Decomposition of Aspirin Studied with UV/Visible Absorption Spectroscopy Aims: To determine the concentration of salicylic acid, formed from the hydrolysis of Aspirin, at regular intervals using the UV/Visible Absorption Spectroscopy From the concentration of salicylic acid, concentration of Aspirin to be determined using an equation Calculate the rate constant of this reaction and its order from a plot of graph of ln(aspirin) vs time Discuss the overall flaws and improvements to the experiment Results: As per schedule1, 0.212g of aspirin was added to 50 ml boiling water to form salicylic acid in a 100 ml flask, of which 1 ml was then pipetted to a 50 ml volumetric flask at the 5th min. Following an ice bath, the solution was mixed
The theoretical yield for Zinc Sulfide is 0.49 grams but the actual yield is 0.38 grams. So if 0.38 is divided by 0.49 and multiplied by 100 then the percent yield for Zinc Sulfide would be 77.6%. When it comes to Sodium Chloride, the theoretical yield is 0.58 grams and the actual yield is 0.45 grams. So when 0.45 grams is divided by 0.58 grams and multiplied by 100, the percent yield would be 77.5% of Sodium chloride. The actual yield is directly taken from the mass of the products in the experiment while the theoretical yield is determined by using stoichiometric calculations.
Calculate the following items: (a) The percentage of excess carbon furnished, based on the principal reaction. (b) The percentage conversion of Fe2O3 to Fe. (c) The pounds of carbon used up and the pounds of CO produced per ton of Fe2O3 charged. (d) What is the selectivity in this process (of Fe with respect to FeO)? Solution Setting up the mole equivalent for the principal reaction as follows; Fe_2 O_3 + 3C → 2Fe + 3CO Initial mass: 1 100 lb 300 lb - - Mass at time, t: - - 600 lb Molar mass: 160 12 56 Number of moles: 6.875 25.00 10.714 Mole equivalent: 6.875 8.333 5.357 In addition, setting up the mole equivalent for the undesired side reaction as follows; Fe_2 O_3 + C → 2FeO + CO Initial mass: 1 100 lb 300 lb - - Mass at time, t: - - 91.5 lb Molar mass: 160 12 72 Number of moles: 6.875 25.00
SYSTEM SUITABILITY THEORETICAL PLATES: A standard solution of 25 µg mL-1of Amoxicillin trihydrate (in triplicate) was prepared and same was injected, then the system suitability parameters were calculated. Theoretical plates per meter Theoretical plates per meter were calculated from the data obtained from the peak using the following expression n = (5.54Vr2)/LWh2 Theoretical plates per column Theoretical plates column were calculated from the data obtained from the peak. n = (5.54Vr2)/Wh2 Where, ‘n’ is number of theoretical plates per meter, ‘Vr’ is the distance along the base line between the point of injection and a perpendicular dropped from the maximum of the peak of interest and ‘Wh’ is the width of the peak of interest at half peak
n=cV n=1.00 mol dm^(-3)×(25 dm^3±0.16%)/1000=0.025 mol±0.16 % The enthalpy of neutralization is then calculated. ∆H=(-1356.5 J±3.104% )/(0.025 mol±0.16%)=-54260 J 〖mol〗^(-1)±3.3 % ∆H=-54260 J m〖ol〗^(-1)±3.3%÷1000=-54 kJ 〖mol〗^(-1)±3.3 % Another way to calculate the enthalpy of neutralization is to assume the density of the solution to be equal to the density of water in order to assume the mass of the solution. 1.00 g 〖cm〗^(-3)×50 cm^3±0.96 %= 50.00 g ±0.96 % The heat released can then be calculated using the assumed mass. q=50.00 g±0.96 % ×4.18 J g^(-1) ℃^(-1)×6.40℃±3.1 %=1337.6 J±4.06 % ∆H=(-1337.6 J±4.06 %)/(0.025 mol ±0.16 %)=-53504 J m〖ol〗^(-1)±4.22 % ∆H=-53504 J m〖ol〗^(-1)±4.22 %÷1000=-54 kJ m〖ol〗^(-1)±4.22 % Conclusion and
Aim The purpose of this experiment was to use fractional distillation technique to separate cyclohexane and toluene. Background Information Distillation is a technique which is used for separating two or more volatile products based on differences in their boiling points. Distillation can be used to separate a volatile solvent from a non-volatile product and separate a volatile product from non-volatile impurities. Simple distillation consists of a round-bottom flask, a distilling head, a condenser, an adapter and a receiver which are used to separate compounds where one is considerably more volatile than the other compound. This distillation is performed in one step.
Chemistry IA – Kinetic Experiments Practice Internal Assessment Investigating the relationship between KI concentration and its rate of reaction with H2O2, which is measured using a spectrophotometer. Research Question How will changing the concentration of KI affect its rate of reaction with hydrogen peroxide? Calculated as inverse of time taken for the blue-black coloration of tri-iodide ion and starch solution, measured using a spectrophotometer. Introduction: The rate of reaction of a chemical reaction can be affected by several factors, one which is the concentration of the reactant(s). According to the collision theory, it tells us that as the concentration of the reactant increases, there will be an increase in the amount of molecules,
Below shows the energy profile diagram for an endothermic reaction. Graph 1.2: Energy profile diagram for an endothermic reaction ￼￼￼￼￼￼Ea reactant product ￼￼￼￼Progress of reaction In this experiment, NaCl will be used. The dissociation equation is given as: NaCl(s)!Na+(aq) + Cl–1(aq) RESEARCH QUESTION What is the enthalpy change of solution where a constant mass of 5g of sodium chloride is added to a constant volume of 100 cm3 of water by recording the change in temperature over time? HYPOTHESIS The enthalpy change would be endothermic. TABLE OF VARIABLES ￼￼￼Independent Variable ￼￼￼￼￼￼￼Method of measurement ￼￼￼￼Time ￼￼￼￼A stopwatch is used to take time for each varied temperature reading.
Title : Determination of chemical formula of hydrate Aim To determine the chemical formula of hydrated Copper (II) sulphate, CuSO4 Research Background “When the chemical is heated the hydrate will convert to an anhydrous ionic compound (this means the water will leave it). The moles of H2O will be determined by assuming the amount of mass lost by heating is the mass of the evaporated H2O. The moles of the CuSO4 (the white substance after heating) can be calculated from the mass of the white crystals. Using the molar ratio of moles of CuSO4 to moles of H2O, one can determine the chemical formula of the hydrate.” Apparatus and materials Apparatus and Materials used Quantity Crucible and lid Tripod stand Clay triangle Wire gauze White tile
In Section A, the average mass of the 50 ml beaker was weighed 3 times using 2 different electronic balances. The final average mass recorded was 33.73g. The volume of distilled water needed was calculated from the mass of water using the density= 0.9971g/mL in Section B. The volume of water needed was transferred using pipette, graduated cylinder and Erlenmeyer flask respectively. In Section C, a pipette was calibrated by measuring the water temperature and the density was determined.
For each test, the limiting reagent is found by multiplying the number of moles of the reactant by 1 mole of Ca(OH)2 and dividing then by a number of moles of reactant from the reaction. The lowest answer in each test will be the limiting reagent. To find a theoretical yield, the limiting reagent was multiplied by the molar mass of Ca(OH)2 and
Methodology: The distillation column was analyzed theoretically using McCabe Thiele to establish the number of stages required for separation. The vapor-liquid equilibrium (VLE) data for methanol and 2-propanol was used to plot curves of methanol-vapor fraction versus methanol-liquid fraction, and methanol liquid-vapor fraction versus temperature. III. Results: From the results, the average efficiency was 0.4308, 0.3778, and 0.4956 at 0.57kW supplied (30.58 mL/min Feed; 26.30 mL/min Boil Up), 0.94kW (30.58 mL/min Feed; 52.96 mL/min Boil Up), and 1.27kW (30.58 mL/min Feed; 77.50 mL/min Boil Up) respectively. From the experiment, it was observed that the quality
The purpose of this experiment was to create two 40 mL buffers and evaluate its buffer capacity at pH 4. To do this, buffer #1 consisted of the mixture of 0.5003 M acetic acid and .50 M sodium acetate, while buffer #2 consisted of the mixture .5003 M acetic acid and .4289 M NaOH. Within each mixture, there is a ratio of conjugate acid to conjugate base. By using the Henderson Hasselbalch equation, the volume for the base and acid to buffer the pH of solution at 4.0 were calculated. Two titration were performed for each buffer: HCl and NaOH.