Rate of Reaction Flashcards
What is the rate of a chemical reaction?
The speed at which reactants are used up or products are formed.
What are two equations for calculating rate of reaction?
Rate = amount of reactant used / time
Rate = amount of product formed / time
What are the common units for rate of reaction?
g/s, cm³/s, mol/s
How can the amount of reactant or product be measured?
Mass (g) or volume (cm³)
How do you find the rate of reaction from a graph?
Draw a tangent and calculate its gradient.
What five factors affect the rate of a chemical reaction?
Concentration, pressure, surface area, temperature, catalysts.
How does increasing concentration affect the rate of reaction?
More particles per unit volume → more frequent collisions → faster reaction.
How does increasing pressure affect gas reactions?
Particles are closer together → more frequent collisions → faster reaction.
How does increasing surface area affect the rate of reaction?
More exposed particles → more frequent collisions → faster reaction.
How does increasing temperature affect the rate of reaction?
Particles move faster → more frequent and energetic collisions → faster reaction.
What is the effect of a catalyst on the rate of reaction?
Lowers activation energy → increases proportion of successful collisions.
What is collision theory?
A reaction occurs when particles collide with enough energy to react.
What is activation energy?
The minimum energy required for a reaction to occur.
How does increasing temperature affect activation energy?
It doesn’t change activation energy, but more particles have enough energy to react.
Why does increasing surface area increase the frequency of collisions?
More particles are exposed, allowing more frequent collisions.
What is a catalyst?
A substance that speeds up a reaction without being used up.
How does a catalyst speed up a reaction?
It lowers activation energy by providing an alternative reaction pathway.
Why are catalysts important in industry?
They reduce costs by lowering energy requirements and speeding up reactions.
What is a biological catalyst called?
An enzyme
What is a reversible reaction?
A reaction where products can reform reactants under certain conditions.
What symbol represents a reversible reaction?
⇌
How do reversible reactions relate to energy changes?
If a reaction is exothermic in one direction, it is endothermic in the other.
What is equilibrium in a reversible reaction?
The point where both forward and reverse reactions occur at the same rate.
