4.6.1 Rate of reaction Flashcards
(13 cards)
How is the rate of a chemical reaction calculated?
The rate of a chemical reaction can be found by measuring the quantity of a reactant used or the quantity of product formed over time.
What is the formula for the mean rate of reaction using reactants?
Mean rate of reaction = quantity of reactant used / time taken
What is the formula for the mean rate of reaction using products?
Mean rate of reaction = quantity of product formed / time taken
How can the quantity of reactant or product be measured?
The quantity can be measured by mass in grams or by volume in cm³.
What are the units for rate of reaction?
The units may be given as g/s or cm³/s.
What additional requirements are there for Higher Tier students regarding rate of reaction?
Higher Tier students must use quantity of reactants in moles and units for rate of reaction in mol/s.
What skills should students be able to demonstrate regarding rates of reaction?
Students should be able to calculate the mean rate of a reaction, draw and interpret graphs, and calculate the gradient of a tangent to the curve.
What factors affect the rates of chemical reactions?
Factors include concentrations of reactants, pressure of gases, surface area of solids, temperature, and presence of catalysts.
What is required practical 5 about?
It investigates how changes in concentration affect the rates of reactions by measuring gas volume or changes in color/turbidity.
What does collision theory explain?
Collision theory explains that reactions occur when particles collide with sufficient energy, known as activation energy.
How do changes in concentration, pressure, and temperature affect reaction rates?
Increasing these factors increases the frequency of collisions and the rate of reaction.
What role do catalysts play in chemical reactions?
Catalysts change the rate of reactions without being used up and provide a pathway with lower activation energy.
What is a reaction profile for a catalyzed reaction?
It shows the energy changes during a reaction, indicating the lower activation energy provided by the catalyst.
