...ecies must:
Be able to collide with a minimum energy to overcome activation energy
Collide the right way round otherwise the molecules will bounce of each other
Factors that affect the Rate of Reaction
There are three ways out of which will effect the reaction rate.
Temperature- Increasing the temperature, increases the amount of energy the molecules have. As there is more energy, the impact energy will be larger, allowing activation energy to be overpowered.
Surface area- If you break up the reactant, you are increasing, the surface area, exposing more molecules,
Concentration- When you increase the concentration you, increase the amount of atoms in each cm3 of volume. Increasing the number collisions that take place.
Each of these factors affect collision theory.
Variables
The variable will be the concentration of the sulphuric acid. I can change by using the different concentrations of acid available. Constant Variables: I will be keeping the volume of acid the same (20cm3) and the same amount of magnesium ribbon (10cm)
The experiment will be conducted at room temperature although the temperature may change due to the changing of rooms, and we do not have a thermostat to adjust.
The method will also be kept the same
Hypothesis
By increasing the concentration of sulphuric acid, I am increasing the number of atoms in the volume of liquid. This means there is then a larger chance of the particles reacting. My prediction is the reaction rate will speed up as I increase the concentration. Therefore, if I quadruple the concentration, the reaction rate will be four times as fast. This is proved above In “Factors that affect the Rate of Reaction”
Equipment
To conduct this experiment I will need
A stopwatch
Conical flask (with an arm to connect to the gas syringe)
Gas syringe
A wooden block to hold up the flask
Ignition tube
Measuring tube
Ruler
I will be using a stopwatch because it is digital, you can pinpoint the timing. It is much more accurate than an analogue watch. You can also stop and start it, or reset it if there is a mistake in the experiment.
I am using a conical flask with an arm, as it is the most practical thing I could think of using, that would suit the criteria. Also because there is an arm I don’t need to attach a tube, which could leak gas.
I am using a gas syringe because it is more accurate than using a measuring cylinder upside down, also it is less likely hydrogen will be leaked.
I am using a wooden block to hold the gas syringe because it is sturdy, and is the only thing available.
I chose to use an ignition tube because it is small enough to fit in the conical.
Diagram
Method
The experiment will be conducted at room temperature.
Measure the amount of sulphuric acid (20cm3 ) and magnesium (10cm).
Connect the conical flask to the gas syringe (where they connect there will be a piece of rubber to ensure that no hydrogen is leaked).
Place the gas syringe on a wooden block. Once this is setup I will pour in the sulphuric acid into the conical first
Then put the magnesium ribbons in the ignition tube and bung it. During the experiment my partner or myself will have a stopwatch and will call out every 10 seconds and the other person will record the amount of gas produced, we will repeat this for 1-2 minutes.
I will repeat the experiment again with the same concentration, and then work out an average, this will make my results reliable and accurate.
Then I will do the exact same process again but with a different concentration of acid.
How & What I’ll be Measuring
Since I cannot measure the amount of salt being produced as it would be too difficult to separate the salt from the solution and would not be realistic. Instead I will measure the amount of hydrogen produced using a gas syringe, this data will be put on my Y-axis on a graph, which will help me determine the rate of reaction. The time will be measured so I can put it on my X-axis on a graph, to help me measure the rate of reaction.
Making it a Fair Test
To make sure that it is a fair test I will make ensure that the same amount of sulphuric acid and magnesium are used in each instance. I will also make sure that I do not use too much sulphuric acid or magnesium, so that the gas produced does not go off the scale.
Test Experiment with Magnesium Powder
In this experiment we decided to use 0.5g of magnesium powder and 20cm3 of 1m sulphuric acid.
Time 30 60 90 120
Cm3 Hydrogen produced 55 77 Off the scale -
The reactants reacted too quick, and went of the scale. This is because the powder has a larger surface area.
Quantity Justification
20cm3 of acid
10cm of magnesium ribbon
I am using these quantities because when I am recording the results I do not want the amount of product produced to go off the scale. So that the graph is more accurate as there would be more data.
Pilot Tes...