Chemical Reaction Rates and Measurements

What is reaction rate in chemistry?

• The speed at which reactants transform into products.

• The total amount of products formed in a reaction.

• The energy released or absorbed during a reaction.

• The temperature change observed during a reaction.

What does the reaction rate specifically measure?

• How quickly reactants change into products.

• The final concentration of reactants.

• The initial concentration of products.

• The equilibrium constant of a reaction.

In general, how can the rate of a chemical reaction be measured?

• By observing color changes only.

• By measuring the temperature of the reaction.

• By calculating the activation energy.

• By measuring how quickly reactants decrease or products increase.

What happens to the amount of reactants as a chemical reaction proceeds?

• They increase in concentration.

• They decrease in concentration.

• They remain constant throughout the reaction.

• They transform into catalysts.

What happens to the amount of products as a chemical reaction proceeds?

• They increase in concentration.

• They decrease in concentration.

• They remain constant throughout the reaction.

• They revert back to reactants.

What are the products when calcium carbonate reacts with hydrochloric acid?

• Calcium oxide, water, and hydrogen gas.

• Calcium hydroxide, carbon dioxide, and chlorine gas.

• Calcium chloride, water, and carbon dioxide.

• Calcium carbonate, hydrochloric acid, and oxygen gas.

Why does the mass of reactants decrease during the reaction between calcium carbonate and hydrochloric acid?

• Carbon dioxide gas is produced and escapes.

• Water is consumed in the reaction.

• Calcium chloride precipitates out of solution.

• Hydrochloric acid evaporates.

Which experimental setup is suitable for measuring the decrease in mass of reactants over time?

• A gas syringe to collect gas.

• An electronic balance to measure mass changes.

• A calorimeter to measure heat changes.

• A pH meter to measure acidity.

When plotting the mass of reactants against time, what shape does the graph typically take for a chemical reaction?

• A downward curving line, indicating decreasing mass over time.

• An upward curving line, indicating increasing mass over time.

• A straight horizontal line, indicating constant mass.

• A straight diagonal line, indicating a constant rate of mass change.

How is the instantaneous rate of reaction determined from a graph of mass of reactants versus time?

• The area under the curve.

• The y-intercept of the curve.

• The gradient (slope) of the tangent to the curve at a specific point.

• The x-intercept of the curve.