Rate Of Reaction Flashcards
The rate of reaction depends on what four things?
1) temperature
2) catalyst
3) concentration
4) surface area of solids
What four things can be a cause of an increased rate?
1) increase in temperature
2) increase in concentration
3) catalyst added
4) solid reactant crushed up into smaller bits
What are three ways used to measure the rate of a reaction?
1) precipitation
2) change in mass
3) The volume of the gas given off
What is the equation for the rate of reaction?
Rate of reaction=
Amount of reactant used or amount of product formed
____________________________
Time
What is precipitation?
This is when the product of the reaction is it precipitative which clouds the solution
Through using precipitation how can you measure the quickness of the reaction?
1) observer mark to the solution and measure how long it takes for it to disappear the quicker the mark disappears the quicker the reaction
Why doesn’t precipitation work on all solutions to measure the rate of reaction?
Precipitation only works for reactions where the initial solution is rather see through
What is the problem with the results of precipitation?
The result is very subjective- different people might not agree over the exact point when the mark disappears
How can you Measure the rate of reaction using the change in mass?
Through measuring the gas given off
Why are measuring the speed of a reaction that produces a gas what can this be carried out on?
A mass balance
How does the mass balance work in measuring the speed of a reaction that produces gas?
As the gases are released the mass disappearing is easily measured on the balance. The quicker the reading on the balance drops the faster the reaction
I would of precipitation, change in mass and the volume of gas given off, which method is more accurate in measuring the rate of reaction?
Change in mass through using a mass balance
How is measuring the rate of reaction through the change in mass the most accurate method? Name a disadvantage
Because the mass balance is very accurate but he has the disadvantage of releasing the gas straight into the room
What is involved to measure the rate of reaction through the volume of gas given off?
This involves the use of a gas syringe to measure the volume of gas given off. The more gas given off during a given time interval the faster the reaction
Given advantage and disadvantage of using the volume of a gas given off as a method of measuring the rate of reaction
Advan- gas syringes usually give volumes accurate to the nearest millimetre, so they are quite accurate
Disad- if the reaction is to vigourous you can easily blow the plunger out of the end of the syringe
What is the big disadvantage of using the mass balance in terms of the flask?
If the flask is to hot you will lose mass by evaporation as well as in the reaction
What does the reaction of hydrochloric acid and marble chips demonstrate?
This experiment is is to demonstrate the effect of breaking the solid up into small bits
What is the reaction of magnesium metal with dilute HCI used to determine?
Used to determine the effect of concentration
What does the decomposition of hydrogen peroxide show?
This experiment looks and have a catalyst affects the rate of reaction
Give an example of a reaction that happens very slowly and one that is very fast
The corrosion of Arjen is a reaction that happens very slowly.
Explosions are very fast reactions
Give three ways of increasing the rate of reaction between magnesium and sulphuric acid
Increase the temperature of the acid
Use smaller pieces
Increase the acid concentration
Use a catalyst
Describe one way of monitoring a reaction in which gas is given off
Measure the volume of gas given off by collecting it in a gas syringe
Or monitor the mass of a reaction flask from which the gas escapes
How would reducing the concentration of an acid affect the time taken for a piece of zinc to react with it?
It would increase the time taken which would reduce the rate of reaction
Oxidation of lactose in milk makes it go sour. How could this reaction be slowed down?
By keeping the milk cool such as storing it in the fridge
