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

Who’s Cheating on the Vinegar?

Extracts from this document...


Who's Cheating on the Vinegar? Vinegar is an ethanoic acid. A wholesaler supplies chip shops. Design an investigation which identifies which chip shops are watering down the vinegar. Background Theory All acids contain the element "hydrogen". Water ionises the hydrogen to make it H+. To react all acids have to be ionised. Strong acids are almost completely ionised and weak acid are only partially ionised, which is why they don't react as much as strong acids. The pH of any acid would be below 7 (neutral), ranging from 1 (strong acid) to 6 (weak acid). Anything above 7 is an alkali, pH 14 being a strong alkali and pH 8 being a weak alkali. In titration we add alkali to the acid until the mixture neutralises. We use an indicator to tell us at which point the neutralisation occurs. ...read more.


by using the process of titration. Method o Measure 20cm� of sodium hydroxide using a pipette and a safety filler. Transfer the volume carefully into a conical flask. Then add a few drops of indicator (3 drops). o Fill your burette with acid down to the 0cm� mark on the burette. o Run acid (ethanoic acid) from your burette slowly until the neutralisation occurs o Write down the volume of acid you've used. o Repeat the method until you have at least two results which are very similar. Safety * Goggles * Chemicals harmful - acids * Do not run with chemicals. * Tie hair back * NaOH (sodium hydroxide) is an irritant. Apparatus o 20cm� pipette o 20cm� of sodium hydroxide (concentration = 0.5moles/dm�) ...read more.


(phenolphthalein) Results A B C D E Titration 1st reading 0.00 0.00 0.00 0.00 0.00 (cm�) 2nd reading 15.30 15.70 43.80 11.90 21.80 (cm�) volume of 15.30 15.70 43.80 11.90 21.80 acid used (cm�) Prediction I predict that the lower the volume needed to neutralise the acid, the more concentrated the acid is. Therefore the acid that shows the lowest volume result is the most concentrated. Evaluation In the experiment I used too much indicator for some of the acids (acids C & E). This made the results inaccurate, so I will only use 6 drops of indicator for acid I test. I didn't record enough values to get two accurate results, so next time I will test each acid at least 5 times so that my results can be more accurate and so that anomalous results are easier to spot. The rest of the experiment worked well so I don't plan to change anything else. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Physical 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

See related essaysSee related essays

Related AS and A Level Physical Chemistry essays

  1. Investigating the Rate of the Reaction between Bromide and Bromate Ions in Acid Solution

    Similarly for the phenol; since the experiment measures the amount of time for all the phenol to have reacted, if there was slightly too much phenol in the reacting mixture, the reaction could have taken longer to change colour, leading to an anomaly.

  2. Analysis of vinegar. Comparing the concentration of different samples of vinegar.

    near the opening and put on with applying too much pressure If broken, do not touch, clean up with dustpan and brush Running burette tap Overshoots Always ensure your turn the tap with the left hand and swirl with the right If overshoot occurs, repeat procedure Apparatus list: * 25cm3

  1. Investigating how concentration affects rate of reaction

    Gradient = -1.75 0.00024 = -7291.7 Gradient = -Ea = -7291.7 R R (the gas constant) = 8.31 J K-1 mol-1 The gradient equation can be rearranged as: -Ea = gradient x R = -7291.7 x 8.31 = -60594 Ea = 60594Jmoles-1 This can be converted to kJmoles-1 by dividing

  2. Neutralization investigation

    and negative ions, however within acids and alkalis the composition of hydrogen or hydroxide ions can give different strengths of acids and alkalis. When we refer to an acid as weak or strong we are referring to the amount of hydrogen ions concentrated within every mole of the substance when it is pure.

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