Calculating and Measuring Chemical Reaction Rates

The video tutorial explains how to calculate the mean rate of a chemical reaction using different methods. It provides examples involving magnesium and hydrochloric acid, and calcium carbonate with hydrochloric acid. The tutorial demonstrates how to measure reaction rates by tracking product formation, reactant usage, and mass change over time. It also discusses how the rate of reaction decreases as the reaction progresses.

What is the mean rate of a chemical reaction defined as?

• The temperature change during the reaction

• The time taken for a reaction to start

• The quantity of reactant used divided by the time taken

• The color change observed in the reaction

In the first example, how is the mean rate of reaction calculated?

• By calculating the pressure change

• By observing the color change

• By measuring the amount of hydrogen gas produced

• By measuring the temperature change

What is the mean rate of reaction when a magnesium ribbon disappears in 40 seconds?

• 0.5 per second

• 0.37 per second

• 1.0 per second

• 0.025 per second

What happens to the total mass of the flask and its contents during the reaction between calcium carbonate and hydrochloric acid?

• It fluctuates randomly

• It increases over time

• It remains constant

• It decreases over time

What does a decreasing gradient on the graph indicate about the rate of reaction?

• The rate of reaction is unpredictable

• The rate of reaction is decreasing

• The rate of reaction is increasing

• The rate of reaction is constant