C5 Monitoring and Controlling Chemical Reactions Flashcards
What is atom economy
The atom economy is a measure of how many atoms in the products make up the desired product.
What is the formula used to calculate atom economy
π΄π‘ππ πππππππ¦= (Sum of ππ ππ πππ ππππ πππππ’ππ‘/Sum of ππ ππ πππ πππππ’ππ‘s) x 100
What factors should be considered when making a substance?
Yield of the product
Atom economy
Usefulness of bi-products
Rate of reaction
Equilibrium position if reversible
What is Theoretical Yield
The theoretical yield is the maximum possible mass of desired products you can make from a given mass of reactants.
What is percentage yield
The percentage yield is the amount produced compared to your theoretical yield
How do you calculate percentage yield ?
πππππππ‘πππ π¦ππππ= (πππ‘π’ππ yield) / (π‘βπππππ‘ππππ πππ π ) π₯ 100
The equation for concentration
πͺππππππππππππ= π¨πππππ/π½πππππ
Give units for concentration
g/dm3 or mol/dm3
What pieces of equipment are needed to carry out a titration
Burette, volumetric pipette, pipette filler, conical flask, white tile, clamp and stand, indicator.
What are concordant titre values
When the titre values are within 0.10 cm3
What is molar volume
1 mole of any substance in the gas state occupies the same volume at the same temperature and pressure
At room temperature and pressure (RTP) this volume is 24dm3 or 24000cm3
Write down the gas equations
ππππ’ππ‘ (πππ)= (π£πππ’ππ (ππ3))/24
π£πππ’ππ (ππ3 )=ππππ’ππ‘ (πππ) π₯ 24
What is rate of reaction
Measure of how quickly reactants are used or products are formed
Give formulae for measuring rate
π ππ‘π ππ πππππ‘πππ= (π΄πππ’ππ‘ ππ πππππ’ππ‘ πππππ’πππ)/ππππ
π ππ‘π ππ πππππ‘πππ= (π΄πππ’ππ‘ ππ πππππ‘πππ‘ π’π ππ)/ππππ
What has to happen in order for a reaction to happen between 2 particles
The reacting particles need to collide
The collision needs to have enough energy (more than the activation energy) so that the particles will then react (bonds will break etc)
Predict what will happen in terms of collisions if we increase the temperature of a reaction
The number of collisions increase because the particles are moving more quickly.
The percentage of collisions which are successful increases because all the particles have more energy
What is a catalyst?
A substance that increases the rate of the reaction but remains unchanged at the end.
They provide an alternative reaction pathway with a lower activation energy.
What is a reversible reaction
A reversible reaction is one in which the products are able to react with each other to change back into the reactants without any additional changes
Give an example of a reversible reaction
CuSO4.5H2O β CuSO4 + 5H2O
What is the equilibrium position
The position of equilibrium is related to the ratio of the concentration of products to the concentration of reactants
State if true or false for the following:
At equilibrium reactants are still reacting to make products.
At equilibrium you always have equal amounts of reactants and products.
Equilibrium always happens at the same point no matter the conditions.
When you decrease the concentration of the reactants the equilibrium point will be closer to the left.
Equilibrium can only be reached in a closed system.
At equilibrium reactants are still reacting to make products TRUE
At equilibrium you always have equal amounts of reactants and products FALSE
Equilibrium always happens at the same point no matter the conditions FALSE
When you decrease the concentration of the reactants the equilibrium point will be closer to the left TRUE
Equilibrium can only be reached in a closed system TRUE
What is Le Chatelierβs Principle?
Any change made to a reaction which is in equilibrium, will result in the equilibrium position moving to minimise the change made
What factors might change the position of equilibrium?
Temperature
Concentration
Pressure
What is dynamic equilibrium
The forward and backward reactions still happen and concentrations of all the reacting substances remain constant
