After cooling, the flask was weighed in an analytical balance. The experimental molar mass was 45.56g, which is closely identical to the 46.068g of the molar mass of ethanol. The percent error between the two values is 1.10%, the probable sources of error are the following: the size of the tiny hole in the aluminum foil, measurement of the temperature in the thermometer, and measurement of the initial volume of the flask. The recommendation for the experiment is to dry the flask completely before measuring the initial mass and to closely observe if the temperature of the water bath is
1. For the demo experiment, the balanced chemical equation is as follows: (NH4)2Cr2O7(s)=Cr2O3(s)+N2(g)+4H2O(g). After the lightning of Ammonium dichromate, Chromium (III) oxide was formed while the Nitrogen and Water escaped into the atmosphere in a gaseous phase. Ammonium dichromate((NH4)2Cr2O7) gave rise to Chromium (III) oxide (Cr2O3), Nitrogen Gas(N2) and water (H2O) In terms of microscopic level, the ratio between reactants and products is as follows. One mole of Ammonium dichromate will give rise to one mole of 1 mole of Chromium (III) oxide and 1 mole of Nitrogen gas and 4 moles of Water is gaseous phase.
Standardization of NaOH solution Accurately weigh out a sample of approximately 0.3-0.4 g of primary standard potassium hydrogen phthalate, KHPh, which has been previously dried at 120°C. Do not use more than 0.4 g. To obtain an accurate mass, weigh the sample on weighing paper, slide it into a clean (but not necessarily dry) 250 mL Erlenmeyer flask and reweigh the paper to account for any KHPh that may remain on it. Dissolve the KHPh sample in about 50 mL of CO2-free water and add 2-3 drops of 0.1% phenolphthalein indicator. Begin adding the approximately 0.1 M sodium hydroxide solution from the buret while continuously swirling the flask contents. Do not open the stopcock completely.
To then find the percent water divide the water mass by the hydrate mass and multiply by 100 since the number is a percent. The water percent is determined to be 42.06%. To find a percent error, a theoretical percent water must be used. To find the theoretical percent error divide the mass of water by the mass of magnesium sulfate heptahydrate and multiply by 100 to get a percent. The theoretical percent water is
Remove the plunger from the syringe barrel and place the ten leaf discs into the syringe barrel. 10. Place the plunger back into the syringe barrel then carefully push the plunger down until there are 3cm3 of air are left inside (make you sure no leaves are crushed) 11. Pull 5cm3 of Sodium hydrogen carbonate into the syringe. In the case of the leaf discs being stuck on the sides of the barrel, tap the syringe to suspend them in the solution.
Experiment 1 In the first experiment, half a gram of magnesium was combined with 3 milliliters of hydrochloric acid in a glass beaker. The magnesium looked like a gray powder. The hydrochloric acid appeared to be clear liquid and looked very similar to rubbing alcohol. Before, the reaction took place the magnesium and hydrochloric acid weighed 4.44 grams when weighed together. Once the magnesium and the hydrochloric acid were mixed together, the bottom of the beaker felt warm and it started to foam.
Substrate concentration basically means the amount used for the substrate. The substrate in our experiment was 0.1% hydrogen peroxide. The 0.1% is the concentration amount. Just like temperature and pH, substrate concentration can speed the reaction only up to a certain limit. When we mixed pH 3 enzyme tube with substrate tube, we used 0.3 mL of hydrogen peroxide, but if we were to increase the amount, then the experiment would have been faster.
The highest reaction rate during the lab was with a temperature of 30℃, which makes sense since catalase is found in the liver at a temperature of 37℃ (Buddies, 2012). The temperature of 30℃ was the closest to catalase’s normal temperature which is why it yielded the highest reaction rate. Therefore, in order for the body to discard the toxic hydrogen peroxide, the body must constantly maintain a temperature of 37℃ to prevent cell damage (Sciencing, 2018). At extreme temperatures, an enzyme’s activity will decrease because enzymes have a very narrow range in which they can effectively function. The results from the lab show that at 100℃, catalase has no reaction with hydrogen peroxide.
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