• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The effects of concentration on reaction rates

Extracts from this document...


John Saunders (11R) The effects of concentration on the rate of reaction between magnesium (Mg) and Hydrochloric acid (HCl). Introduction: In this experiment, I am going to find out what happens when different concentrations of hydrochloric acid are mixed with the same amounts of magnesium. The probable outcome of this is that the reaction will be more vigorous to start with, meaning the reaction would end up being completed faster, if the concentration was to be higher than normal. This would happen because there would be more atoms of hydrogen and chlorine in a higher concentrated solution, to react with the magnesium. As you can see, the circles that represent the hydrogen and chlorine atoms of the hydrochloric acid find it a lot harder to fit inside the right-hand rectangle, that is the same area as the left rectangle (the rectangles representing the solution of acid). This means that the right-hand rectangle is more concentrated, as the hydrogen and chlorine atoms take up more space. If a piece of magnesium were to be placed in the rectangles, then the more vigorous (and faster) reaction would take place in the right-hand rectangle. This is because the magnesium would be confined to the (smaller) area where there aren't hydrogen or chlorine atoms, so the collision rate is likely to be higher. ...read more.


times descend), I can't analyse the results like this. This is because the different concentrations vary too much, meaning that the differences between each concentration and the preceding one are different depending upon which result you look at (e.g. 0.2M - 0.1M = 0.1M; but 4M - 2M = 2M difference). This is why I have set the 'x' axis on my graph 9the concentration), to reflect this, by using a scale, whereby every 10 little squares represents 0.5M. Analysis: These results show trends, but not in the way I expected them to. The results were pretty accurate, I felt, because apart from one minute at the maximum, the results for each test and its repeat were nearly the same. The plot of results on both graphs representing the two tests and the average results all have the same trends, only these results weren't proportional unlike I predicted them to be. There are basically two proportional lines, involving the points 0.1, 0.2 and 0.5 mole concentrations, and the 1, 2 and 4 mole concentrations. For some strange reason, somewhere between 0.5 and 1 mole concentration, the line's sharp gradient declines, so it looks as if the reactions doesn't have the same speed in contrast to the concentration of HCl it's in. ...read more.


This could have been done either by redoing the tests with more magnesium (a longer strip), or by using less HCl. I would have done this, but the tight time limit meant that I couldn't redo all the tests that I have already done in time, before realising this. Another way my results could have been affected is that because the 0.1 reading took a long time to complete, meaning that I may not have noticed that the reaction had finished straight away. I don't think this happened, though, so I'm not too worried about this. Finally, and this occurred in my second test which could indeed explain my ringed faulty result, I admit, time got the better of me and so I didn't wash out my measuring cylinder out after measuring each concentration of acid. I may have measured smaller concentrations first and these concentrations could have mixed with the one I was using then to not give the mole that I said I was using for this test. To get over this problem, I could either have rinsed out the cylinder before measuring each concentration, or even by sharing cylinders with other people, of which each cylinder would only be used for one concentration. Overall, despite these problems, I don't think I will have made a bad attempt at the experiment, because the results were similar both times and they did follow a trend on my two graphs. 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Patterns of Behaviour section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a teacher thought of this essay

3 star(s)

This was a routine task requiring only limited precision to be completed. It used basic equipment and collected a limited amount of data. The data that was collected has limited reliability due to the low nature of repeats. Some comments were made in relation to the accuracy of the data however they were not supported with enough experimental evidence to make them reliable. Some scientific vocabulary was used. Overall this is a three star scientific report. Improvement have been suggested throughout

Marked by teacher Cornelia Bruce 18/03/2013

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Patterns of Behaviour essays

  1. Marked by a teacher

    The Effect of Concentration on the Rate of Reaction between Magnesium [Mg] and Hydrochloric ...

    4 star(s)

    Method 1. We got the equipment needed to proceed with the experiment. (BOWL, DELIVERY TUBE. CONICAL FLASK, BEEHIVE SHELF, STOP WATCH, HYRDOCHLOIC ACID, MAGNESIUM, GOGGLES AND MEASURING CYLINDER) 2. We filled up the bowl allowing the beehive shelf to be submerged under the water so we are able to put the delivery tube through it.

  2. Marked by a teacher

    Investigation of the rate of reaction between Magnesium and Hydrochloric acid

    4 star(s)

    47 210 50 240 53 Eighth test: Hydrochloric acid 0.8 molar (50 ml) and calcium carbonate powder (0.5 grams) Hydrochloric acid 0.8 molar (50 ml) and calcium carbonate powder (0.5 grams) Seconds (s) Gas produced (cm3) 0 0 30 37 60 46 90 49 120 51 150 52 180 53

  1. The effects of caffeine on reaction time

    When caffeine is consumed, to a nerve cell, caffine looks like adenosine, so caffeine binds to the adenosine receptors. The cell cannot see adenosine anymore because the caffeine is taking up all the adenosine receptor sites. So, instead of slowing down the cell activity, it speeds up.

  2. Factors Affecting the Rate of Catalytic Decomposition of Hydrogen Peroxide.

    particles, and therefore twice as many collisions should occur. This means that when the concentration doubles, twice as many collisions between the H202 and Mn02 particles occur and the rate of the reaction also doubles. My Prediction: If there are double as many particles, there is double the chance of a collision between the hydrogen peroxide particles and the manganese dioxide (catalyst)

  1. To Compare the Concentration of the Enzyme Catalase in Plant v. Animal v. Fungal ...

    The tissue was then weighed on a top-pan balance, after which 5g of the tissue was place into a test tube. Then 5cm3 of pH7 buffer was added to the test tube using a pipette. The apparatus was set up as above.

  2. Rates of reaction between Magnesium and HCl.

    I have some background knowledge on rates of reactions from preliminary work particularly during G.C.S.E. chemistry. In this experiment I will react a known mass of magnesium with an excess of hydrochloric acid (HCl) to produce hydrogen gas as shown.

  1. To determine the rate law for a chemical reaction among hydrogen peroxide, iodide and ...

    dm3 / [(70+30+25+5+5+5+10)/1000 dm3] = 3.33x10-4 mol dm-3 The reaction rate ratio (rate F/ rate A) for reaction mixtures F and A is: Rate = 1/ time Rate F= 1/56= 0.0179 Rate A = 1/172 = 0.00581 The reaction rate ratio (rate E / rate A)

  2. How does changing the concentration of the Hydrochloric acid affect it reactions with Magnesium?

    To reduce the heat produced from the experiment a water bath will be used throughout the experiment. This will control the temperature. Solutions: I have decided to use 1 mole for the concentration of acid. This is because 2 moles was too reactive and there were not enough results to collect due to the rapid rate of reaction.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work