Factors Affecting Reaction Rates

The video tutorial explains the use of graphs in A-level chemistry, focusing on concentration versus time and volume versus time graphs related to the rate of reaction. It covers the reaction of magnesium with sulfuric acid, how to calculate the rate of reaction using the gradient of a curve, and the effects of changing reaction conditions. Observations in a lab setting and the impact of doubling the acid volume are also discussed. The video concludes with recommendations for further study on the OCR specification.

What type of graphs are commonly used in A-level chemistry to study reaction rates?

• Pressure versus time

• Concentration versus time

• Temperature versus time

• Mass versus time

In the reaction between magnesium and sulfuric acid, what is the limiting reagent?

• Magnesium

• Water

• Hydrogen gas

• Sulfuric acid

How is the rate of reaction determined from a graph?

• By finding the midpoint of the curve

• By counting the number of peaks

• By calculating the gradient of a tangent to the curve

• By measuring the area under the curve

Why is it important to use a large triangle when calculating the gradient of a tangent?

• To make the graph look better

• To ensure accuracy in the gradient calculation

• To simplify the calculation

• To avoid errors in the x-axis

What effect does increasing the temperature have on the rate of reaction?

• Decreases the rate

• Has no effect

• Increases the rate

• Stops the reaction

What happens to the graph when the surface area of a solid reactant is increased?

• The graph shifts downwards

• The graph flattens out

• The gradient becomes steeper

• The graph becomes a straight line

What observation would you expect in a lab if the reaction rate increases?

• Less bubbling

• No change in appearance

• More vigorous bubbling

• The solution turns blue

What does the plateau on a reaction graph indicate?

• The reaction has finished

• The reaction is ongoing

• The reaction is starting

• The reaction is slowing down

If the volume of sulfuric acid is doubled, what happens to the volume of hydrogen gas produced?

• It remains the same

• It is halved

• It is doubled

• It decreases

What happens to the frequency of collisions as the concentration of acid decreases?

• Collisions become less frequent

• Collisions remain the same

• Collisions become more frequent

• Collisions stop completely