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

formula for copper sulphate

Extracts from this document...


Determination of the formula of Hydrated Copper Sulphate Crystals. Skills A and E Experiment 1 Mass of crucible: 28.54g Hydrated Copper: 2.40g Total: 30.94g After heating, Hydrated Copper = 1.60g Reheat after 5 minutes, mass: 1.59g Reheat after 5 minutes, mass: 1.58g Reheat after 5 minutes, mass: 1.57g final mass of hydrated copper Aim: Calculate the percentage by mass of water of crystallisation present in the crystals. 2.40 - 1.57 = 0.83 / 2.40 x 100 = 34.6%. Experiment 2 Aim: Use equations 1 and 2 to deduce the relationship between the number of moles of Cu2+ and the number of moles of S2O32- . Results Table Burette Readings Trial (cm3 ) Initial (cm3 ) Final (cm3 ) Volume used cm3 (final - initial) 23.75 0.00 23.90 23.90 0.00 23.85 23.85 0.00 23.80 23.80 0.00 23.90 23.90 Average titre Volume (cm3) : 23.86 It is a 2:2 ratio; the number of moles of Cu2+ is proportional to the number of moles of S2O32- . Sodium Thiosulphate: Number of moles = concentration x volume / 1000 0.1 x 23.86 / 1000 0.0024 Aim: Calculate the percentage by mass of Cu2+ in your sample of copper sulphate crystals. Copper Ion: Mass = Number of moles * Relative formula mass 0.0024 * 63.5 0.1524grams * 10 = 1.524 / 5.80 * 100 = 26.3% Analysis of the results from both experiments (Skill A) ...read more.


Also, using pipette filler, air bubbles may have been formed at the tip as the solution was being drawn. This would have affected the quantity of solution being titrated, as it would have appeared to be less. If air bubbles do occur, then the solution should be released back and the process should be started again. In terms of procedural errors for Experiment 2, if the reading is not taken from the bottom of the meniscus, then an inaccurate reading is taken, so this would lead to an error being created in the procedure. Also, in terms of the end-point of the experiment, it is every easy to over-titration and this may have been the case, so end-point should be approached with care and the 30 seconds wait should be kept to make sure that the colour change is permanent. In addition, for the procedural error of Experiment 1, it was not repeated more than once so therefore, an average could not be found which mean that the one experiment that was conducted had to be taken as the true final mass. Also, the weighing scale measures to a degree of two decimal place; if it measured to four, this may have made the experiment more accurate. ...read more.


This shows that the titration method is more accurate. The mole ratios remained the same because of the relationship between the water and copper, however, there were small variations in the trials which could have been caused by the lack of drying of the Copper or improper calibrated weighing scales. Looking at the method critically, with titration, over-titration has to be avoided. The colour change observed at the end is a little requirement but this has to be performed carefully so that it does not affect the result. In addition, the stir motor should not be allowed to run too fast because splashing may occur therefore, the reagents will not mix in. Whilst saying this, the burette should be centered over the flask so that drops fall directly into the solution otherwise, drops may fall to the side of the flask affecting the volume, thus, the reliability. A main improvement that could be implemented had the equipment been available would be to completely automate the experiment to remove the degree of human error. This would involve using very accurate robotic machines to precisely measure the amount of copper sulphate used and the mass of everything. It would also heat it for the exact amount of time to prevent burning (oxidization) or to not be fully dehydrated. Reference http://www.avogadro.co.uk/miscellany/titration/titreset.htm http://www.br.cc.va.us/turner/Chm111/reading_the_buret_and_titration%20technique_.htm ...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 Classifying Materials section.

Found what you're looking for?

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

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 Classifying Materials essays

  1. Determine the formula of the hydrate in hydrated copper (II) sulfate empirically, i.e. to ...

    0.002g Mass of Crucible and CuSO4 � xH2O after heating: 9.291g ? 0.002g Calculation of Key Values Mass of CuSO4 � xH2O: m(CuSO4 � xH2O) = m(Crucible and CuSO4 � xH2O) - m(Crucible) = 10.058 - 8.024 m(CuSO4 � xH2O)

  2. An Investigation Into How the Mass of Zinc Effects the Heat Change In the ...

    aswell as the beaker * Using a more accurate measuring cylinder to measure the 25cm� of copper sulphate solution. * Cleaning the polystyrene cup more thoroughly after each experiment in order to remove any impurities I think that my results are accurate as the majority of the results are close

  1. An investigation into the water of crystallisation present in Hydrated Magnesium Sulphate

    scales are re-calibrated to 0.000 or as near to as possible in order to ensure there are minimal errors in the experimental stage. A crucial part of the experiment is to ensure that the mass crystallising dish and substance is measured a sufficient amount of times to ensure that all

  2. Investigation to Identify the Formula of Hydrated Copper Sulphate and in doing so Find ...

    * Ensure to control Bunsen flame to avoid blackening pipe clay triangle or crucible. * Weigh after reaction then heat again and re-weigh to make sure reaction has finished. * Wear Goggles at all times during practical. Scientific Knowledge: * I have chosen the method I have as compounds with

  1. Investigating the Factors Affecting the Temperature Change Between Zinc and Copper Sulphate

    in powdered form, than if it is in pieces that have to be cut up. During the experiment the rate of reaction will be much quicker if I use powdered zinc because it will have a much larger surface area than pieces of zinc and so, would dissolve faster.

  2. The role of mass customization and postponement in global logistics

    In the wake of growing competition, even government controlled firms have started to practice customisation in limited ways. Cooptex, the Cooperative textile firm of Tamil Nadu, Government has introduced recently the free selection of design, pattern etc. for the silk and cotton sarees by the consumers through computers which can be produced and delivered in a definite period.

  1. Investigate a factor that effects the change in temperature between iron and copper sulphate.

    + 10 + (5 x 16) 56 +32 +(16 x 4) Molecular 56 + (96 +64) + (10 + 80) 88 + 64 Mass: 56 + 160 + 90 152 56 + 250 152 56g of Fe.....reacts with.....1Litre CuSO4 5.6g of Fe.....reacts with.....100ml of CuSO4 0.56g of Fe...reacts with...10ml of CuSO4 Therefore, if I were to

  2. Decomposition of copper carbonate - proving one of two equations.

    Copper (II) compounds are by far the most common - they are called "cupric". Copper (I) compounds - "cuprous" compounds are far less common. Copper atoms most readily go to oxidation state +2, by a variety of reactions. Cupric compounds are unstable in the presence of water, so must either be insoluble or form complexes with other molecules.

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