C.5 - Chemical Reactions Flashcards
Rate of reaction, Collision theory, Catalysts, Dynamic equlibrium, Le chateliers principle
What is dynamic equilibrium?
When the rate of forward reaction, is equal to rate of backwards reaction
Which reaction is happening at equilibrium?
Both
What is a closed system?
A sealed container, and none of the reactants can escape
Can equilibrium happen at different rates?
Yes
Do both reactions happen at the same speed?
No, as the reactants turn into products. The forward rate of reaction slows down and the backwards rate of reaction speeds up
At equilibrium are both reactions still happening?
Both reactions are still happening but they cancel eachother out
Will the concentration of reactants and products change when in equilibrium?
No they stay the same but they arn’t the same amount
What is Le Chateliers Principle?
Change the conditions of a reversible reaction the position of equilibrium will shift to counter act the change
Decreasing the temperature of an exothermic reaction does what?
Equilibrium moves in the exothermic direction
Increasing the temperature of an endothermic reaction does what?
Equilibrium moves in the endothermic direction
Increasing the pressure does what to equilibrium?
Equilibrium position moves to the least number of molecules
Decreasing the pressure, does what to equilibrium?
Equilibrium moves to the most number of molecules
What does concentration do to the equilibrium?
Whichever side increases concentration, equilibrium shifts to other side to counter act
What is the definition of a chemical reaction?
A process where reactants transform into products through the breaking and forming of bonds.
What is the definition of the rate of a reaction
The speed at which reactants are converted into products.
What are the factors that affect the rate of reaction?
Temperature, concentration, surface area, and catalysts
What effect does increasing temperature have on the rate of a chemical reaction?
It increases the rate of reaction.
What does surface area do to the rate of reaction
Increases rate of reaction
What is a catalyst?
A substance that increases the rate of a reaction without being consumed in the process.
True or False: Catalysts change the position of equilibrium in a reversible reaction.
False
Fill in the blank: A higher concentration of reactants generally leads to a _____ rate of reaction.
faster
What is the role of surface area in reactions?
Increasing surface area allows more particles to collide, increasing the rate of reaction.
What happens to the rate of reaction as reactants are consumed?
The rate of reaction decreases.
True or False: Increasing the pressure only affects reactions involving gases.
True
What is an electromagnetic wave?
transverse waves. Their vibrations or oscillations are changes in electrical and magnetic fields
What is dynamic equilibrium?
A state in a reversible reaction where the rates of the forward and reverse reactions are equal.
Multiple Choice: What happens to the equilibrium position if the concentration of reactants is increased? A) Shifts to the left B) Shifts to the right C) No change D) None of the above
B) Shifts to the right
What does Le Chatelier’s Principle state?
If a system at equilibrium is subjected to a change, the system will adjust to counteract that change.
True or False: A decrease in temperature favors the exothermic direction of a reversible reaction.
True
Fill in the blank: The _____ of a reaction is influenced by the nature of the reactants.
rate
What is meant by the term ‘activation energy’?
The minimum energy required for a reaction to occur.
Multiple Choice: Which of the following can lower the activation energy of a reaction? A) Heat B) Catalysts C) Increased concentration D) All of the above
B) Catalysts
What is the effect of a catalyst on the activation energy?
It lowers the activation energy required for the reaction.
True or False: The presence of a catalyst affects the energy of the reactants and products.
False
What is the relationship between reaction rate and collision frequency?
Higher collision frequency typically increases the reaction rate.
Fill in the blank: In a chemical reaction, the _____ must collide with sufficient energy to react.
reactants
What can be concluded about the effect of concentration on the rate of reaction?
Higher concentration increases the number of collisions, thus increasing the rate.
Explain, in the collision theory. How temperature affects rate of reaction?
There is an increase in energy - activation energy is reached quicker, particles move faster. and that will increase the reaction rate.
Explain, in the collision theory. How concentration affects rate of reaction?
The chances for collisions between molecules are increased because there are more molecules so things are reacting more frequently. Increasing rate of reaction
Explain, in the collision theory. How pressure affects rate of reaction?
The particles in the gas state become more crowded meaning they react more frequenly
Explain, in the collision theory. How catalysts affects rate of reaction?
Lower activation energy so collisions happen quicker
