Stoichiometry Review

What is percent yield?

• A measure of the total amount of reactants used in a reaction.

• A measure of the efficiency of a chemical reaction, calculated as the ratio of the actual yield to the theoretical yield, multiplied by 100.

• The percentage of a product that is lost during a chemical reaction.

• A calculation of the maximum possible yield of a reaction based on the limiting reactant.

What is the role of a limiting reactant in a chemical reaction?

• It is the substance that is completely consumed first in a reaction, limiting the amount of product formed.

• It is the reactant that is present in excess and does not limit the reaction.

• It is the product formed in the reaction that determines the reaction rate.

• It is the catalyst that speeds up the reaction without being consumed.

How can the concentration of a mixture be increased?

• By adding more solute (e.g., powder) to the mixture.

• By diluting the mixture with more solvent.

• By increasing the temperature of the mixture.

• By reducing the volume of the mixture.

What is the first step in solving a stoichiometry problem?

• Write a balanced chemical equation.

• Measure the mass of the reactants.

• Calculate the molar mass of the products.

• Determine the limiting reactant.

Define mole ratio.

• Mole ratio is the ratio of the coefficients of any two substances in a balanced chemical equation, used to convert between moles of reactants and products.

• Mole ratio is the total number of moles of all substances in a reaction.

• Mole ratio is the ratio of the mass of reactants to products in a chemical reaction.

• Mole ratio is the number of moles of a single substance in a reaction.

What is the effect of temperature on reaction rates?

• Increasing temperature decreases reaction rates by reducing energy to the reactants.

• Increasing temperature generally increases reaction rates by providing more energy to the reactants, leading to more frequent and effective collisions.

• Temperature has no effect on reaction rates.

• Increasing temperature only affects solid reactants, not liquids or gases.

What is the significance of stoichiometry in chemistry?

• Stoichiometry allows chemists to predict the quantities of reactants and products involved in chemical reactions.

• Stoichiometry is used to measure the temperature of chemical reactions.

• Stoichiometry helps in determining the color of chemical compounds.

• Stoichiometry is a method for balancing chemical equations.

What is the importance of a balanced equation in stoichiometry?

• It allows for the calculation of energy changes in reactions.

• It provides the mole ratios needed to calculate reactants and products.

• It simplifies the reaction mechanism for better understanding.

• It determines the color change during a reaction.

How do you determine the limiting reactant?

• By comparing the mole ratios of the reactants to the coefficients in the balanced equation.

• By calculating the total mass of the reactants used.

• By measuring the temperature change during the reaction.

• By observing the color change of the reactants.

What is the formula for calculating percent yield?

• Percent yield = (Actual Yield / Theoretical Yield) x 100.

• Percent yield = (Theoretical Yield / Actual Yield) x 100.

• Percent yield = (Actual Yield + Theoretical Yield) x 100.

• Percent yield = (Actual Yield - Theoretical Yield) x 100.