• Add heat

What does (g) stand for?

In an exothermic reaction, heat is

• Absorbed

• Released

• Destroyed

• Conserved

Numbers that precede (come before) symbols and formulas in a chemical equation are

• Subscripts

• Superscripts

• Coefficients

• Fractions

Each of the substances to the left of the arrow in a chemical equation is a

• Catalyst

• Product

• Reactant

• Coefficient

What does (aq) designate?

In a combustion reaction between a hydrocarbon and oxygen, the products are always?

• A synthesis reaction

• Carbon dioxide and water

• Oxygen

• Hydrogen, carbon and oxygen

Which of the following types of reactions results in a single product?

• A synthesis reaction

• A decomposition reaction

• A combustion reaction

• A single replacement reaction

• A double replacement reaction

In a chemical reaction, the total mass of the substances before the reaction compared to the total mass of the substances after the reaction is

• Usually smaller

• Usually greater

• Equal

• Sometimes greater, sometimes smaller

What type of reaction is the following?2KI + Pb(NO₃)₂ → PbI₂ + 2KNO₃

• Synthesis

• Decomposition

• Single-replacement

• Double-replacement

• Combustion

What type of reaction is the following?Cl₂ + 2NaBr → 2NaCl + Br₂

• Synthesis

• Decomposition

• Single-replacement

• Double-replacement

• Combustion

In a double-replacement reaction

• The reactants are usually one metal and one nonmetal

• One of the reactants is often water

• The reactants are generally two ionic compounds

• Energy is always produced

What coefficients would be added to balance the following equation?Fe + O₂ → Fe₂O₃

• 2, 3, 1

• 4, 3, 2

• It is already balanced

• You wouldn't add a coefficient you would just change the subscripts

Which of the following is a word equation?

• Sodium oxide → sodium + oxygen

• Sodium oxide decomposes to form sodium and oxygen

• Na2O → Na + O2

• 2Na2O → 4Na + O2

An insoluble substance formed from two solutions is a

• Reactant

• Precipitate

• Compound

• Product

Which of the following is NOT an observable clue that a chemical reaction has occurred?

• Release of a gas

• Odor change

• Precipitate formation

• Mixing two reactants

In a combustion reaction, ______________ is always one of the reactants.

• O

• O2

• CO2

• H2O

Which compound would decompose to form Mg and O₂?

• MgO2

• MgO

• Mg2O2

• Mg and O2

What type of reaction is the following?CH₄ + 2O₂ → CO₂ + 2H₂O

• Synthesis

• Decomposition

• Single replacement

• Double replacement

• Combustion

In order for the reaction F₂ + NaCl → Cl₂ + NaF to occur, which of the following must be true?

• F must be above Na on the activity series

• F must be above Cl on the activity series

• Na must be above F on the activity series

• Cl must be above F on the activity series

What coefficients would balance the following equation?Sr + H₂O → Sr(OH)₂ + H₂

• 1, 4, 2, 2

• 2, 4, 2, 4

• 1, 2, 1, 1

• It is already balanced

What would be the products of the following decomposition reaction?LiCl →

• Li + Cl

• LiCl

• Li + Cl2

• None of the above

Among the elements listed, which could replace all of the rest in a single replacement reaction?

• Li

• Mg

• Cu

• Ag

• Ba