Limiting-Reactant Stoichiometry Concepts

What does the law of conservation of mass state about matter during a chemical reaction?

• Matter is destroyed but can be recreated.

• Matter is created and destroyed.

• Matter can neither be created nor destroyed.

• Matter is only transformed from one type to another.

Which type of reaction involves two substances combining to form a new product?

• Single displacement reaction

• Combination reaction

• Combustion reaction

• Decomposition reaction

In a combustion reaction, what are the typical products when a hydrocarbon reacts with oxygen?

• Water and carbon dioxide

• Oxygen and hydrogen

• Carbon dioxide and hydrogen

• Water and carbon monoxide

What is the result when a single displacement reaction occurs?

• Two compounds exchange ions.

• A compound breaks into simpler substances.

• Two elements combine to form a compound.

• One element replaces another in a compound.

How does the concept of limiting reactants affect the outcome of a chemical reaction?

• It determines the maximum amount of product that can be formed.

• It has no effect on the reaction outcome.

• It increases the speed of the reaction.

• It decreases the amount of energy released.

What is the numerical value of Avogadro's number used in mole calculations?

• 3.141 * 10^23

• 9.81 * 10^23

• 6.022 * 10^23

• 2.718 * 10^23

In a stoichiometric calculation, if you begin with 1.57 moles of oxygen, how many moles of water can be theoretically produced?

• 0.785 moles

• 3.14 moles

• 1.57 moles

• 6.28 moles

Which of the following is not a direct application of stoichiometry?

• Predicting product amounts in reactions

• Determining the limiting reactant

• Calculating the speed of a chemical reaction

• Converting grams of one substance to grams of another

What does a balanced chemical equation not typically indicate?

• Physical states of compounds

• Energy changes during the reaction

• Relative number of moles of reactants and products

• Reaction conditions like temperature and pressure

What is the primary reason actual yields are often less than theoretical yields?

• Calculation errors

• Limiting reactants

• Side reactions or incomplete reactions

• Excess reactants