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

Chemistry: Strong Acid and Weak Base Titration Lab

Extracts from this document...


Chemistry: Strong Acid and Weak Base Titration Lab Cherno Okafor Mr. Huang SCH4U7 November 21st, 2012 Data Collection and Processing Concentration of the standard HCl solution: 0.1 M Data Collection: Trial 1 Trial 2 Trial 3 Final HCl Buret Reading ± 0.05 mL 38.3 45 54.5 Initial HCl Buret Reading ± 0.05 mL 29.9 38.3 45 Volume of NaHCO3 used ± 0.1 mL 9.2 9.5 9.8 Qualitative Data: I used the methyl orange indicator which was suitable for my titration because of its clear and distinct colour change from orange to a bright red at the endpoint At the beginning of the titration after I added 3 drops of methyl orange into the base (NaHCO3) and swirled, I began titrating the acid (HCl) slowly, and initially in the methyl orange and base, there was a tiny amount of red colour present, but then it quickly disappeared due to insufficient HCl (H+ ions)ï then I gradually kept titrating more acid while swirling and there was even more red colour present, until finally I reached the endpoint when the orange-yellow colour had completely transformed into a red colour Changes from an orange-yellow colour (slightly higher pH 4.4) to a bright red colour (at low pH 3.1) at the endpoint and point of equivalence Baking Soda (NaHCO3) absorbed the odour caused by the strong acid of HCl when I mixed the two: bleach-like smell Processing If the concentration of an acid or base is expressed in molarity, then the volume of the solution multiplied by its concentration is equal to the moles of the acid or base. ...read more.


Cb = (0.9 ± 1.6%) / (9.5 ± 1.05%) Cb = 0.0947 ± 2.65% ï 0.0947 ± 0.00251M is the concentration of the base for trial 2 Theoretical Base Concentration = 0.1 ± 0.0005 M Experimental Base Concentration = 0.0947 ± 0.00251 M Trial 3 Calculation: First find change of volume of the acid used up in the titration: Va = Vfinal – Vinitial Va = 54.5 ± 0.05 – 45 ± 0.05 Va = 9.5 ± 0.1 mL Therefore, nVb x Cb = Va x Ca (1)(9.8 ± 0.1)(Cb) = (9.5 ± 0.1) (0.1 ± 0.0005) Cb = (9.5 ± 0.1) (0.1 ± 0.0005) / (9.8 ± 0.1) Cb = (9.5 ± 1.05%) (0.1 ± 0.5%) / (9.8 ± 1.02%) Cb = (0.95 ± 1.55%) / (9.8 ± 1.02%) Cb = 0.0969 ± 2.57% ï 0.0969 ± 0.00250M is the concentration of the base for trial 3 Theoretical Base Concentration = 0.1 ± 0.0005 M Experimental Base Concentration = 0.0969 ± 0.00250 M Now, I will average all 3 trials: Trial 1: 0.0913 ± 2.78% ï 2.78% / 100% x 0.0913 = 0.0913 ± 0.00254 M Trial 2: 0.0947 ± 2.65% ï 2.65% / 100% x 0.0947 = 0.0947 ± 0.00251 M Trial 3: 0.0969 ± 2.57% ï 2.57% / 100% x 0.0969 = 0.0969 ± 0.00250 M Therefore: (0.0913 + 0.0947 + 0.0969) ...read more.


Perhaps drying it could have made a difference instead of leaving it wet. Maybe some of the neutralized solution was left behind after I washed out the flask, and it mixed with the tiny water droplets also left behind in the flask. Before I started the next trial, it could have interfered with that titration and provide inaccuracy. Another error to mention is getting the exact endpoint during the titration. The indicator could have ranged from different shades of red (starting with orange) but I assumed that the moment it turned a standard red colour, it was finished. In addition, I could mention that I may not have properly swirled the solutions before beginning the titration process to make sure nothing (residue) settles at the bottom. This could have impacted the inaccurate colour change of the indicator in the neutralization and hence unknown standard colour. I also kept on adding drops when the solution was already a red colour towards the end. However, this may have either darkened or lightened the colour too much in an effort to change the precision of the indicator colour at the equivalence point or end point. Finally, at some moments, I was in a hurry to finish titrating, and so I may have flushed out the acid in large amounts. I realize that near the neutralization point, the acid must be released in drops. However, for the third trial, I did sort of flush out a large amount of the acid and therefore could have missed the neutralization point which could cause errors in results. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate 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 International Baccalaureate Chemistry essays

  1. Oxalic Acid Titration Lab

    Hence, the average volume of the oxalic acid solution required for the neutralization of sodium hydroxide is 26.9cm3 Knowing the number of moles of the acid and the average volume of the acid titrated, the concentration of the acidic solution was calculated.

  2. acid base lab report

    = 1.999g NaOH . Part II: Observations Table 4: Observations of colour changes of Acid-Base indicators during Titration. Initial colour (before change)End point colourpH at End Point (colour change) Titration of HCl with NaOHclearPinky-red10.1 Titration of CH3COOH with NaOHredyellow6.0 Titration of NH3 with HCl Pinkyclear8.9 Discussion The determination of the

  1. Preparation of ear drops practical. Titration of NaHCO3

    x Molarity Molarity= 0.1 x 30.6/5.005 = 0.61 Calculation of the number of grams of NaHCO3 in 100ml of prepared eardrops. In this experiment 5.005 grams of NaHCO3 was measured. To ensure that this is the correct amount used the molar mass of NaHCO3 is calculated and then multiplied by

  2. Free essay

    pH titration curves Lab Report. How does the use of a strong acid with ...

    The data tables include the volume added of base solution to acidic solution each time (mL) for each trial of the experiment, the different neutralization points for each part of the experiment.

  1. Free essay

    Titration of a weak acid with a strong base

    pH and volume readings were noted down, as shown in the table below. A titration curve was then plotted. pH (weak acid) Volume in ml (NaOH) �1 pH (weak acid) Volume in ml (NaOH) �1 1.98 0 11.12 18.8 2.45 2 11.35 19 2.63 3 11.51 19.2 2.78 4

  2. Thermometric titration lab

    +26.8)�2 26.8 � 0.1 8.0 � 0.1cm3 80 � 0.5s (26.6 +27.0)�2 26.8 � 0.1 10. 0 � 0.1cm3 100 � 0.5s (26.5 +26.9)�2 26.7 � 0.1 12.0 � 0.1cm3 120 � 0.5s (26.4 +26.8)�2 26.6 � 0.1 14.0 � 0.1cm3 140 � 0.5s (26.1 +26.7)�2 26.4 � 0.1 16.0

  1. Which fruit juice (Orange, Apple, Peach, Pineapple, and Apricot) has the highest concentration of ...

    Uncertainties should be taken into consideration because of the meniscus; we may not see 0.05 mL of difference. CONCLUSION: The task of this experiment was to find the concentration of ascorbic acid in different fruit juices by using an indicator called DCPIP in a titration reaction.

  2. Chemistry Titration Acid Base Lab

    However, when the base is added and the endpoint has been reached, the color changes to a dark blue shade. If over titration occurs, the solution will remain blue. 21.20 21.60 0.4 21.60 22.00 0.4 Data Processing Table B: A Representation of the Volume of Sodium Hydroxide that was Required

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