The rate of a chemical reaction is a step of how fast the reaction takes topographic point. So, a rapid reaction is completed in a short clip. Some reactions may be really slow, e.g. the rusting of steel. A chemical reaction merely occurs when atoms collide with each other. Atoms which move fast are more likely to clash with each other ; you can make this by heating them up ( raising temperature ) . This means more atoms collide with each other every 2nd, so the rate of reaction additions. There are more atoms of hydrochloric acid atoms if there is a higher concentration of them. More atoms means there will be a higher sum of hits so the reaction should be fast.
Other factors that affect the rate of reaction are ; temperature, A accelerators and surface country. Temperature affects reaction rates as itA dictates how much energy the atoms in a substance have, at higherA temperatures atoms have more energy and so travel more rapidly andA collide more. As the atoms are traveling faster the collisionsA between them have more energy, this means that they are more likely toA make a reaction and so reaction rate additions. Catalysts lower theA sum of energy needed for a hit to be successful, so adding aA accelerator to a reaction increases the sum of successful collisionsA and therefore additions reaction rates. The larger the sum ofA surface country, the faster the reaction rate is.
Independent Variable= Hydrochloric acid concentration
Dependent Variable= Time taken for Mg to fade out
To look into the reaction clip between Mg and hydrochloric acid.
I think that my consequences will demo that the hydrochloric acid with aA molar concentration of 2 will complete responding the quickest because it is theA strongest hydrochloric acid and I predict that the slowest experimentA to complete reacting will be the 0.4 molar strength of hydrochloricA acid. I think that the consequences will travel slower and slower the nearerA they are to the 0.4 strength of hydrochloric acid. The ground that theA experiment with hydrochloric acid at 2 grinder will fade out theA Mg thread faster is because it is of a stronger concentrationA and so the molecules in the hydrochloric acid move faster and so reactA with the Mg thread quicker.
To do certain my experiment was a just trial, I had to maintain these factors the same:
Surface country of Mg
Volume of acid used ( 10ml )
Used the same type of beaker ( 80ml )
Length of Mg ( 1cm )
Clean the Mg with emery paper before the experiment
Temperature of the hydrochloric acid
The factor of which I will alter is the concentration of the hydrochloric acid.
I used the undermentioned equipment:
80ml beakers ( x5 )
Equal strips of Mg ( x5 )
A measurement cylinder
I will necessitate to do my experiment every bit safe as possible. It will be safe for me and other pupils around me. Precautions will be made if person is harmed, such as there will necessitate to be a first assistance kit nearby & A ; accessible, besides a H2O pat in instance acid touches the tegument or eyes. This is what I will necessitate to make:
Care in utilizing glasswork as when broken is crisp and can cut the tegument
Wear safety goggles as I am utilizing concentrated hydrochloric acid
Care in returning all the equipment at the terminal of the experiment
Care to eyes and skin asset to be cognizant of other pupils around the category
The acid that we are utilizing in this experiment is of 1.0 molar strength, A which is strong plenty to at least cause annoyance to the tegument ifA spilled on it ; the hydrochloric acid would besides do annoyance toA the eyes and oral cavity if of all time spilled into those. Another hazard is thatA Mg is flammable particularly if in pulverization signifier, but we are usingA it in a thread signifier and we are non utilizing any fires in any portion of theA experiment. The gas which is given off from the reaction betweenA hydrochloric acid and Mg thread is hydrogen which is aA flammable gas.A
We will cut down the hazard of these jeopardies by have oning protective eyewearA for illustration research lab goggles, we will besides mensurate out theA hydrochloric acid pouring off from the organic structure, over the sink. We willA non be utilizing fires in our experiment so the hazard is reduced from theA H and Mg but still other experiments could be usingA fires so we will still hold to be careful and do certain to remain awayA from any other experiments utilizing flames.A
First, we had to record ( in a tabular array ) the clip taken for a 1cm Mg ( Mg ) strip to wholly fade out in a beaker incorporating hydrochloric acid ( HCl ) . I had five different concentrations of the hydrochloric acid: 1.0m, 1.2m, 1.4m, 1.6m, 1.8m and 2.0m. I put 10ml of hydrochloric acid in a glass 80ml beaker, and so one by one I began seting the Mg strips into each beaker and clocking the continuance taken for the Mg to fade out. The first thing we noticed is that the lower the concentration of the acid, the longer the Mg took to fade out. We were seeking to happen out how the concentration of the acid affected the velocity of which the Mg dissolves.
The equation for this experiment was:
Magnesium + Hydrochloric Acid a†’ Magnesium Chloride + Hydrogen
Mg + 2HCl a†’ MgCl2 + H2
The theory that we use to explicate how different variables change theA rate of reaction is called the hit theory.A
For a reaction to take topographic point, the atoms of the substances that areA responding have to clash. If they collide, with adequate energy thenA they will respond. The minimal sum of kinetic ( motion ) energy thatA two atoms need if they are traveling to respond when they collide isA called the activation energy.
I needed to roll up: Safety goggles, five 80ml beakers, a lab coat, a measurement cylinder, and a pipette. Safety goggles were really of import because of the chemicals we were utilizing. Hydrogen gas was besides being released, which is extremely flammable so we had to be cognizant if we were to light anything near it.
This was the method I used:
Put on safety goggles and a lab coat
Collect ( 80ml ) beakers ( x5 )
Roll up a pipette and a measurement cylinder
Measure out 10ml of hydrochloric acid with a pipette
Let go of the acid into the beaker
Make sure we have a stop watch at the ready
Collect Mg strips
Put the Mg into the acid and do certain at the exact same clip the halt ticker has started
The H produced makes the reaction mixture effervesce ( fizz ) . The faster the reaction, the shorter the clip taken for the effervescence to halt.
My consequences may non be wholly accurate, as the individual utilizing the halt ticker may non respond rapidly plenty to halt the clip. Besides the sum of millilitres put into the cylinder may non be exact due to the truth of the setup. Although the consequences are likely to be dependable as we used the same type setup for each experiment, and concentration we tested on, we followed the method precisely the same for each repetition
We used the same method for all five different concentrations of the hydrochloric acid. We used the same pipette and mensurating cylinder but made certain they were washed with H2O and so dried ready for the following concentration.
We repeated the whole experiment for a 2nd clip to derive a better penetration of our consequences ; this would besides let us to descry outlier ‘s and discourse how we got them. If we found an outlier we repeated the reading.
We so worked out an norm between both of our consequences, although we did non happen any outlier ‘s so our norm was n’t affected.
Time taken for the Mg to fade out ( s )
Hydrochloric acid concentration
Average calculated from both experiments
My graph which is attached to this papers, it shows that the incline of the curve was negative due to the immense lessening in the seconds taken for the Mg to fade out ( negative correlativity, as you increase the concentration of hydrochloric acid, the sum of seconds to fade out lessenings ) . As seen in my graph the difference within the sum of seconds from concentrations 1.0m and 1.2m is the biggest difference of 51.45 seconds. This similarity continues all the manner through until the last two concentrations have a little difference of merely 4.3 seconds.
To reason I realised the higher the sum of concentration in the beaker, the faster the Mg dissolved. A scientific account to this would be that there were more atoms in the beaker intending the there was less infinite ensuing to larger sum of hits. More hits – The rate of reaction depends on the rate of successful hits between reactant atoms. The more successful hits there are, the faster the rate of reaction. Surface country could hold affected the experiment, but as these factors were controlled my consequences were n’t affected.
I predicted that the higher the concentration the faster the reaction.A The ground for this is as the concentration increased the rate ofA reaction increased. The line demoing the consequences of 1.0 molar acid isA the steepest. The reaction is faster with stronger acid because itA contains more acerb atoms. The greater figure of acerb atoms theA more opportunities of a hit between acid and Mg particlesA therefore the faster the reaction. The strongest acid besides producesA the most gas because it contains more reactant acid atoms. You can see from the graph below the higher the concentration of acidA the faster the rate. There is now grounds to endorse up my prediction.A
My hypothesis has been proven right, in that beforehand I believedA increasing the concentration means that we have more atoms in theA same volume of solution. This increases the opportunity of collisionsA between reactant atoms, ensuing in more hits in any givenA clip and a faster reaction. This can demo us a general regulation aboutA concentrations and rates of reactions.
During my probe there is a possibility that I may hold come across mistakes. These mistakes were linked to my measurings. The timing of the Mg dissolution in the hydrochloric acid could hold plus or minus a 2nd due to the reaction velocity of the individual clocking it. Besides the ( measurings of the hydrochloric acid volumes were accurate to +/- 1cmA? .
Many of the mistakes are down to human opinion,
Measuring of volumes
Reaction velocity of the timer
From the consequences in the tabular array and the graph we can see a steadyA addition in the rate of reaction as the concentration of the acidA increases. This complies with my anticipation. The graph shows thatA there is an addition in the rate of reaction as the concentrationA additions because the graph has its largest gradient or it isA steepest at this point. ) . Besides we can see that as the reactionA continues the concentration of the reactants lessening and so does theA rate of the reaction as we can see the diminishing gradient on theA graph steadily falling and coming to a halt when the reaction isA complete and the Mg has wholly disappeared.A
I think my experiment went good as a whole. I could hold perchance improved the truth of some of my consequences I could hold used moreA concentrations of acid to see if the form carried on as it didA antecedently or changed, I could hold repeated the readings more timesA to do them more accurate. In some occasions I could hold done things to do my experiment a fairer trial. I could hold repeated my experiment at least one more clip to increase dependability. I could hold perchance concentrated more on my experiment than get distracted by equals. If I repeated this experiment I could hold tried look intoing other facets of the experiment which could alter the rate of reaction. One illustration could be altering the surface country, the concentration of acid and force per unit area can impact the reaction. I could hold besides tried utilizing different acids, such as sulfuric acid.
Different metals could let me to look into their ( relativity ) responsiveness and the affect this has on consequences and reaction rate. The reaction could associate to a existent life state of affairs, such as if person were to walk into a crowded country, there would be more hits instead than if the topographic point was empty. Therefore people in the country acquire more annoyed, which consequences in even more hits, hence this illustration relates to the rates of reaction.
The consequences lined up really good on theA graph with a really near curving line of best tantrum that all the resultsA autumn straight onto or really close to with merely two off the line andA merely 1 2nd off. This backs up the consistence and dependability ofA the consequences, which makes my grounds good plenty to back up a firmA conclusion.A
To better my cognition of reaction rates I could and howA concentration affects them I could carry on experiments utilizing differentA metals and different acids. I could besides utilize a larger scope ofA concentrations to widen my consequences and give me more grounds. UsingA smaller spreads between concentrations would besides foster my grounds asA it would better my rate graph leting me to pull a more accurateA line of best tantrum therefore leting me to do more accurate estimatesA for consequences of concentrations non yet tested.A
And it could hold been improved by the repeat of eachA concentration 3 times ; alternatively of the one clip I was able to carry on, A to extinguish all anomalous consequences. As from 3 sets of readings, anA norm can be calculated which will supply a more dependable consequence asA it is based upon 3 readings, non merely the one reading which may beA wrong.A
The probe could be done utilizing one variable and hence haveA a set of consequences which were related in some manner. The variables thatA could be used are: A
Particle size/surface areaA
These variables can be used because: A
The more concentrated the reactants, the greater the rate ofA reaction will be. This is because increasing the concentration of theA reactants increases the figure of hits between atoms and, A hence, increases the rate of reaction.A
When one of the reactants is a solid, the reaction must take placeA on the surface country of the solid. By interrupting up the solid intoA smaller pieces, the surface country is increased, giving a greater areaA of hits to take topographic point and so doing an addition in the rate ofA reaction.A
An addition in temperature produces an addition in the rate ofA reaction. A rise of 10° C about doubles the rate of reaction.A When a mixture of substances is heated, the atoms move faster.A This has two effects. Since the atoms are traveling faster they willA travel greater distance in a given clip and so will be involved inA more hits. Besides, because the atoms are traveling faster aA larger proportion of the hits will transcend the activation energyA and so the rate of reaction increases.A
Looking at the set of consequences obtained, you can clearly see that theyA all follow the expected form. This is pattern suggests that theA reaction rate addition when the concentration of the acid increasesA because if you increase the concentration of the acid you areA presenting more atoms into the reaction which will in turnA produce a faster reaction because there will be more collisionsA between the atoms which is what increases the reaction rate.A
There will ever be ways in which you can better yourA probes and the same thing goes to my probe. EveryA clip I washed a trial tubing or a measuring cylinder, I did non dry itA before utilizing it. This may hold affected the rate of reaction, as waterA would thin the acid. To better my consequences, I could dry the testA tubings and the measurement cylinder after they are washed to preventA diluted acids. The size and weight of the Mg would haveA affected the rate of reaction. The experiment could be improved byA measurement, seting and weighing the Mg threads so they allA are the same size and weight.A