Limiting Reactant and Excess Definitions

What is a limiting reactant?

• The substance that is added in excess in a chemical reaction

• The substance that has the highest concentration in a chemical reaction

• The substance that is not involved in a chemical reaction

• The substance that is completely consumed in a chemical reaction, limiting the amount of product that can be formed.

Tags

NGSS.HS-PS1-7

How do you determine the limiting reactant in a chemical reaction?

• By comparing the moles of each reactant to the balanced chemical equation and identifying which one produces the least amount of product.

• By flipping a coin and choosing the reactant that lands face up

• By selecting the reactant with the longest chemical name

• By asking a friend to guess which reactant is the limiting one

What is an excess reactant?

• The reactant that inhibits a chemical reaction from occurring

• The reactant that is present in a greater quantity than necessary for a chemical reaction to occur.

• The reactant that is completely consumed in a chemical reaction

• The reactant that is not necessary for a chemical reaction to occur

How is the amount of excess reactant calculated in a chemical reaction?

• By adding the amount of product formed to the initial amount of reactant.

• By multiplying the amount of product formed by the initial amount of reactant.

• By dividing the amount of product formed by the initial amount of reactant.

• By subtracting the amount of reactant that actually reacted from the initial amount of reactant.

What is the purpose of identifying the limiting reactant in a chemical reaction?

• To determine the color of the product

• To determine the maximum amount of product that can be formed

• To identify the catalyst

• To speed up the reaction

Tags

NGSS.HS-PS1-6

NGSS.HS-PS1-7

What is the theoretical yield in a chemical reaction?

• The maximum amount of product that can be obtained from a given amount of reactants

• The minimum amount of product that can be obtained from a given amount of reactants

• The amount of reactants needed to produce a given amount of product

• The average amount of product that can be obtained from a given amount of reactants

How is the theoretical yield calculated?

• By guessing and estimating

• Using the stoichiometry of the balanced chemical equation and the amount of limiting reactant.

• By using the color of the reaction mixture

• By flipping a coin and making a prediction

Tags

NGSS.HS-PS1-7

What is the actual yield in a chemical reaction?

• The temperature of the reaction

• The color of the reactants

• The amount of product obtained from a reaction

• The speed of the reaction

How is the percent yield calculated in a chemical reaction?

• Actual yield - Theoretical yield * 100

• Actual yield / Theoretical yield * 100

• Actual yield + Theoretical yield * 100

• Actual yield * Theoretical yield / 100

Tags

NGSS.HS-PS1-7