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

Acid-Base titration by double indicator method

Extracts from this document...

Introduction

Date: 01/12/2010 Objective To determine the proportions of sodium carbonate and sodium hydroxide in a mixture solution using double indicator method. Procedures 1. 25 cm3 of the mixture solution was pipetted into a conical flask. 2. Two drops of phenolphthalein indicator were added into the conical flask. 3. The mixture solution was titrated with the given standard hydrochloric acid(0.098M). 4. The mixture was titrated to the end-point. 5. At the end point, the pink colour of phenolphthalein indicator was just discharged. 6. The burette reading (x) was recorded. 7. Two drops of methyl orange and a further quantity of acid were added 8. The mixture was titrated to the end-point. ...read more.

Middle

/ cm3 12.30 12.30 12.20 12.40 Mean value of x= (12.30+12.20+12.40)/3 =12.30 cm3 y Trial 1 2 3 Final burette reading / cm3 19.50 38.80 36.60 19.80 Initial burette reading / cm3 12.40 31.80 29.40 12.70 Volume of acid used(x) / cm3 7.10 7.00 7.20 7.10 Mean value of y= (7.00+7.20+7.10)/3 =7.10 cm3 Questions: 1. Volume of hydrochloric acid required for the complete neutralization of sodium carbonate in 25 cm3 of solution =2y =2 x 7.10 =14.20 cm3 No. of mole of hydrochloric acid required= (14.20/1000)(0.098) =0.0013916mol. By Na2CO3 + 2HCl --> 2NaCl +H2O +CO2 ?No. of mole of hydrochloric acid required =2( No. of mole of sodium carbonate in 25 cm3 of solution) ...read more.

Conclusion

?The concentration of sodium carbonate in the solution in gdm-3 =[0.0005096x(22.99+ 16.00+ 1.008)]/(25/1000) =0.815319232 ~0.82 gdm-3 ?The proportions of mass of sodium carbonate to sodium hydroxide in the mixture solution =(2.94991368 x 25/1000)/(0.815319232 x 25/1000) =1 : 0.276387488 ~ 1 : 0.276 ?The proportions of number of mole of sodium carbonate to sodium hydroxide in the mixture solution =0.0006958/0.0005096 =1 : 0.732394366 ~1 : 0.732 Conclusion The proportions of mass of sodium carbonate to sodium hydroxide in the mixture solution was 1 : 0.276 while that of number of mole of sodium carbonate to sodium hydroxide was 1 : 0.732 Reference Yahoo!Mini http://www.titrations.info/ http://en.wikipedia.org/wiki/Titration http://hk.knowledge.yahoo.com/question/question?qid=7010032200973 http://www.creative-chemistry.org.uk/alevel/module1/documents/N-ch1-49.pdf HKCEE Chemistry Notes Section IV by Ms Sin W L F.6 Chemistry Notes Section I by Ms Sin W L The End ?? ?? ?? ?? F.6 Chemistry/TAS 8/P.1(3) ...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

Here's what a star student thought of this essay

4 star(s)

Response to the question

Initially, the candidate should expand on the objectives to include their predictions. It is also recommended to put some of the known theory before the method to help agree with your predictions. The method and results sections are excellent. A ...

Read full review

Response to the question

Initially, the candidate should expand on the objectives to include their predictions. It is also recommended to put some of the known theory before the method to help agree with your predictions. The method and results sections are excellent. A diagram could have aided the method but wasn't essential.

Level of analysis

The analysis in the questions is generally good but explaining what is being calculated would have been helpful. If the student had made a hypothesis initially, it would have been possible to compare this with the final result and make a better conclusion, looking at the reliability and accuracy of the results. The references are good but should be shown where they have used through the text.

Quality of writing

Spelling, punctuation and grammar is very good. Technical terms are used appropriately. Overall a good piece of work.


Did you find this review helpful? Join our team of reviewers and help other students learn

Reviewed by k9markiii 23/03/2012

Read less
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. Marked by a teacher

    Heat of Neutralization. Objective: To investigate the ...

    5 star(s)

    The maximum temperature that was reached after the time of mixing would be recorded to be the solution's final temperature. Start monitoring the temperature as soon as the solutions had been mixed. Procedures: The experiment was worked in pairs and I was grouped with Peter Chan, and the acid and

  2. Determination of the Amounts of Sodium Hydroxide Solution and Sodium Carbonate in a Mixed ...

    17.2 cm3 (13.9 cm3) 17.2 cm3 (14.7 cm3) 13.7 cm3 (13.6 cm3) 15.4 cm3 (13.9 cm3) 17.5 cm3 (14 cm3) Reading when color changes from yellow to orange ( Volume of HCl used) 22.5 cm3 (5.3 cm3) 21.5 cm3 (4.3 cm3)

  1. Determination of isoelectric point of protein (casein).

    charge expressed by the basic amino group of the amino acid is equal to the charge expressed by the acidic carboxyl group. Once the protein becomes dipolar, the overall electrostatic charge becomes zero. The protein becomes hydrophilic and insoluble in water because water can only dissolve molecules that are polarised.

  2. Preparation of Standard solution and Standardization of Hydrochloric acid

    Thus, the temperature of solution in conical flask drops. Thus, the end point of acid-alkali titration can be accurately detected by the temperature sensor connecting to the data logger. 5. Discuss the sources error of this experiment There are many sources of errors in this experiment. First of all, chemists may misjudge the color of the indicator(e.g.

  1. Acid-base titration. Objective To determine the concentration of sulphuric acid (H2SO4) using sodium ...

    Choice of Standard solution: In the experiment, we chose to use anhydrous sodium carbonate as the primary standard because it is (1) available in a pure form, (2) readily soluble, (3) not volatile---if it was as NaOH, then losses would occur during the weighing out of the substance, (4)

  2. Determination of Calcium Carbonate in Eggshells by Acid/Base Titration

    the American bald eagle). One method of monitoring the strength of the egg is by determining the percent calcium carbonate in the eggshell.1 The percentages calculated from the experiment will be compared against a reported value of 95% CaCO3 in a dry eggshell.2 MATERIALS and PROCEDURE Please refer to handout sheet.

  1. Objective: The purpose of this experiment is to determine the composition of a mixture ...

    Discussion The mean titre with the use of phenophthalein indicator is 24.98 cm3 while the mean titre with the use of methyl orange indicator is 9.90 cm3 and the mixture contains approximately 64% Na2CO3 and 36% NaOH. There are some sources of errors: (1) Inconsistent reading of the burettes (2)

  2. How are standard solutions prepared & how is titration carried out in industry

    As the light is been used as the principal of analysis, it is important to select an appropriate wavelength for analysis, as all the components in a titration absorb light. They try their best to select a wavelength which can absorbed by only one component, the part of the molecule

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