3. Since dealing with enzymes, it was important to choose well the different temperatures for the experiment – for example, not making all five temperatures high because then it would not take effect. Observation during the experiment After the digestion of the gelatines was completed, the silver salts on the film peace chipped off and left a clear piece of film. The silver salts that had fallen were left as a black substance that remained at the bottom of the test tube. The Effect of Temperature Increase on the Digestion rate of Gelatine by Trypsin by the time taken for the silver salts on the exposed film pieces (in trypsin solution) to fall off, leaving clear film pieces: Temperature of the 2% trypsin solution (°C) ±0.5 | Time taken for film pieces to become clear (seconds) ±0.7 – Trial 1 | Time taken for film pieces to become clear (seconds) ±0.7 – Trial 2 | 25 | 186.6 | 184.7 | 35 | 150.0
Introduction: The purpose of this experiment was to determine the Activation Energy of the Hydrogen Peroxide-Iodide reaction. This was found by measuring the rate at which the reaction occurred and plotting this against the natural log of the number of moles of hydrogen peroxide remaining to find the slope. The reaction is carried out in a Potassium Iodide solution, which serves as a catalyst to the reaction. A catalyst is a chemical which increases the rate of a reaction without being consumed. Catalysts operate by decreasing the value of the activation energy for the reaction.
The success of this experiment was dependent largely on how well the apparatus was setup to ensure proper distillation of the solution. If the separate parts of the apparatus weren’t put together well is can case loss of solution through evaporation. The apparatus should also have no water in it since the presence of water can alter the intended results. The electrical attraction between water molecules causes dipole pulls which make t difficult to separate the molecules that move closer together. This raises the boiling point.
How does concentration change the rate of reaction of limestone and Hydrochloric acid? By Chris Wilson Contents Page Introduction page 3 Preliminary and results Page 3 and 4 Method page 5 Prediction page 5 Table of Results Page 6 Table of averages page 7 Evaluation page 8 Conclusion Page 8, 9 and 10 How does concentration change the rate of reaction of limestone and Hydrochloric acid? The four things capable of changing the rate of reaction are, the surface area, the concentration, changing the temperature or adding a catalyst. In this experiment I will change the concentration of the acid as it is easy to control and easy to measure. I chose not to change the surface area due to the fact that it is very difficult to measure exactly the surface areas as a fine calibration is needed to measure this.
The Solubility of Potassium Nitrate Introduction The purpose of this experiment was to observe how temperature affected the solubility of solid potassium nitrate that was put in different solvents. The temperature was not the other thing that was being varied to observe the solubility of potassium nitrate, the amount solute was also varied and the kinds of solvents in this experiment were varied. The nature of each solvent changes due to the common ion effect which is basically means that the concentration of a soluble salt is reduced if there is a common ion with that salt. Also potassium nitrate solubility in basic and acidic places was also determined, to see if it affected the temperature. The moles of KNO3 s/ Kg solvent were needed to calculate the correct molal concentration.
I thought distillation would remove the salt. The benzoic acid I wasn’t really sure about. B. If each step isn’t done correctly before moving on to the next step the percent for error rises. C. The sand recovery percentage being higher than the original sand percentage could take place if all the iron was not removed from the mixture.
To investigate the effect of concentration on the time of reaction between two chemicals: hydrochloric acid (HCl) and sodium thiosulphate (Na2 S2 O3). Introduction In the experiment I am going to investigate the reaction between sodium thiosulphate and different concentrations of hydrochloric acid and how long does this take. I want to find out if the more concentrated the hydrochloric acid does this make the speed of reaction slower or faster? Or does it have no effect? This is the equation of the reaction.
One of the applications of Hess' Law is to determine the enthalpy change for a reaction by combining other reactions to get the desired reaction, then combining the enthalpy changes for the reactions to get delta H for the reaction under consideration. An exothermic enthalpy change is always Assessed Practical: Planning Introduction: The aim of this experiment is to find the enthalpy change for the decomposition of sodium hydrogen carbonate. 2NaHCO = Na2CO3 + CO2 + H2O Using the enthalpy change of the following reactions. Sodium Hydrogen Carbonate: NaHCO3 + HCl = NaCl + CO2 + H2O Sodium carbonate: Na2CO3 + 2HCl = 2NaCl + CO2 + H2O Apparatus Sodium hydrogen carbonate Sodium carbonate Polystyrene Cup x 2 Measuring cylinder 50cm³ x 2 Weighing scale Weighing boats Thermometer degrees Spatula HCl acid 2M Prediction Background Information Hess' Law states that the enthalpy change for a reaction is the same whether the reaction occurs directly or in steps. This is a direct consequence of the fact that enthalpy, is a state function.
The powder that remains will have lost some mass as smoke, but this resultant mass is still more than the mass of the metal that was burnt. Burning magnesium in air is a chemical reaction called oxidation and the compound produced is totally different from the two elements that have been combined. Each element is made up of atoms and the compound is made up of two elements joined together. The chemical formula for the reaction is below; 2Mg + O2 --> 2MgO Magnesium + Oxygen -> Magnesium Oxide The equation above shows that magnesium and oxygen have combined as the product of the reaction, their mass of each element has also combined in the reaction. Magnesium is a very reactive metal which when heated burns with a white flame.
1.5- Before starting this experiment we didn’t know how drastically the rhubarb cell would shrink, or if this experiment would actually be a success. We learnt that Osmosis and Diffusion played a very important part to our experiment and we could also document at just how much the salt water concentrations affected the cells. 2. Experimental Method and Design. 2.1 Equipment: • 3x 100ml Beakers.