Chemistry HCL and Marble Chips
Chemistry HCL and Marble Chips
Aim
The aim of this experiment is to find out how different variables affect the rate at which the reaction between Marble chips (CaCO ) and Hydrochloric acid (HCl) takes place. There are many variables that effect the rate of this reaction such as the following:
. Temperature
2. Concentration (Pressure for gases)
3. Catalyst
4. Surface area
In my investigation I will be testing how changing the concentration of the Hydrochloric acid, the surface area of the marble chips and the temperature have an effect on the speed of the reaction. I will do various experiments and then evaluate the results and come to a conclusion.
The reaction that will take place is
Hydrochloric acid + Calcium Carbonate
Calcium Chloride + Water + Carbon dioxide
Introduction
Collision theory - Collisions between reactant particles are needed for the reaction to take place in order to form a product. Some collisions are successful and give a product while others don't because particles don't have enough energy.
Activation energy - The amount of energy needed for the reaction to be started. If there is enough energy then the reaction takes place and a product is formed, but if there isn't enough then no reaction takes place.
There are two possibilities for increasing the rate of reaction:
. The activation energy is reduced so that there is a better chance of particles having enough energy to react. Reactants will need less energy to react.
2. The number and strength of collisions is increased so that the reaction can
happen faster. If the particles have more energy then more particles will be able to react.
Solid reactants like marble chips are effected by surface area, the larger the surface area the more collisions that will take place. This will increase the rate of reaction and decrease the time taken.
Liquid/ Aqueous reactants rely on collisions for more collisions to take place. In a concentrated acid solution there are more acid particles so more collisions will take place. There will be an increase in the product formed in a certain time.
When the temperature is increased, the particles will have more energy, so they will move faster. This will result in the particles colliding more frequently and increasing the speed of the reaction. Also when they have more energy there will be more chance of the collisions being successful because the activation energy will be attainable.
The addition of a catalyst will reduce the activation energy and makes more successful collisions. The reaction will be faster but the catalyst will not be used up during the reaction. When the activation rate is lower not much energy is needed to make the reaction successful.
Concentration
Aim
The aim is to find out if changing the concentration of the hydrochloric acid solution has an effect on the time taken for the reaction
Prediction
The more concentrated the acid then the quicker the reaction will take place, because there will be more HCl particles than water particles for the marble chips to collide with and therefore react. More collisions between the two reactants (HCl and CaCO ) will take place resulting in a quicker time for the reaction.
I predict that if the concentration of the HCl is doubled ...
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Concentration
Aim
The aim is to find out if changing the concentration of the hydrochloric acid solution has an effect on the time taken for the reaction
Prediction
The more concentrated the acid then the quicker the reaction will take place, because there will be more HCl particles than water particles for the marble chips to collide with and therefore react. More collisions between the two reactants (HCl and CaCO ) will take place resulting in a quicker time for the reaction.
I predict that if the concentration of the HCl is doubled then the experiment will happen twice as fast. This is because twice as many HCl particles will be present than previously and there will be twice as much chance of the calcium carbonate chips colliding with the concentrated hydrochloric acid. Therefor when the concentration is double the time take for the reaction should be halved.
Variables
Independent - Concentration of the Hydrochloric acid solution
Dependent - The amount of CO produced
Control - Temperature, Surface area, Amount of HCl , Mass of marble chips
Apparatus
The solutions with different concentrations of acid have to be prepared before the reactions can start. The solution has to have a total volume of 10cm . The following solutions should be prepared by mixing water and the acid in a set ratio.
HCl H O
0 0
9 1
8 2
7 3
6 4
5 5
4 6
3 7
2 8
9
When the solutions have been prepared the apparatus has to be set up. The following equipment will be needed for the experiment.
Hydrochloric acid
Water
Calcium Carbonate chips
Conical flask
Glass capillary
Syringe
Rubber bung
Spatula
Clamp
Stand
Measuring cylinder
Stopwatch
Top pan balance
Method
When the apparatus has been set up as shown above, 10 cm of the acid solution will be measured using a measuring cylinder. This will be poured into a conical flask. 3g of powdered CaCO chips will be weighed out using a top pan balance. This will be put into the conical flask and the rubber bung attached to the syringe will be put over it immediately afterwards. At the same time the stopwatch will be started.
After every ten seconds the amount of CO released will be recorded by looking at the measurement on the syringe. This will be done for 100 seconds so by the end of the experiment 10 readings should be obtained.
The experiment will be repeated and carried out in the same way, only the concentration will be changed. A less or mare concentrated solution will be used but the total volume of the solution will stay the same.
Surface area
Aim
The aim of this investigation is to find out if the surface area of a calcium carbonate chip has an effect on the time taken for the experiment.
Prediction
The increase in surface area will result in a faster reaction. If the marble chips are powdered then the reaction will happen faster because more of the chip will be exposed to the acid and they will react quickly
When the surface area of the calcium carbonate chips is doubled there will be twice as much chance of it colliding with the Hydrochloric acid. Therefore I predict that when the surface area is doubled, the time taken for the experiment is halved.
Variables
Independent - Surface area of the marble chip
Dependent - the mass loss of the solution
Control - Temperature, Concentration, Amount of HCl , Mass of marble chips
Apparatus
Two experiments will be carried out, the first one will have marble chips with a large surface area and the second one will have marble chips will a small surface area. These will have to be prepared, the marble chip with the large surface area has to be crushed and the other one will be large blocks of the marble chip.
When the marble chips have been prepared the following apparatus has to be set up. The following equipment will be needed for the experiment.
Calcium Carbonate chips
Hydrochloric acid
Water
Top pan balance
Conical flask
Spatula
Measuring cylinder
Stopwatch
Method
When the apparatus has been set up as shown above, 25 cm of 2 M acid solution will be measured using a measuring cylinder. This will be poured into a conical flask. The Calcium Carbonate chips that have a large surface area will be taken and weighed out, 5 g will be taken. The all the contents will be weighed on the top pan balance and the solution will be left on the top pan balance even after the reaction has started. This is because the weight loss due to carbon dioxide being released has to be measured so that a conclusion can be made on the most affective surface area.
When the experiment has started the mass of the solution will be recorded every 30 seconds. This will be done for minutes so by the end of the experiment 20 readings should be obtained.
The experiment will be repeated and carried out in the same way, only this time the other marble chip will be used, the one that has a small surface area. All other variable will be controlled to make sure the experiment is fair.
Results
Time Weight (g) Weight loss (g)
(mins)
0.0 100.0 100.0 0.0 0.0
0.5 99.3 100.0 0.7 0.0
.0 99.0 99.8 1.0 0.2
.5 98.7 99.7 1.3 0.3
2.0 98.6 99.6 1.4 0.4
2.5 97.7 99.4 2.3 0.6
3.0 97.5 99.4 2.5 0.6
3.5 97.4 99.3 2.6 0.7
4.0 97.4 99.2 2.6 0.8
4.5 97.2 99.1 2.8 0.9
5.0 97.2 99.1 2.8 0.9
5.5 97.2 99.0 2.8 1.0
6.0 97.1 99.0 2.9 1.0
6.5 97.1 99.0 2.9 1.0
7.0 97.0 99.0 3.0 1.0
7.5 96.9 98.9 3.1 1.1
8.0 96.9 98.8 3.1 1.2
8.5 96.9 98.8 3.1 1.2
9.0 96.8 98.7 3.2 1.3
9.5 96.8 98.7 3.2 1.3
0.0 96.8 98.7 3.2 1.3
I found that the marble chips of large surface area reacted straight away, but as time went on the reaction slowed down. But with marble chips of small surface area the reaction process stayed constant throughout the experiment.
After the powder marble chips were poured into the conical flask the reaction started straight away but slowed down after just 1second. The fastest rate of the reaction was in the first second.
The experiment was a success. When I done this experiment I found that surface area is a factor that affects the rate of reaction. As I increased the surface area of the calcium carbonate (i.e. made the pieces smaller), the rate of the reaction was increased (the reaction was faster).
Temperature
Aim
The aim of this experiment is to observe whether the temperature of the solution has an effect on the time taken for the experiment.
Prediction
If the temperature at which the reaction takes place is increased then the reaction will be faster because the particles will have more energy and therefore collide more often.
A temperature increase of 10 C will see the time taken for the experiment halved because energy of collisions in the particles increases, this means that there are going to be more successful collisions.
Variables
Independent - temperature of the solution
Dependent - amount of carbon dioxide gas collected
Control - Surface area, Concentration, Amount of HCl , Mass of marble chips
Apparatus
Sodium thiosulphate
Hydrochloric acid
Top pan balance
Conical flask
Spatula
Measuring cylinder
Stopwatch
Bunsen burner
Thermometer
Tripod
Paper
Marker (dark coloured)
Light (match, spark)""
Method
For this experiment I will be using I will set up the apparatus as shown above. I will then get the sheet of paper and using the marker, I will draw a large cross on it. Measure out 50cm3 of sodium thiosulphate using the measuring cylinder. Once this is done pour it into the conical flask. Place the conical flask on the tripod and using the Bunsen burner heat the conical flask containing the sodium thiosulphate, put a thermometer inside and wait until the reading on the thermometer is at the required level.
I will then place the conical flask on the piece of paper with the cross. Now measure 5cm3 of the hydrochloric acid and pour it into the test tube. Pour the acid into the conical flask and start timing straight away. Wait until the cross cannot be seen any more and stop the timer. Repeat this for all the measurements 10, 20, 30, 40, 50 and 60 degrees Celsius. The experiment will be done three times and the average will be taken from all the results.
Results
Temp CO gas
( C) set 1 set 2 set 3 average
0 12 10 14 12.0
20 23 25 18 22.0
30 40 38 41 39.7
40 70 72 69 70.3
50 120 115 128 121.0
60 200 204 203 202.3
As the temperature got higher the rate of the reaction speeded up. The cross disappeared faster. Those of higher temperature had more carbon dioxide produced thus causing the cross to disappear.
This experiment was successful. It proved my prediction correct. As the temperature was increased so did the rate of reaction. It proved that the temperature is a factor that affects the rate of reaction.
Results
These were the results obtained after doing the experiment with different concentrations of the Hydrochloric acid.
0 20 30 40 50 60 70 80 90 100
0:00 65 82 84 100 108 110 110 110 110 110
09:01 53 72 80 84 92 103 109 110 110 110
08:02 46 61 64 71 77 81 85 92 101 110
07:03 37 48 59 65 68 70 72 73 75 78
06:04 20 30 35 41 45 50 52 56 60 61
05:05 17 25 32 36 42 45 49 52 55 57
04:06 11 15 21 26 31 35 40 45 48 51
03:07 9 13 19 22 25 27 31 34 35 36
02:08 5 11 15 19 23 25 27 29 31 31
01:09 3 7 13 15 16 17 19 22 23 25
I found that as I increased the concentration of the acid, there was more reaction and a faster reaction. Hence more hydrogen gas produced. By looking at graph, line for the least concentrated solution was the least steep and this meant it was also the slowest.
The experiment was a success. When I done this experiment I found that concentration is a factor that affects the rate of reaction. As I increased the surface area of the calcium carbonate (i.e. made the pieces smaller), the rate of the reaction was increased (the reaction was faster
