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

GCSE: Patterns of Behaviour

Browse by
4 star+ (13)
3 star+ (49)
Word count:
fewer than 1000 (334)
1000-1999 (657)
2000-2999 (391)
3000+ (277)
Submitted within:
last month (1)
last 3 months (1)
last 6 months (1)
last 12 months (1)

Meet our team of inspirational teachers

find out about the team

Get help from 80+ teachers and hundreds of thousands of student written documents

  • Marked by Teachers essays 45
  • Peer Reviewed essays 15
  1. 1
  2. 2
  3. 3
  4. 4
  5. 56
  1. Marked by a teacher

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

    4 star(s)

    - Collision theory was introduces by Max Trautz and William Lewis in 1916. Chemists believe that the theory explains how the various factors affect reaction rates. It is believed that molecules are only able to react if they bump into each other. When molecules are colliding with each other it can lead to other theory's affecting this such as concentration, temperature and catalysts. The theory states that when molecules are colliding with one another atoms can break and new bonds form creating new molecules. There are molecules in gases and liquids which are always in constant motion colliding in millions.

    • Word count: 4377
  2. Marked by a teacher

    Investigation of the rate of reaction between Magnesium and Hydrochloric acid

    4 star(s)

    Advantages: 'Rate of reaction graphs' are easy to plot using the results from this method. It is the most accurate method because the mass balance is very accurate. Disadvantages: The gas is released straight into the room and if the flask is not covered by the cotton Wool properly, drops might escape from the flask which lowers the total mass of the solution unnecessarily. Name: Gas Syringe Description: This method involves the use of a gas syringe to measure the volume of gas given off. The more gas given off during a time interval, the faster the reaction.

    • Word count: 3932
  3. Marked by a teacher

    Rate of Reaction Chemistry Coursework

    4 star(s)

    This variable in my experiment must stay the same, if I want to achieve reliable results. It has to stay constant otherwise it would be unfair and the results wouldn't be reliable. I will keep it constant by using the same amounts of reactants for each experiment. I will have to decide on the amount of hydrochloric acid I use and the amount of magnesium I will use and keep them the same for every experiment that I do. If I do this I would have this variable controlled. Surface Area- Any reaction in a solid has to take place at the surface at the solid.

    • Word count: 4087
  4. Marked by a teacher

    Marble Chips and Hydrochloric Acid.

    4 star(s)

    To be sure I can rely on my results I will repeat he experiment twice or three times if necessary, because there is chance of inaccurate results for many reasons. I learnt from the trial experiments that it is quite hard to start a stopwatch, pour acid and stick a bung into a boiling tube all at the same time, so I will get someone to assist me while doing so. If the experiment goes on for a ridiculous time, I will cut it off.

    • Word count: 4637
  5. Marked by a teacher

    Hypothesis: some metal carbonates decompose more easily than others when they are heated.

    3 star(s)

    Use a pipette. Wash hands with cold water if lime water comes into contact with skin. It?s harmful. Can cause itchiness and pain. Wear goggles and take care when using it. If there is a spillage tell the teacher immediately. When not using the Bunsen burner use yellow safety flame. Don?t keep the boiling tubes on a blue flame for longer than 2 minutes as could break due to prolonged heat. Tie long hair up out of place to stop getting caught in flame Always follow lab rules.

    • Word count: 852
  6. Marked by a teacher

    How does the concentration of hydrochloric Acid affect the rate of reaction?

    3 star(s)

    The energy required to break these bonds is called the Activation Energy (EA) There are four main factors that affect reaction these are: * Temperature * Use of a catalyst * Concentration * Surface area Temperature When the temperature is increased the reactant molecules move around faster with a greater amount of energy. This means there will be more successful collisions because it is the amount of energy in the molecules that determines whether a reaction is more successful. More successful collisions resulting in reactants get used up quicker resulting in the reaction time decreasing.

    • Word count: 1638
  7. Marked by a teacher

    In this investigation we are going to measure the rate of reaction of marble and HCl when the concentration or surface area of marble is changed.

    3 star(s)

    We tested using different concentrations of HCl and different surface areas of marble so we could have a set of results to help us compare with our main results, to help us determine the accuracy of the results. Apparatus ? Small and medium marble chips ? 1M and 2M HCl ? Water trough ? Conical flask- where the reaction takes place ? Delivery tube and bung ? Two measuring cylinders- one to measure out HCl and the other to collect CO2 ?

    • Word count: 3941
  8. Marked by a teacher

    Rate of Reaction - Sodium Thiosulphate and Hydrochloric Acid

    3 star(s)

    close as reasonably possible, I will when doing this take into account surface tension and hence fill so the actual amount in the measuring cylinder is at 10ml not a little under as it may appear. I will then add (starting with 50ml descending in steps of 5ml to 20ml) sodium thiosulphate to the 50ml measuring cylinder. Following this I will add (starting with 0ml rising to 30ml in steps of five, in such a manner that the total volume of water combined with sodium thiosulphate Is always at 50ml)

    • Word count: 1516
  9. Marked by a teacher

    In my investigation I am going to look at how concentration affects the rate of reaction, and the reaction I am going to look at is Sodium Thiosulphate (Na2 S2 O3) and Hydrochloric Acid (HCl).

    3 star(s)

    When the "X" is obscured the reaction has went to the same point. Prediction I predict that the stronger concentration of sodium thiosulphate, the quicker the "X" will be obscured as there are more successful collisions occurring per second, which will mean a greater rate of reaction. The higher the concentration will mean more particles present in the same volume, which will lead to more collisions and therefore more successful collisions which increases the rate of reaction Low Concentration - Few Collisions High Concentration - More Collisions I predict that more water added to the solution of Sodium Thiosulphate and Hydrochloric Acid, the longer "X" will take to be obscured.

    • Word count: 1580
  10. Marked by a teacher

    I measured the effect of concentration on the rate of reaction. The reactants were Sodium thiosulphate and Hydrochloric acid.

    3 star(s)

    The chances of collision are higher when the concentration is higher. For many reactions that involve liquids or gases, the increase of concentration on the reactants will increase the rate at which the reaction takes place. The point at which the reaction starts is called the energy barrier. When this energy barrier is reached, the chemical bonds in the reactants can be broken, which allows them to proceed from reactants to products. The main outcome of this experiment found, is that the higher the concentration of sodium thiosulphate, the faster the rate of reaction becomes.

    • Word count: 1255
  11. Marked by a teacher

    Rates of reaction between hydrochloric acid and magnesium

    3 star(s)

    Therefore more reactant particles will have enough energy to react. Consequently the number of successful collisions increases. Concentration When increasing the concentration of reactants, the rate of reaction rises. If there are more particles in the same space of volume, the rate of successful collisions increases. The rate of reaction will change as the reaction progresses. When the reactants are used up during the reaction, the concentration of reactants decreases. Meaning particles collide less frequently and the reaction rate decreases. Exothermic and Endothermic These are reactions that transfer energy to the surroundings. The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to become hotter.

    • Word count: 2649
  12. Marked by a teacher

    For my experiment I am finding out the effects on the reaction rate when magnesium is put into different concentrations of hydrochloric acid.

    3 star(s)

    Therefore changes in the temperature could impact the reliability of the results. The concentration of hydrochloric acid is a factor that, I intend on changing by adding varying amounts of water to dilute the acid. The concentration, if changed, will also cause a doubt in the reliability of the results. This is due to there being less or more molecules of hydrochloric acid than when the concentration is not altered. In my experiment it is a factor that I wish to change and monitor the effects in doing so (independent variable).

    • Word count: 5878
  13. Marked by a teacher

    The effect of concentration on the rate of reaction of Magnesium with Sulphuric Acid.

    3 star(s)

    Activation energy is the minimum energy required before a reaction can occur. There are several factors that can increase or decrease the chance of a successful collision. The factors that affect the rate of the reaction are; * Temperature - when we increase the temperature, we give the particles energy, which makes the particles move faster. Therefore the particles collide more and they are more likely to have the correct activation energy. The greater the temperature, the faster the rate of a reaction. * Surface Area - when we increase the surface area of the reactants we increase the number of particles available for a successful collision.

    • Word count: 2191
  14. Marked by a teacher

    Rates of reaction of agar with different HCL concentrations

    3 star(s)

    Reactions that involve collisions between more than two species are going to be extremely uncommon. It is clear to understand that if you have a situation involving two species they can only react together if they come into contact with each other. Firstly they have to collide then they may react. Why "may react"? It isn't enough for the two species to collide - they have to collide the right way around, and they have to collide with enough energy for bonds to break in the reactants. (The probability of all this happening if your reaction needed a collision involving more than 2 particles is remote.

    • Word count: 3109
  15. Marked by a teacher

    What affects the rate of a reaction? The reaction I will be investigating is the reaction of marble chip (Calcium carbonate) with hydrochloric acid.

    3 star(s)

    In my experiment I chose to use concentration as my independent variable. The reason why I didn't choose temperature was because; I didn't have the facilities to control the temperature precise enough that it would be an accurate test. The reason why I didn't choose catalyst was because; I wasn't able to get my hands on a catalyst that would be suitable and it would cost too much for me to buy a catalyst. So this left me with surface area and concentration, the reason why I didn't choose surface area was because; with the resources available that would be

    • Word count: 3532
  16. Marked by a teacher

    Chemistry rate of reaction coursework

    3 star(s)

    To counter this a water-bath will be used as I can keep the temperature at a constant. So my aim is to change the concentration in the Sodium Thiosulphate by adding water and taking away Sodium Thiosulphate gradually. The reaction of the experiment will be as follows: Sodium Thiosulphate + Hydrochloric Acid Na2S2O3 (aq) + 2HCL (aq) For my preliminary investigation I used the variable concentration to give me an idea of the range of results and what to expect in my final investigation.

    • Word count: 1297
  17. Marked by a teacher

    Reaction Rates Investigation

    3 star(s)

    3 strips, 1cm each and 1 strip at 3cm. Here is a diagram for the most suitable method to use the apparatus we considered. We chose this method because in my opinion it is quicker to set up leaving more time for our actual experiment as we had limited time to complete it. The other apparatus involved a Burette in a clamp stand which was in my opinion just as effective as the more simple method of an upturned measuring cylinder which was a simple process to set up.

    • Word count: 2984
  18. Marked by a teacher

    Rates of Reaction Practial

    3 star(s)

    - Calcium Carbonate Powder (5g) - Hydrochloric Acid 1M (100ml) - Spatula - Accurate Scale - Stopwatch Method: 1. Collect all of the equipment and measure 5g of each size of surface area of Calcium Carbonate with a spatula. 2. Collect 100 ml of Hydrochloric Acid into one of the 400ml beakers. 3. Place the other beaker on the scale and then set the scale measure to zero. Pour the 100ml of HCl into the beaker on the scale. 4. Hold a stopwatch in one hand, and place the large CaCO3 chips into the beaker containing HCl. Start the stopwatch as soon as the chips contact with the surface of the acid.

    • Word count: 839
  19. Marked by a teacher

    Rates of Reaction

    3 star(s)

    Apparatus/ Materials: * 20ml of 0.5M HCl * 20ml of 1M HCl * 20ml of 2M HCl * 20ml of 3M HCl * 20ml of 6M HCl * 10g of Calcium Carbonate Powder * 1 Gas syringe * 5 200ml beaker * 1 25ml measuring cylinder * 1 rubber band Method: 1. Measure five 2g CaCO3 powder separately in five different 200ml beakers. (recommended to weigh with a scale (g)) 2. Measure a 20ml of HCl (with a measuring cylinder and use a pipette for small modifications)

    • Word count: 2546
  20. Marked by a teacher

    Lab report rates of reaction

    3 star(s)

    0.5 mole. If this is obstructed then concentration will play its part in the rate of reaction. Note: We should try our best to keep factors that affect the rates of reaction constant. For example temperature and pressure and concentration. This is because if they are differed they would hugely impact our results as they serve as catalysts to the reaction. So we should make sure temperature is constant, The same sizes fo flasks and bongs are used (so pressure is constant) and lastly we should make sure the concentration of the acids are left at 0.5 moles.

    • Word count: 2182
  21. Marked by a teacher

    Science Rate Of Reaction

    3 star(s)

    The effects of surface area: The effects of concentration: The effects of temperature: 2mph 25mph In order to calculate the rate of reaction I will use this formula: 1 Average time When sodium thiosulphate solution reacts with hydrochloric acid a solid is formed. The time taken for a certain amount of sulphur to form can be used to indicate the rate of reaction. In this experiment the effects of the concentration of the sodium thiosulphate on the rate of reaction is investigated.

    • Word count: 671
  22. Marked by a teacher

    Rates of Reaction

    3 star(s)

    I will be able to tell when the reaction is complete because the solution will turn opaque enough to obscure the cross underneath the flask from view. Controlled -The volume of hydrochloric acid will be kept the same throughout the experiment because if it is changed it may affect my results. Also the concentration of the hydrochloric acid will be kept the same. -The volume of sodium thiosulphate solution, I will change the concentration of the solution, but not the volume because this may affect my results.

    • Word count: 1315
  23. Marked by a teacher

    How does varying the concentration in a reaction affect the rate of reaction?

    3 star(s)

    a result of the experiment, I have decided to stop timing my actual experiment when the amount of hydrogen produced reaches 20 cm3. This is because I think it will give me enough time to stop the stopwatch quickly enough on the higher concentrations and will not take too long to produce the hydrogen for lower concentrations. Experiment 2 The aim of this experiment was to find out how the temperature of the reaction will change during my experiment. I put 3cm of magnesium into a conical flask which had 100cm3 of 2M of HCl.

    • Word count: 1835
  24. Marked by a teacher

    Chemistry: Practical Investigation

    3 star(s)

    Catalysts affect the rate of reaction by providing an alternate route with a lower activation energy requirement, meaning atoms / molecules don't need to be travelling so fast. I am able to keep the temperature at room temperature due to central heating, and there are no catalysts for this reaction. The surface area is harder to control as they do not all have precisely the same surface area, however I weighed 3 chips until they added up to 1.1g. Surface Area: 2 Temperature 2 Concentration 2 Preliminary Method Firstly I set up the apparatus as shown under the apparatus but

    • Word count: 1391
  25. Marked by a teacher

    rate of reaction

    3 star(s)

    We should also dispose the mixture of chemicals of down a well-flushed sink. Equipment * Hydrochloric acid * Sodium thiosulphate * A paper with a black cross drawn on it * A conical flask * 2 measuring cylinders * 1 stopwatch * A pair of goggles Collision Theory The collision theory explains how a higher amount of collisions in a system, cause more combinations of molecules to occur. Moreover, how this affects the reaction to go faster, and the rate of reaction to become higher. Only a small part of the overall collisions cause chemical change; these are called successful collisions.

    • Word count: 1572

Marked by a teacher

This document has been marked by one of our great teachers. You can read the full teachers notes when you download the document.

Peer reviewed

This document has been reviewed by one of our specialist student essay reviewing squad. Read the full review on the document page.

Peer reviewed

This document has been reviewed by one of our specialist student document reviewing squad. Read the full review under the document preview on this page.