Chemical Reaction Rates and Orders

The video reviews reaction rates for Year 13 chemistry, covering methods to measure rates, orders of reaction, and graphical analysis. It explains zero, first, and second order reactions, and how to use graphs to determine reaction rates. The concept of half-life is discussed in relation to reaction order. The video also covers formulating rate equations, calculating units, and introduces the rate determining step and reaction mechanisms.

What is the definition of the rate of a chemical reaction?

• The change in concentration of reactants or products per unit time

• The amount of product formed per unit time

• The total time taken for a reaction to complete

• The initial concentration of reactants

In a zero order reaction, how does the concentration of reactants affect the rate?

• The rate decreases with concentration

• The rate increases with concentration

• The rate fluctuates with concentration

• The rate is independent of concentration

For a first order reaction, if the concentration of a reactant doubles, what happens to the rate?

• The rate doubles

• The rate triples

• The rate remains the same

• The rate halves

What type of graph represents a zero order reaction in a concentration-time graph?

• A straight line with a positive slope

• A curve with increasing slope

• A straight line with a negative slope

• A curve with decreasing slope

How does the half-life of a first order reaction behave over time?

• It increases

• It decreases

• It remains constant

• It fluctuates

In a rate-concentration graph for a first order reaction, what is the shape of the graph?

• A flat line

• A straight line through the origin

• A parabolic curve

• A hyperbolic curve

What is the unit of the rate constant for a second order reaction?

• Moles per decimeter cubed per second

• Seconds to the minus one

• Moles to the minus one decimeter to the three seconds to the minus one

• Moles to the minus one decimeter cubed per second

What is the overall order of a reaction with the rate equation: rate = k[A]^0[B]^1[C]^2?

• Second order

• Fourth order

• First order

• Third order

How do you convert a proportionality into an equation in the context of reaction rates?

• By dividing by the time

• By multiplying by the concentration

• By subtracting the initial concentration

• By adding a constant of proportionality

What happens to the units of the rate constant as the order of the reaction increases?

• They become more complex

• They remain the same

• They become dimensionless

• They simplify