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

Controlled Assessment - Fertlilisers Research

Extracts from this document...

Introduction

Fertilisers Fertilisers are made from ammonia and are used in modern farming as they increase crop yield. The three main fertilisers made from ammonia include, ammonium nitrate, ammonium sulphate and urea. How are they manufactured? Fertilisers are made by the reaction of an acid and an alkali. The preparation of a fertiliser in a lab involves the following equipment: a measuring cylinder to measure the volume of a particular acid, a burette to add an alkali to the acid to try and make the solution neutral and a filter funnel to remove the solid crystals of fertiliser from the solution. The pH (power of hydrogen) value of the solution can be measured by taking samples while using universal indicator. In our examples; ammonia is reacted with nitric acid to make ammonium nitrate and ammonia is reacted with sulphuric acid to make ammonium sulphate. [2] NH3 + HNO3 � NH4NO3 Ammonia + Nitric Acid � Ammonium Nitrate NH3 + H2SO4 � (NH4)2SO4 Ammonia + Sulphuric Acid � Ammonium Sulphate When these fertilisers are manufactured in a factory the ammonia and the acid are pumped into a mixing vessel, where the solution is neutralised. ...read more.

Middle

- Urea usage involves little or no fire or explosion hazard. - Urea manufacture releases few pollutants to the environment. - Urea has the highest nitrogen content, at 46%. This percentage is much higher than other nitrogenous fertilizers available in the market. - The cost of production of urea is low because carbon dioxide, required for its manufacture, can be easily obtained from crude naphtha. Disadvantages of urea: - Urea is very soluble in water, and hygroscopic water (hygroscopic water creates a thin layer surrounding individual soil particles, which makes water unavailable to plants), and it therefore requires better packaging quality. - It is not as stable as other solid nitrogenous fertilizers. It decomposes even at room temperatures, particularly in a humid atmosphere. It releases ammonia and carbon dioxide into the air. - If urea contains impurities more than 2%, it cannot be used as a fertilizer, since the impurities are toxic to certain crops, particularly citrus. ...read more.

Conclusion

[6] Specific heat capacity for the acids: Nitric acid = 1.74 J/g �C Sulphuric acid = 1.42 J/g �C How an acid reacts with an alkali in a neutralisation reaction: An acid and an alkali react to produce salt and water. This is usually an exothermic process. In general, acid and alkali reactions can be simplified to: OH- + H+ � H2O Acids are generally pure substances that contain hydrogen ions (H+) or cause them to be produced in solutions. Sulphuric acid is an example of this (H2SO4). In water, it breaks apart into ions: H2SO4 � H+ + HSO4 - In general, alkalis are defined as substances that contain the hydroxide ion (OH-) or produce it in solution. One example would be sodium hydroxide (NaOH). To produce hydroxide ions in water, the alkali breaks apart into ions: NaOH � Na+ + OH- Therefore, the ions from an acid and an alkali react to cancel each other out and produce a neutral solution. The resultant pH value will generally be pH 7 and this is shown as a green colour on universal indicator paper. ...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 Changing Materials - The Earth and its Atmosphere 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

4 star(s)

A 4 star essay with good detailed scientific knowledge of a fertiliser. Some more general information would improve the introduction but there is a good balance of advantages and disadvantages next. Good accurate detail to describe neutralisation.

Marked by teacher Patricia McHugh 08/04/2013

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 Changing Materials - The Earth and its Atmosphere essays

  1. GCSE Chemistry - Electrolysis Coursework

    CHANGE IN MASS AT CATHODE (grams) 5 11.824g 11.848g +0.024g 10 12.456g 12.485g +0.039g 15 12.942g 13.011g +0.069g 20 12.967g 13.050g +0.082g 25 13.872g 13.983g +0.111g AVERAGE TIME (MINUTES) AVERAGE CHANGE IN MASS (grams) 5 0.0235g 10 0.0405g 15 0.0690g 20 0.0810g 25 0.104g THEORETICAL RESULTS TIME (MINUTES)

  2. Chemical Reactions in the Kitchen

    Proteins are made of long chains of amino acids. The proteins in an egg are circular proteins. This means that the long protein molecule is twisted and folded and curled up into a more or less circular shape. A set of weak chemical bonds keep the protein curled up tight as it floats gently in the water that surrounds it.

  1. Thermal Decomposition Of Metal Carbonates

    Bubbles rise from the metal, a signal that hydrogen is being given off. Magnesium also reacts in this way. The fairly reactive metals such as iron and zinc don't react with cold water. They do however react with steam to give off hydrogen.

  2. Plastics- A Benefit or a Disaster? (Science research coursework)

    These smaller hydrocarbons are more useful as fuel because they ignite more easily. However alkenes are also useful as raw materials for making other substances, in particular polymers (plastics). Plastics are made by a process called polymerisation. This is when the small alkenes join together to form large molecules.

  1. Investigating The Reactivity Of The Metals Iron, Magnesium, Zinc, Copper And Calcium And Their ...

    Using the temperature probe it gave accurate readings of the results rather than a normal laboratory thermometer. It was clear to see from using the temperature probe that again as I predicted that calcium was the most reactive metal as it took the shortest time to displace hydrogen whereas copper

  2. I am investigating which supermarkets have the strongest plastic bags; I have tested this ...

    The bags continue to travel through the machine as they are separated and sealed as required. Most plastic bags are thrown away, often after a single use but sometimes they are re-used. Recycling of plastics after being used is possible, but plastic bags, in particular, are rarely recycled.

  1. chemistry of sulphuric(VI) acid

    oxide as catalyst. The temperature of the chamber is about 450�C and the pressure is 1 atmospheric pressure. The percentage yield for this reaction in the above conditions is 98%. 2SO2(g) + O2(g) 2SO3(g) (c) Conversion of sulphur trioxide to sulphuric(VI)

  2. The Electrolysis Of Copper (ii) Sulphate Solution Using Copper Electrodes

    This is even more evident at 1.35A where the point is closest to the best line of fit when it would be expected to be well above the true value due to the effect of heat on the rate of reaction.

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