• 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
5. 5
5
6. 6
6
7. 7
7

# Finding out how much acid there is in a solution.

Extracts from this document...

Introduction

Finding out how much acid there is in a solution. During the extraction of a metal from its ore sulphur dioxide is often produced. This is converted to sulphuric (VI) acid. I have a sample of this acid, which is thought to have a concentration between 0.05 and 0.15moldm-3 . I have been asked to find an accurate value for its concentration. To obtain this I will use titration. By neutralizing the acid with a base, sodium carbonate, of set concentration, in the presence of an indicator, I will be able to calculate the concentration of the acid. Planning Apparatus: * 100cm� conical flask * 10cm� pipette and filler * Burette * 50cm� beaker * Funnel * Clamp stand * Glass stirring rod * White tile Solutions: * 100cm� acid solution sulphuric (VI) acid * 5.3g solid anhydrous sodium carbonate * Methyl orange indicator Method Add 500cm� distilled water to 5.3g anhydrous sodium carbonate and stir until the solid has completely dissolved. This is now a solution of 0.1moldm-3 sodium carbonate (alkali). Add 50cm� sodium carbonate to the burette using the funnel, then remove the funnel. Fill the conical flask with 10cm� sulphuric acid using the pipette. Add 5 drops of methyl orange indicator. ...read more.

Middle

RFM = 2 x 23 + 12 + 3 x 16 = 106 Moles= = 0.0251 moles (3sf) Combined with 250cm� water = 0.25 dm�. Therefore concentration in moldm� = = 0.100moldm� (3sf) Concentration of acid solution: Equation of neutralisation of sulphuric acid with sodium carbonate: Which means that the mole ratio of sulphuric acid : sodium carbonate is 1:1 Amount of sodium carbonate needed to neutralise 25cm� sulphuric acid = 27.7cm� Moles in 27.7cm� of 0.100 moldm� solution = 0.0277 x 0.1 = 0.00277 moles . Ratio : = 1:1 therefore moles = 0.00277 0.00277 moles in 25cm�. Concentration of= = 0.111moldm� (3sf) Conclusion The results obtained from my titration suggest that the concentration of the acid is 0.111moldm�. Whilst this value may not be accurate, it appears to agree with the original statement that the acid 'is thought to have a concentration between 0.05 and 0.15moldm�'. This is strong evidence to suggest that the investigation results are quite satisfactory, as they are in the expected range. The accuracy of the results is discussed in the evaluation. Evaluation There were no anomalous results obtained. As four of the results were the same titre, and all of the accurate titres were within 0.5cm� of the rough titre. ...read more.

Conclusion

Proposed improvements to method This investigation could be made more accurate with the use of a pH meter, rather than using a pH indicator to see when neutralisation occurs. This would eliminate the most significant source of error in the investigation (calculated to be around 1.8%). It would indicate more clearly when neutralisation occurs - methyl orange indicator changes colour from red to yellow at around pH 3.5 - 4, but a pH probe would give the exact point of neutralisation. Although this would not make a large difference in terms of titre, as the solution changes very quickly from acid to alkali as it nears neutralisation point, it would make the investigation far more reliable and not subject to individual colour perception. In order to minimise measurement errors, larger quantities of all solutions could be used, although concentrations would remain the same. This would reduce all errors, for example: 250cm� graduated flask. Error = = 0.08% 1dm� graduated flask. Error = =0.02% However, I would only consider this if more complex equipment was not available and a great deal of accuracy was required, as it would be time-consuming and would require some non-standard laboratory equipment. This would not be a worthwhile improvement if a pH probe were available. Results Titration Rough 1 2 3 4 5 Final burette reading Initial burette reading Titre ...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. ## Enthalpy of Neutralisation.

3 star(s)

I choose these three substances because they vary in terms of their strength and were they are on the pH scale- this should give me a range of results, which test the accuracy of the pH scale. Hydrochloric acid has a pH of 1, while sodium hydroxide has a pH of 14.

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

Stopper the flask and invert it several times. This will make up a solution with the concentration of 0.09 mol dm-3. m. Repeat points j through to l varying the volume of 0.1 mol dm-3 Iron Ammonium Sulphate added to the volumetric flask to make up solutions at the

1. ## In order to find out the exact concentration of sulphuric acid, I will have ...

Water molecules can not form unless these molecules collide. Right at the end of the reaction the indicator should demonstrate neutralisation clearly, because on addition of an extra drop of basic solution the colour change should be instant. At this point 2 ions mat take longer to collide into each other in the solution.

2. ## To carry out a titration between a strong acid and a weak alkali, to ...

Risk Assessment: - * Wear safety glasses to prevent sulphuric acid and other chemicals splashing into your eyes. * Wear a lab coat as methyl orange stains and you need to protect your clothing in case other chemicals fall onto them.

1. ## Finding out how much acid there is in a solution.

Sodium carbonate, 2.65g * Digital scales * Distilled water * Beaker, 250cm * Dropping pipette * Glass rod * Volumetric flask, 250cm, with label * Filter funnel * Safety glasses * Using a watch glass on a scale weigh out accurately 2.65g of anhydrous sodium carbonate, using a spatula.

2. ## Find out how much acid there is in a solution

* I will be using a pipette filter and a 25ml pipette to remove the Sodium Carbonate solution from the volumetric flask. * I will carefully insert the pipette which will be attached at the bottom end of the pipette filter.

1. ## Find the accurate concentration of a solution of sulphuric acid acid of which concentration ...

1.33g Assuming the concentration of H2SO4 to be 0.15 moldm-3 , the concentation of Na2CO3 can be calculate as follows: Conc of H2SO4 (c) = 0.15 moldm-3 Volume of H2SO4 (v) = 25cm3 = 0.025dm3 Number of mole (n) = cv = 0.15 x 0.025 = 0.00375mols 0.025dm3 of Na2CO3

2. ## In this experiment I am finding out how much sulphuric acid is present in ...

Dilution is carried out by a factor of 10 exactly. A pipette is used to transfer 25.00ml of the solution to be diluted to a volumetric flask. The level of solution in the volumetric flask is brought nearly to the reference line by addition of water, the flask is stoppered

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