If we double the concentration, there will have half space, the particles will have double chance to meet each other, hit each other and react with each other. So this is the reason for my predation.
There is a diagram shows the idea of concentration:
Apparatus needed
The reason for I chose the gas collection method is I think when the mass and concentration is very low then you will get less gas produce. Use gas syringe is not good for measuring these small numbers; the result is not very accurate. So I decided to use the gas collection tube in my experiment. But the disadvantage is when I doing the experiment there will be some carbon dioxide dissolve slightly in water.
Diagram of apparatus
There is another diagram below:
As you can see the first diagram shows the method that how can you let these calcium carbonate (marble) react with hydrochloric acid (HCl). It shows very clearly that which instrument you need for this experiment. But it has not got any measuring stuff, so you cannot find out the result very accurate.
The second diagram shows the idea that I will use in my experiment. All the instruments will exactly the same that I will use in my experiment. The different is I will measure the mass of marble before I do the experiment and I will use measuring cylinder to measure the volume of acid solution.
Preliminary work
I have done an experiment on a computer program. It is called calcium carbonate – HCl reaction. All the instruments I need for that experiment are showing below:
The result of this experiment is showing below:
- In this experiment I used the mass of calcium carbonate is 5.00 grams and volume of HCl is 50 cm³.
There is another table to shows the result I’ve got from an experiment:
From the table above shows the result, I decided I am going to use the concentration between the 0.10M to 1.00M, and I will chose five different concentrations they are:
- 0.30M
- 0.50M
- 0.60M
- 0.80M
- 1.00M
The reason for this is I think when the concentration was 0.30 the result was very low; the speed is too slow to measure. I do not think I will get more accurate result, so I use 0.30M as the lowest concentration. Others we knew the highest concentration is 1.00M so I include this concentration, 0.50M is the middle number so I want to know what is the result when the concentration is half. 0.60M and 0.80M is two gaps between the 0.50M and 0.80M. So I want to know what are the results of these two concentrations.
Safety
When I doing the experiment I will follow the science lab rules properly all the time. I will wear the safety gasses, make sure any hydrochloric acid solution will not spill out and will not get anywhere on my body because it can corrupt your skin and other equipments in the science lab. I will not smell the gas when it is come out. If these things will happen I will ask my science teacher for help.
Fair test
In this experiment I will keep these factor same all the time when I doing the experiment:
- Temperature
- Surface area
- Catalyst
- The mass of calcium carbonate.
I will change the concentration of the acid that is because this is the course I need to investigate.
The mass of calcium carbonate I will keep it 0.50 grams. Temperature I will keep it 40°C. surface area will be medium.
Accuracy
In my experiment, I will use stopclock to measure the time, the accurate result can be 0.01 second and I will use a gas collection tube to measure the volume of gas collected. The accurate result can be 1/10 cm³. I will use a top pan balance to mass of marble to 0.01g. I will use 50 cm³ measuring cylinder to measure the volume of water and acid. When I use measuring cylinder I will put it on the table and bend down to put my eye to top of liquid and read the bottom of the curve of the liquid.
If there is time I will repeat the experiment with each concentration three times and find the average.
Range of five concentrations
In my preliminary work I already wrote which concentration I will use in my experiment, they are:
- 0.30M
- 0.50M
- 0.60M
- 0.80M
- 1.00M
The reason for this is:
I think when the concentration was 0.30 the result was very low; the speed is too slow to measure. I do not think I will get more accurate result, so I use 0.30M as the lowest concentration. Others we knew the highest concentration is 1.00M so I include this concentration, 0.50M is the middle number so I want to know what is the result when the concentration is half. 0.60M and 0.80M is two gaps between the 0.50M and 0.80M. So I want to know what are the results of these two concentrations.
Checking reliability
To make my result to be reliable I will compare my result to other group students to see if we got similar result. I will ask teacher to check my result if it is fine, and I will ask my teacher to give me some suggestion that I can make my result more reliable. Also I can use the computer program to check my result and use my result to compare the result they have got. If I did anything wrong with my experiment I will do it again. I will know if result is wrong because it will not follow the same pattern as the rest.
Step by step detail
The list below shows all the instruments I will use in my experiment.
- One top pan balance
- One gas collection tube
- One stopclock
- One stopper
- One bowl
- Two pieces of clamp
- One conical flask
- 0.5 gram of medium size marble
- 50 ml of hydrochloric acid solution
The method:
- Prepare all the instruments ready. Example: collect combine all tubes together one side link to the gas collection tube another side link to the conical flask. Fill in the water into bowl and gas collection tube. Test the stopclock.
- Weight out 0.5g medium size marble chips on a balance.
- Measure out 50ml of hydrochloric acid using a measuring cylinder.
- Place marble chips into the conical flask.
- Put the acid solution into the flask and put the stopper into the flask.
- When first bubble appears, start the stopclock.
- Every 30 seconds take the volume of gas reading from the gas collection tube.
- I will stop measuring when the gases fill whole space of gas collection tube.
