Unit 1 - Controlling the Rate Flashcards
What is the formula for Average Rate?
AR = change in property/change in time
What must you calculate for a Balanced Equation Calculation?
- Mole Ratio
- GFM
What methods can you use to monitor the reaction rate of a reaction?
- Measuring the mass of gas produced
- Measuring the volume of gas
- Measuring the pH of the acid/concentration of acid.
How do you measure the volume of an insoluble gas?
With a water trough
How do you measure the volume of a soluble gas?
With a syringe.
What is the formula for reaction rate?
RR = 1/Time
a. On a graph, what will the best fit line of concentration look like?
b.Why?
a. A straight line.
b. Rate and concentration are directly proportional to each other. (Double concentration = double rate)
a. On a graph, what will the best fit line of temperature look like?
b. Why?
a. A curved line.
b. Temperature and rate are not directly proportional to each other. (A small increase in temperature results in a large rate increase.)
How does increasing the temperature affect reaction rate?
Increasing the temperature increases the average kinetic energy of the particles, therefore more particles have energy greater than or equal to the activation energy. Therefore, more collisions and greater reaction rate.
What conditions must occur for successful collision results in a reaction?
- Correct collision geometry
- Energy greater than or equal to the activation energy.
What is temperature?
A measure of the average kinetic energy of the particles in a substance.
What are energy distribution diagrams used for?
To show the energies of particles in a substance at a particular temperature.
What do catalysts do to the rate of reactions?
Catalysts speed up reactions by providing an alternative reaction route with a lower activation energy. More particles can therefore have energy greater than or equal to the activation energy.
How can catalysts be helpful in making reactions more affordable?
Catalysts allow reactions to take place at a lower temperature, therefore saving money on energy costs.
How can catalysts be helpful in making reactions more affordable?
Catalysts allow reactions to take place at a lower temperature, therefore saving money on energy costs.
Which of the following is not a factor that affects the rate of a reaction?
A. Activation Energy
B. Kinetic energies of reactant molecules
C. Concentration of reactants
D. Enthalpy change of reaction
D
Which of the following is not a factor that affects the rate of a reaction?
A. Activation Energy
B. Kinetic energies of reactant molecules
C. Concentration of reactants
D. Enthalpy change of reaction
D
The relative rate of a reaction which reached completion in 1 minute 40 seconds is:
A. 0.010 s/1
B. 0.714 s/1
C. 0.010 min/1
D. 0.714 min/1
A
Time = 1 min 40 seconds = 100 seconds
RR= 1/time RR= 1/100 RR= 0.010s/1
What is Activation Energy?
The minimum kinetic energy required by colliding particles before a successful collision and subsequently reaction may occur.
What is enthalpy change?
Energy change that occurs when reactants are converted into products.
What is the enthalpy change in an exothermic reaction?
Negative (Energy in the form of heat is lost to the surroundings)
What is the enthalpy change in an endothermic reaction?
Positive (Energy in the form of heat is absorbed from the surroundings)
What is an activated complex?
An activated complex is an unstable arrangement of atoms formed at the top of the activation energy barrier. It’s an intermediate stage between reactants and products.
What is the name of the thing that forms at the top of a potential energy diagram?
Activated complex
How does particle size affect collision rate?
Decreasing particle size increases surface area. This results in more collisions and therefore more successful collisions.
Which does catalysts impact:
A. Activation Energy
B. Enthalpy of Reactants
C. Enthalpy of Products
D. Enthalpy Change
A. Activation Energy
What do catalysts do to the activation energy?
Lowers it.
How do you convert cm3 to liters?
➗ 1000
How do you convert g to kg?
Divide by 1000
How do you convert kg to g?
Multiply by 1000
How do you convert cm3 to g?
They’re the same.
How do you concert litres to kg?
They’re the same.
