Investigation Into the Rates of Reaction.
INVESTIGATION INTO THE RATES OF REACTION.
INVESTIGATION INTO THE RATES OF REACTION.
PLAN
INTRODUCTION: To investigate the rate of reaction I have decided to use the concentration as a variable, I am going to use marble chips (calcium carbonate) and hydrochloric acid. I will alter the concentration of the hydrochloric acid each time, and I will measure the amount of carbon dioxide product given off.
AIM: To find the rate of the reaction of hydrochloric acid reacting with marble chips.
EQUIPMENT LIST: DIAGRAM:
. Delivery tube
. Inverted measuring cylinder
. Trough
. Bung
. Conical flask
. Stop clock
. Measuring cylinder
EQUATION:
Calcium carbonate + Hydrochloric acid --> Calcium chloride + water + Carbon dioxide
CaCO3+ 2HCL --> CaCL2 + H2O + CO2
How we will use the apparatus safely
It is important we use the apparatus carefully and safely, ensuring there are no accidents. As we are using a concentrated acid, we must wear goggles and be extra careful. If any of the acid spills onto our hands, it should be washed off immediately and reported to the teacher. We should also wear an apron, ensuring the acid does not come into contact with our skin or clothes.
What are we measuring?
We will be measuring the amount of CO2 given off from the hydrochloric acid. The inverted measuring cylinder will measure this in (cm³).
To keep this test fair;
To keep this test fair we will keep the mass of the marble chip (calcium carbonate) the same (1.23g). We will also be keeping the temperature the same (room temp). The total volume of hydrochloric acid will also be kept the same (50 cm³).
In order to ensure this test is kept even fairer, we will use the same equipment. Some delivery tubes vary in length, so we shall keep that the same. We also need to make sure the bung is placed in immediately on, when the reaction begins.
The only thing we will be changing is the molarity of the acid. Human error is negligible, some CO2 may escape.
We will change the concentration of the hydrochloric acid.
We will do this, by adding water. For example, the total volume will be kept the same (50cm³), but it is the concentration of the acid that we will be changing. At one time the volume of acid could be 30cm³ and the volume of water could be 20cm³. Still resulting in a total volume of 50cm³. We will be using certain apparatus
to measure things accurately. This includes an inverted measuring cylinder. This device will measure the amount of CO² released in (cm³).
There are 5 main factors that affect the rate of reaction.
These are;
. Surface area of the reactants
. Concentration of the reactants
. Temperature at which the reaction is carried out
. Light
. Use of catalyst
The factor that we will be investigating is the concentration of the reactant, (in this case, hydrochloric acid)
To keep this test fair, we will need to keep some factors the same. This includes,
. The mass of the chip (1.23g)
. The temperature of the room (room temp)
. Total volume of acid the same (50 cm³)
The one factor that we will change is the concentration of the hydrochloric acid, by adding water to it.
In order for this to be an accurate and fair test, we need to take several readings for all measurements to allow us to average the results. We will try to do this, but as we have such unlimited time we may only get to take 3 readings. The more readings taken, the easier it is for us to draw a conclusion.
The measurements will range from 0-210 secs. We will be measuring the amount of CO²realeased in (cm³), using an inverted measuring cylinder.
PREDICTION
The products of the reaction are formed as a result of the collisions between reactant particles. There are more particles in a more concentrated solution and collisions occur more often. I predict the more often. I predict the more often they collide, the more chance they have of reacting. This means that the rate of a chemical reaction will increase if the concentration of reactants is increased.
In reactions involving only gases, an increase in the overall pressure at which the reaction is carried out increase the rate of reaction. The increase in pressure results in the ...
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The products of the reaction are formed as a result of the collisions between reactant particles. There are more particles in a more concentrated solution and collisions occur more often. I predict the more often. I predict the more often they collide, the more chance they have of reacting. This means that the rate of a chemical reaction will increase if the concentration of reactants is increased.
In reactions involving only gases, an increase in the overall pressure at which the reaction is carried out increase the rate of reaction. The increase in pressure results in the gas particles being pushed closer together. This means that they collide more often and so react faster.
A chemical reaction is a process by which one or more substances called reactants changes into one or more other substances, called products.
A reaction is when two particles (reactants) join to form a new product or products. Rate is a measurement of the change that happens in a single unit of time, any suitable measurement can be used such as seconds, minutes, hours or even days. A rate of a chemical reaction is how fast the reactants react. In general, to find the rate of reaction, you should measure either the amount of reactant used up per unit of time.
Rate of reaction (cm³/sec)=volume of gas (cm³)
Time taken (sec)
The rate during the reaction does not stay constant, it changes throughout the reaction, its greatest at the start but gets slower as the reaction proceeds. I think this is mainly to do with the fact the longer the reaction, has taken place, the more of the reactants react leaving fewer reactants with less chance of reacting.
For the reactants to be able to react they have to successfully collide with each other. The chance of a successful collision can be increased can increased or decreased by using many different factors. The factor we are investigating, in this experiment is the concentration of the reactant (hydrochloric acid).
In this experiment, we will be testing different concentrations, to change the concentration we will add water, ensuring the total volume is the same ( 50cm³).
HOW DOES THE CONCENTARTION AFFECT THE RATE OF REACTION?.
Concentration effects the rate of reaction because the higher the concentration of a particle, the greater the chance of a successful collisions. I predict, the general trend for the concentration is the rate doubles as the concentration doubles (they're directly proportionate).
Activation energy is the amount of energy required for the reactants to successfully react. The reactants need a certain amount of energy, any extra energy increases they're chance of a successful collision.
I predict the higher the concentration of particles, the greater the chance of a successful collision. I predict as the concentration doubles, the rate also doubles. I predict the higher the concentration, the faster the rate of reaction.
I predict that the marble and hydrochloric acid reaction will show us that, when a solid reacts with a solution, the reaction goes faster if the solution (hydrochloric acid), is more concentrated. This is because the marble is a solid. Its particles are vibrating slightly, but cannot move around freely. The hydrochloric acid is made up of several different sorts of particles. It contains water molecules, H+ions and Cl-ions. These are all in constant motion. They are moving around freely.
For the reaction to occur, we predict the H+ions must collide with the marble particles. The harder they hit, the more likely it is that the particles will react together. Anything that makes the acid and marble particles collide more often, or collide more violently, will speed up the reaction.
A more concentrated acid has more acid particles per cubic centimetre. So the acid particles will collide with the marble more often.
In a lump of marble (calcium carbonate), only the particles on the surface can come into contact with the acid. So only they can react. If you break the marble apart, more of it can react (although it isn't the surface area that we are measuring, it is the concentration).
In general, I predict reactions go faster when the concentration of reactants is increased. Therefore, I predict the reactant with the highest concentration (50cm³acid, 0cm³water will react the fastest.
I predict, a chemical reaction cannot happen unless particles in the reacting substances collide with each other
Reaction rate=change in mass (concentration) of a substances
Time taken
Hydrochloric acid reacts with marble chips (calcium carbonate). One product is C02 gas. We will measure the rate of reaction by timing how long it takes to make certain amount of gas. We are going to alter one factor, to find out whether it affects the rate of reaction. This factor is the concentration of the hydrochloric acid.
We will carry out this experiment as accurate and reliable as we possibly can. Therefore our measurements will have to be precise. We will carry out preliminary tests to find out how many parts of water will be used against acid.
We must remember, the higher the concentration of acid, the more successful collisions between acid and calcium carbonate. Also another variable, the temperature will increase because there are more collisions, which means more heat is produced. We will get a higher rate than expected.
PRELIMINARY RESULTS
VOLUME OF ACID
(Cm³)
VOLUME OF WATER
(Cm³)
TOTAL VOLUME
(Cm³)
50
40
30
20
0
0
0
0
20
30
40
50
50
50
50
50
50
50
From looking at the above table, you can see we are keeping the total volume the same 50(Cm³). In our preliminary testing, we worked out what concentrations to use. I.e., the amount of water to the amount of acid. We will work out the molars at the end using this equation;
Vol of acid (cm³)
Total volume of acid + water (cm³) x 2M=final molarity
CONCENTRATION = 50(Cm³) acid & 0(Cm³) water
TIME (secs)
VOLUME OF GAS (Cm³)
TEST 1
TEST 2
TEST 3
TEST 4
AVERAGE
0
30
60
90
20
50
210
240
270
300
0
8
6
25
34
44
53
0
8.5
6.5
26
33
42
51
0
7
4
24
35
43
52
0
8
5
24
34
42
52
0
8
5
25
34
43
52
CONCENTRATION = 30(Cm³) acid & 20(Cm³) water
CONCENTRATION 20(Cm³) acid & 30(Cm³) water
CONCENTRATION = 10(Cm³) acid & 40(Cm³) water
TIME (secs)
VOLUME OF GAS (Cm³)
TEST 1
TEST 2
TEST 3
TEST 4
AVERAGE
0
30
60
90
20
50
210
240
270
300
CONCENTRATION = 0(Cm³) acid & 50(Cm³) water
TIME (secs)
VOLUME OF GAS (Cm³)
TEST 1
TEST 2
TEST 3
TEST 4
AVERAGE
0
30
60
90
20
50
210
240
270
300
CONCLUSION
Our prediction proved to be correct. The products of the reaction were formed as a result of the collisions between reactant particles. There were more particles in a more concentrated solution and collisions occured more often. The more often they collided, the more of a chance they had of reacting. This meant that the rate of a chemical reaction increased when the concentration of the reactant was increased.
In reactions involving only gases, an increase in the overall pressure at which the reaction is carried out increases the rate of reaction. The increase in pressure resulted in the gas particles being pushed closer together. This meant that they collided more often and so they reacted faster.
A chemical reaction is a process by which one or more substances called reactants changes into one or more other substances, called products.
A reaction is when two particles (reactants) join to form a new product or products. Rate is a measurement of the change that happens in a single unit of time, any suitable measurement can be used such as seconds, minutes, hours or even days. A rate of a chemical reaction is how fast the reactants react. In general, to find the rate of reaction, you should measure either the amount of reactant used up per unit of time.
The rate during the reaction does not stay constant, it changes throughout the reaction, its greatest at the start but gets slower as the reaction proceeds. I think this is mainly to do with the fact the longer the reaction, has taken place, the more of the reactants react leaving fewer reactants with less chance of reacting.
For the reactants to be able to react they have to successfully collide with each other. The chance of a successful collision can be increased can increased or decreased by using many different factors. The factor we are investigating, in this experiment is the concentration of the reactant (hydrochloric acid).
In this experiment, we tested different concentrations; to change the concentration we added water, ensuring the total volume was the same (50cm³).
HOW DID THE CONCENTARTION AFFECT THE RATE OF REACTION?
Concentration effects the rate of reaction because the higher the concentration of a particle, the greater the chance of a successful collisions. The general trend for the concentration is the rate doubles as the concentration doubles (they're directly proportionate).
Activation energy is the amount of energy required for the reactants to successfully react. The reactants need a certain amount of energy, any extra energy increases they're chance of a successful collision.
I concluded the higher the concentration of particles, the greater the chance of a successful collision. My results proved as the concentration doubled, the rate also doubled. They also show the higher the concentration, the faster the rate of reaction.
The marble and hydrochloric acid reaction showed us that, when a solid reacts with a solution, the reaction goes faster if the solution (hydrochloric acid), is more concentrated. This is because the marble is a solid. Its particles are vibrating slightly, but cannot move around freely. The hydrochloric acid is made up of several different sorts of particles. It contains water molecules, H+ions and Cl-ions. These are all in constant motion. They are moving around freely.
For the reaction to occur, we predicted the H+ions must collide with the marble particles. The harder they hit, the more likely it is that the particles will react together. Anything that makes the acid and marble particles collide more often, or collide more violently, will speed up the reaction. This prediction was correct
A more concentrated acid has more acid particles per cubic centimetre. So the acid particles will collide with the marble more often.
In a lump of marble (calcium carbonate), only the particles on the surface can come into contact with the acid. So only they can react. If you break the marble apart, more of it can react (although it isn't the surface area that we are measuring, it is the concentration).
In general, we conclude, reactions go faster when the concentration of reactants is increased. Therefore, the reactant with the highest concentration (50cm³acid, 0cm³water reacted the fastest.
A chemical reaction cannot happen unless particles in the reacting substances collide with each other.
Reaction rate=change in mass (concentration) of a substances
Time taken
In general this experiment has proved, reactions go faster when the concentration of reactants is increased.
ANALYSIS
After analysing our graphs and results table, we have noticed many trends
EVALUATION
Overall our whole experiment went well. We carried out the experiment precisely and safely. We carried out all the safety procedures, like wearing goggles and an apron. Luckily no accidents happened.
Our results were very accurate. We repeated our experiment four times to gain accuracy. When noting our results we noticed the results were very close in each test. This showed our experiment was very accurate, and we rarely got anomalies.
Overall our method was suitable. School equipment is hardly the most reliable, but it was all we had. We made the best of the equipment available. We sometimes had trouble with operating the inverted measuring cylinder. We had to ensure no oxygen escaped or entered the cylinder. This was quite hard, therefore resulting in some unfair results.
If I was to do this experiment again I would probably make it more accurate by using a Burette to measure the amount of gas given off, this would measure a lot more accurately the amount of gas given off. And also using smaller particles of marble chip so I could match up surface area and weight more accurately each time. I would like to then see if the concentration of acid is proportional to the rate of the reaction.
Also other things that I would like to investigate would be the experiment of time against amount of gas produced to show at which points the rate of reaction was at best and the curve/line of reaction. I would like to also investigate other factors, which affect the rate of a reaction like temperature and surface area to see how they affect the rate of a reaction.
Some other areas in the experiment that I feel I could have improved on were factors like, controlling the stopwatch. There is lots of room for human error here. But the inaccuracies due to them were negligible because I paid close attention to these during the experiment.
From analysing our results and graph, we can see they follow a certain trend. Also, all safety precautions were taken. We tried our very best to keep the experiment as fair as possible, by controlling certain variables.
There are some possible causes for our anomalies. One being, when washing the conical flask, some water may have remained in the flask, resulting in slight dilution of the acid.
The measuring cylinder wasn't long enough and so we couldn't take the last two measurements, as we had run out of space. The measurements on the inverted tube only went up to 50 cm³.
To get the reaction going, we sometimes had to shake the flask.
Our results and graph show, the higher the concentration the more volume of gas released. The more gas released tells us the faster the reaction. Therefore, the higher the concentration, the faster the rate of the reaction.
By doing this experiment in a school laboratory our resources were limited. This includes, certain equipment, time (to carry out the practical) and space. We would sometimes get confused whether we had added the acid to the flask yet, (as acid can be mistaken for water). Overall our evidence wasn't limited to draw a firm conclusion. Our results and graph clearly show this trend and does help us draw a firm conclusion.
SOURCES
. My head
. My dad's head
.'Biology today'-book
. BBC bitesize-website
