It is highly beneficial to be able to calculate the concentration of a saturated solution. Indeed, knowledge of the concentration is required to calculate solute solubility and if precipitates will form when the solution is mixed with other reagents. This has many applications in industrial processes. For these reasons, this experiments aims to determine the concentration of a saturated barium hydroxide (Ba(OH)2) solution by conductometric titration and gravimetric analysis. Conductometric titration involve examining the change in Ba(OH)2 (aq) conductivity as sulphuric acid is added. Conductivity initially has a high reading due to the presence of ions in solution and then reaches a minimum at the reaction endpoint, due to complete neutralisation …show more content…
The mixture was then cooled. Vacuum filtration was then performed on the mixture. This was done by carefully rinsing the precipitate mixture over moist, pre-weighed filter paper into a Büchner flask under vacuum. The residue was then moistened with ethanol while the flask was still under vacuum. The residue and filter paper were placed on a pre-weighed watch glass and weighed. They were then placed in a drying oven for about fifteen minutes and then reweighed. They were reweighed after a further five minutes in the oven and then again after another five minutes, so as to ensure the precipitate had been fully dried. Results from both the conductometric titration and gravimetric analysis were compared with other groups and mean values were established. The experiment achieved its purpose in that the concentration of Ba(OH)2 solution was determined. According to the conductometric titration, the concentration of Ba(OH)2 (aq) was 0.196 M. Calculations based on gravimetric analysis revealed a concentration of 0.0669 M. Evidently, there is a high degree of imprecision between the values determined by each technique. It appears however that the gravimetric analysis was more accurate. The standard deviation for BaSO4 mass was 0.035 and …show more content…
According to the conductometric titration, the concentration of Ba(OH)2 (aq) was 0.196 M. Calculations based on gravimetric analysis revealed a concentration of 0.0669 M. Evidently, there is a high degree of imprecision between the values determined by each technique. It appears however that the gravimetric analysis was more accurate. The standard deviation for BaSO4 mass was 0.035 and the confidence interval was ±0.0256 g. This illustrates that there is 90% certainty that the actual mass of the BaSO4 precipitate was within 0.0256 g of the calculated mean (0.156 g). It should be noted that an outlier (1.45 g precipitate) was removed from the gravimetric analysis calculations due to being 9.29 times greater than the average. The standard deviation for end point volume – the basis of calculations for the conductometric titration – was 6.616. The confidence interval was ±5.443 mL. The much larger confidence interval for end point volume illustrates a higher degree of uncertainty regarding the precision of this measurement. For this reason, it appears that gravimetric analyses are more suitable for determining saturated solution concentration. This has importance in research where the solubility product (Ksp) needs to be determined or when predictions need to made regarding whether a precipitate will form. One of the principle reasons why conductometric titration
For part C, the concentration of was determined to be 1.01 mol/L, 0.973 mol/L, and 1.158 mol/L. These results show a relatively closed to the accepted 1.00mol/L of NaOH. The differences of these results are understandable since the concentration of NaOH would changes over time because during the transfer of NaOH powder in part A, it was exposed to the air, thus it could reacts with CO2 in the atmosphere to produce Na2CO3 and water, therefore, changing the concentration of NaOH. Furthermore, the NaOH could also react with the glass thus it wills also reducing its concentration. However, all of the concentration of NaOH that was determine are maximum of 0.158mol/L differences compare to the standard 1.00 mol/L, therefore, it can be concluded that the result are accurate.
This can be done by first finding the products of the chemical reactions, which are found by swapping the anions on each reactant. Once this is done, predictions can be made. The table above, describes the solubility rules, these are used to decide whether a compound will be soluble, and then consequently to this reveal a precipitate. Barium sulfate for example is insoluble and if it was to be mixed with an aqueous compound, barium sulfate would be the precipitate. This is an example of how a prediction can be made, without physically viewing the experiment or given the results. It is also a way of identifying what the precipitate is once the experiment has been
Bibliography "Sodium Bicarbonate" American Heritage Dictionary and Electronic Thesaurus (1985) 21: 347 "Acids and Bases" Science Activities Winter 95, Vol. 31 issue 4, p28. McCarthy, E. Jerome Basic Chemistry Homewood Illinois: Irwin-Dorsey, 1968.
Then, the weak acid was isolated from the NaOH extract. After cooling the mixture, HCl was pipetted into the flask, neutralizing the NaOH. This enabled the, now precipitated, weak acid to be filtered out of the solution. After vacuum filtration was used to remove the solid acid, percent recovery was recorded, and the weak acid was moved to a
Solubility is defined as the maximum amount of a substance that will dissolve in a given amount of another substance at constant temperature and pressure. Solubility is typically expressed in terms of maximum volume or mass of the solute that dissolve in a given volume or mass of a solvent. Traditionally the equilibrium solubility at a given pH and temperature is determined by the shake flask method. According to this method the compound is added in surplus to a certain medium and shaken at a predetermined time. The saturation is confirmed by observation of the presence of un-dissolved material. Saturation can also be reached if the solvent and excess solute is heated and then allowed to cool to the given temperature. After filtration of the
Solid A was identified to be sodium chloride, solid B was identified to be sucrose, and Solid C was identified to be corn starch. Within the Information Chart – Mystery White Solid Lab there are results that distinguishes itself from the other 4 experimental results within each test. Such as: the high conductivity and high melting point of sodium chloride, and the iodine reaction of corn starch. Solid A is an ionic compound due to its high melting point and high electrical conductivity (7), within the Information Chart – Mystery White Solid Lab there is only one ionic compound which is sodium chloride, with the test results of Solid A, it can be concluded that is a sodium chloride. Solid B was identified as sucrose due to its low electrical
The solutions were then stirred with separate stirring rods to mix the NaCl solution and the deionised water into a homogeneous solution.
The mixture was poured through a weight filter paper and Sucrose washed with a 5ml of dichloromethane. The resulting solid was left in a breaker to dry for one week, to be measured. Left it in the drawer to dry out for a week and weighted it to find the sucrose amount recovered amount.
For this experiment we have to use physical methods to separate the reaction mixture from the liquid. The physical methods that were used are filtration and evaporation. Filtration is the separation of a solid from a liquid by passing the liquid through a porous material, such as filter paper. Evaporation is when you place the residue and the damp filter paper into a drying oven to draw moisture from it by heating it and leaving only the dry solid portion behind (Lab Guide pg. 33.).
The materials for this experiment include Magnesium, a Bunsen burner, a analytical balance, and an evaporation disk. Beginning the experiment the empty evaporating dish is placed on the analytical balance and the mass is recorded. Then, Magnesium is placed in the evaporating dish and put back on the analytical balance and the
When benzoic acid paired with 1.0 M NaOH, it was observed that both compounds were soluble. Upon the addition of 6.0 M HCl into this solution, benzoic acid became insoluble. Benzoic acid was also insoluble in 1.0 M HCl. Ethyl 4-aminobenzoate was found to be insoluble in 1.0 M NaOH and soluble in 1.0 M HCl. But then, after adding 6.0 M NaOH into the test tube C (mixture of ethyl 4-aminobenzoate and 1.0 M HCl), a white powdery solid (undissolved compound) was formed. These demonstrate that both the acid and base became more soluble when they were ionized and less soluble when they were
Gusdinar T. COMPLEXOMETRIC TITRATION An application method of Inorganic Pharmaceutical Analysis [homepage on the internet] . No date. [cited 2014 Mar 20]. Available from: http://download.fa.itb.ac.id/filenya/Handout%20Kuliah/Inorganic%20Pharmaceutical%20Analysis%202008/English%20Version/05.%20COMPLEXOMETRIC%20TITRATION.pdf.
Electrolysis Investigation Planning In this investigation, I will assess how changing the electric current in the electrolysis of acidified water affects the rate at which hydrogen gas is produced. The solution to be electrolysed is made up using acid and water. It is of little consequence what acid is used however in this case I will use Sulphuric acid (H2SO4). When H2SO4 is put in water it is dissociated and forms ions: H2SO4 → 2H (2+) + SO4 (2-) Ions are also present from the water in the solution: H2O → H (+) + OH (-) During the electrolysis process, the positive hydrogen ions move towards the cathode and the negative hydroxide and sulphate ions move towards the anode.
From the results gathered and the graphs drawn it is evident that the concentration of sodium thiosulfate is inversely proportional to the time take for the cross to disappear. Despite random and systematic errors being present, a trend can still be seen within the data. The experiment could be improved with changes to the procedure and apparatus.
Titration is a technological process in which a solution, known as a titrant, is slowly and carefully added from a burrette into a fixed volume of another solution (known as the sample). In an acid-base titration an acid neutralizes a base or vice versa. This process is maintained untill the reaction between the titrant and the sample (acid and the base) is judged to be complete. The reaction is judged to be complete when the endpoint is reached. An endpoint in a titration analysis is referred to as the point at which no more titrant is added due to an observable colour change of an indicator. Indicators can be used to find an endpoint because they change colour when the pH of a solution changes and an endpoint in a titration is an empirical approximation of the equivalence point, which is the point of major pH change in the titration sample due to the fact that equal chemical amounts of reactants have been combined at that point. All indicators have a pH range, which is the range of pH values at which the colour of the indicator changes. Thus