• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4

# A2 Chemistry -Assessed Practical In theory the remaining mass after the heating will be only FeSO4, so from this the mass that was evaporated off would be entirely water. From this we can calculate

Extracts from this document...

Introduction

A2 Chemistry - Assessed Practical Method 1 Mass (g) Total Mass Loss (g) Original Mass 1.44 0.00 Measurement 1 1.05 0.39 Measurement 2 0.90 0.54 Measurement 3 0.88 0.56 Measurement 4 0.86 0.58 Measurement 5 0.86 0.58 Calculations In theory the remaining mass after the heating will be only FeSO4, so from this the mass that was evaporated off would be entirely water. From this we can calculate: The number of moles of H2O is the n= m/Mr H=1 O=16 H2O = 18 =Mr 0.58/18 = 0.032 moles of H2O The remaining mass should be entirely FeSO4 so: Fe=56 S=32 O=16 56 + 32 + (4x16) = 152 = Mr The number of moles of FeSO4 = 0.86/152 = 5.657894737 x 10^-3 Moles To find the ratio of H2O we need to use: 0.032/5.657894737 x 10^-3 = 5.655813953 This is approximately 6 so the Formula of the Hydrated Iron (II) ...read more.

Middle

Using Mr = n/m 3.08 / 0.01103125 = 279.2067989 Then take away the Mr of FeSO4 gives the amount of water in the compound 279.2067989 - 152 = 127.2067989 Then divide by the Mr of water to get how many are in the original compound 127.2067989 / 18 = 7.067044381 So the formula of the compound is FeSO4.7H2O Evaluation Measurement Errors One of the largest measurement errors is in the weighing of the compound. The scales used only weigh to 2 decimal places. For a titration this is not accurate enough as the titration can precise. The preferable accuracy would be to at least 3 decimal places as the lack of accuracy could greatly affect the results of the calculations. Also in Method 1 we do not know whether or not there was any absorption of moisture during the cooling period. This can be a large problem as the method relies on the fact that the reaction no longer takes place when there is no more water. ...read more.

Conclusion

This may still be inaccurate as the steam given off will also be trapped within the burette. To avoid this it could travel through a condenser first in order to extract the steam from other products. With this the total mass of the compound could be found and calculations could be accurate enough to calculate the amount of H2O in the formula. There is also a problem in not knowing when the reaction is finished except by measuring the compound every so often to find when the mass no longer changes. A more accurate set of scales would help with this problem as we could check for when the mass of the compound stops changing by such large amounts, so that we could assume it was the compound that was now thermally decomposing. These errors are mainly to do with Method 1 and so I would again recommend Method 2 as there are far fewer inaccuracies and procedural errors. The only problem factor in Method 2 is human and unpredictable. ?? ?? ?? ?? Jonathon Higham ...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 Aqueous Chemistry 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

# Related GCSE Aqueous Chemistry essays

1. ## The aim of this practical experiment is to calculate the formula of hydrated Iron(II) ...

The following are some of them. - Temperature: we had to wait for the crucible and the contents to cool before measuring other wise, the water was still evaporating whilst hot, until after two minutes when the water had stopped evaporating every time we did the experiment.

2. ## Synthesis of Iron (II) Sulphate FeSO4

Take to crystals out and put in the sealed plastic bag. D. Results Some shiny light-green crystals of Iron (II) Sulphate (FeSO4) are obtained along with some small brown particles and dust. Total weight of crystals of Iron (II)

1. ## Collision Theory

When the reaction finishes, the black X we have placed on an A4 sheet of paper will disappear. We will measure the time taken for the solution to become fully cloudy with a stop clock. We will perform this experiment a number of times and each time change the concentration

2. ## Organic compound identification.

A normal individual roughly excretes between 28 and 30g of D per day. The following information was given to help find the Mr and MF of D. Compound D can be completely hydrolysed in the presence of a suitable enzyme. One mole of water will hydrolyse one mole of D.

1. ## SCIENTIFIC PRACTICAL TECHNIQUES

pH4, pH7 and pH10 in the beakers. The buffer was connected to the pH meter. Calibrating the pH meter. Measuring the solutions. Washing the buffer every time of use. pH paper was used to get a range of pH solutions. Taking results down from the pH meter.

2. ## How much Iron (II) in 100 grams of Spinach Oleracea?

Experiment A - preformed using a spinach extract solution created by boiling 15 grams of spinach in Sulphuric acid (aq) and making it up to a 100cm3 solution by adding Sulphuric Acid (aq). [Potassium Manganate (VII) (aq)] = 0.01 mol dm-3 20 cm3 of Spinach extract solution mixed with 50cm3 Sulphuric Acid (aq)

1. ## Assessed Practical: Titration

this is where the best view of the meniscus is, and from different angles the water can look different. A rough titration was carried out to see how much of the sulphuric (VI) acid was roughly needed to react with the hydrous sodium carbonate.

2. ## copper practical

Electrolysis allows you to gain a higher percentage of pure copper as opposed to having impure copper. When aqueous copper sulphate solute is electrolysed on copper electrodes, the copper is deposited on the cathode (which contains pure copper) and the anode loses weight (the anode has the impure copper on it).

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