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

Determination of acid concentration in gastric juice

Extracts from this document...

Introduction

Determination Of The Concentration Of Acid In Gastric Juice Introduction: In this experiment, I will be able to carry out a technique known as titration. The experimental titration is used to find out how accurately how much a chemical substance is dissolved in a given volume of a solution, that is the concentration of the solution. The aim of this particular experiment is to revise the use of pipettes and burettes and titrations by the determination of the concentration of hydrochloric acid in an unknown solution and also reinforce the concept of molarity hence I will be using the method titration. This particular method is suitable for our aim because it will allow us to obtain results which enables us to determine the molarity of a solution of sodium hydroxide against our two separate standards. The equation I will be looking at is: NaOH(aq) + HCl(aq) � NaCl(aq) + H2O(l) Acid Base Salt Water The reaction is an acid-base reaction which involves the transfer of protons. Acid-base reactions are also known as neutralisation reacrions. The compound formed by the cation of the base and the anion of the salt. When using the indicator, phenolphthalein, the colour will change to light pink. ...read more.

Middle

* Note down your results. * Repeat the experiment 3 times * In order to get concordant results, results should be within +0.01 of each other. * Repeat the experiment using gastric juice as your standard instead of HCl. Results Results showing the titration of sodium hydroxide solution with 25cm3 0.01mol dm-3 HCl: Initial burette reading(cm3) Final burette reading (cm3) Volume Used(cm3) Rough titration (HCl) 0.00 cm3 25.7cm3 25.7cm3 First Accurate Titration 0.00 cm3 25.6cm3 25.6cm3 Second Accurate Titration 0.00 cm3 25.5cm3 25.5cm3 Third accurate Titration (If needed) N/A N/A N/A Average Volume of Sodium Hydroxide solution used= 25.60cm3 Number of moles of NaOH present in this volume = 2.56 x 10cm-4 25.6/1000 =25.6/1000 Therefore: molar concentration of NaOH= 0.01 Results showing the titration of sodium hydroxide solution with 25cm3 0.01mol dm-3 Gastric Juice: Initial burette reading(cm3) Final burette reading (cm3) Volume Used(cm3) Rough titration (Gastric Juice) 0.00 cm3 30.7 cm3 30.7 cm3 First Accurate Titration 0.00 cm3 31.5 cm3 31.5 cm3 Second Accurate Titration 0.00 cm3 30.8 cm3 30.8 cm3 Third accurate Titration (If needed) 18.1 cm3 49.0 cm3 30.9 cm3 Average Volume of Sodium Hydroxide solution used= 30.8cm3 Number of moles of NaOH present in this volume: =3.08x10-4 30.8/1000 =30.8 x 10-4 Therefore number of moles of HCl in 25cm3 of gastric Juice= 3.08 x ...read more.

Conclusion

In order to make this more accurate, I could use longer and thinner burettes which will allow me to obtain a much more accurate reading. Also the pH of gastric juice differed. In order to overcome this, we could measure the gastric juice beforehand instead of after the experiment. We could also measure it before each titration. In my experiment, I tried to minimise error wherever I could and also make my experiment reliable. I tried to make sure, in order to minimise any possible additional errors to wash out all of my equipment by washing it with distilled water to avoid any contamination. All of my experiment I would say is reliable as they can be repeated and tested again. Conclusion In conclusion, my results were accurate and reliable to the best of my ability; however with using more precise equipment and having a longer to do it may have increased the accuracy. Also with aids of a colour wheel in order to obtain the same shade of pink may help. The aims of this experiment were met was we managed to work of the molarity of our two substances by using the titration method. Overall I think that the titration experiments for both the HCL and the gastric juice were successful. Referencing http://www.bsieducation.org/Education/14-19/topic-areas/applied-science/images/titration-equipment.jpg ?? ?? ?? ?? 1 ...read more.

The above preview is unformatted text

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

  1. Hydrolysis of Salts and choice of Indicators / Titration Curve

    2. On what previously obtained EXPERIMENTAL evidence do base your above answer? NCl (aq) is not expected to be neutral but weak acid. This is because the Ammonium ion is Bronstead-Lowry acidic: it can donate to give a neutral NH3 molecule.

  2. Werner Complexes - Preparation and Determination of Structural Formula

    In the example shown in the results section, 4.44*10-4mol of silver nitrate was used to react with 1.99*10-4mol of pentaamminechlorocobalt(III) chloride. Since the ratio was nearly 2:1 silver nitrate to pentaamminechlorocobalt(III) chloride, this concludes that two moles of non bonded chlorine are present per one mole of pentaamminechlorocobalt(III)

  1. A 0.60 um film of silicon dioxide is to be etched with a buffered ...

    The diagram focusses on the amount that the window edges have expanded during the etching processes. The variable drun has been introduced in the above diagram to denote the horizontal component of the slope. The variable drun has been introduced in the above diagram to denote the vertical component of the slope.

  2. Forensic Chemistry - Ion Selective Electrode. The objective of experiment is to determine ...

    In many cases the composition of these solutions are carefully guarded ‘trade secrets’ and the reagents are simply labelled as e.g. "TISAB for nitrate electrode". 6.4 Reproducibility Sensitivity (Slope factor) We notice from the Nerstian equation the slope factor at 298K (25°C)

  1. The aims of this experiment are to measure the heat of decomposition of hydrogen ...

    = 62.805 J Where heat lost to calorimeter = (Tmax ? T1) x c Thus heat capacity of calorimeter, c = 8.374 J/OC To calculate qsol and qcalorimeter: Heat change for solution, qsol = -specific heat of solution x mass of solution x (Tf - Ti)

  2. The objective of this experiment is to determine how a buffer system resists large ...

    being to be steeper and steeper and eventually the gradient become nearly vertical(exhaustion of conjugate acid or base). Moreover, we notice that greater volume (almost twice) of hydrochloric acid has to be added to Buffer A to achieve the similar gradient (steepness)

  1. Experiment - determination of the valency of magnesium

    moles of magnesium: number of mole of hydrogen gas 1.413x10-3 mol : 1.541x10-3 mol 1 : 1 Thus, X/2 = 1 X = 2 ________________ Discussion: Stoichiometry is the branch of chemistry and chemical engineering that deals with the quantities of substances that enter into, and are produced by, chemical reactions.

  2. EXPERIMENTAL DESIGN: Measurement of Density and Determination of Partial Molar Volume, and the Effects ...

    The partial molar volume is not necessarily the same as the volume of one mole of the pure component. The volume of a solution is dependent on its temperature and pressure and the amount of each component used to form the mixture.

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