In account for weighing, because the sample is an unknown, students do not know what the sample is or what it contains. The three samples of the unknown A had to be weighed around 0.4000g. If the sample was not weighed at a quick rate, it would collect moisture from the air and disturb the weighing process by causing it to be higher than expected. Because three samples had to be weighed out at the same time, there was plenty of time for the unknown to collect moisture from the air allowing the sample to contain more moisture and less of the unknown sample. Also, the weather could affect the weight of the sample along with the season. During the summer time, humidity is more common than in the winter. With humidity comes an abundant amount of moisture within an area, specifically a laboratory. Before conducting the experiment, the equipment had to be washed with the filter water (or “good” H2O) provided. If any of …show more content…
Majority of the experiment was conducted in a lighted area and this does not allow for a 100% reaction. Silver nitrate responds to light causing it to change its properities. It was important for students to quickly conduct the portions of the lab where silver nitrate was used. If not, then a less than 100% reaction would occur. It was also important for students to keep the silver nitrate in a dark area until needed. Finally, some source of errors caused by students, known as human errors, include the following: 1) not using the same balance when weighing both the gooch crucibles and the unknown sample, 2) making sure the balance was cleaned before usage, 3) making sure the samples were dried and cooled before weighing, 4) crucibles being left in the oven for longer than necessary, 5) not rinsing enough or over-rinsing during preparation of product, 6) not leaving enough of the sample in the test tube to be tested for the absence of silver before placing the product in the gooch crucible to be
Each scenario below describes an operational error that can lead to low yield and/or low purity of product(s) or during the extractions of this experiment. In each case specify the component(s) whose percentage(s) would be too high or too low, and briefly explain your answer.
Wash your hands and all of the equipment with mild soap and water. As a final rinse on the equipment, use deionized water. Dry all equipment thoroughly.
The purpose of the lab copper- silver nitrate reaction is to find the mole relationships between reactants and products. My hypothesis was that the mole relationship between silver and copper will be 2 mol Cu: 1 mol Ag ratio. My hypothesis is supported by the data I found during the lab. First evidence, in the beginning of my calculation I have to determine the mass of copper that reacted during the experiment and converted to moles of copper and got .0033 moles of Cu. Next, I determined the mass of silver produced during the experiment and converted into moles of silver and got .0063 moles of Ag. After I found the moles of copper and silver, I determined the value of the ratio of .0063 moles Ag /.0033 moles Cu and got 1.90 moles. 1.90 mol
13) When the tray is thoroughly dry, determine its mass. Record the mass in the data table. You have to wait until day three to weigh the copper.
The weight of each 50ml beaker (used for weighing the mass of dissolved Potassium chloride after the evaporation of water) should be recorded. If the experimenter were to weigh the mass of one beaker and take it as a default mass, the latter may be a source of error.
Did all of the silver nitrate react in this experiment? Show all calculations and explain your reasoning.
The purpose of this lab was to become familiar with the three different balances and two different methods used to find the weight and mass of chemicals and compounds in the ChemLab program. The lab was performed by using three different types of balances, and the direct weighing and weighing by difference methods.
In this lab, my group concluded that there are 1,992 beans in the large jar display. The true value of the beans in the jar was 2,051. My team’s technique was that we found the tare weight of the beaker with the beans to be 49. 912g. Next we found the overall weight to be 95.301g. Then we found the average mass of ten beans, which was .47 g all together. After we found that we subtracted the mass of the beaker with the beans from the tare weight to find the weight of the beans. After my team found the weight of the beans we divided it by the average weight of the beans and got 97 beans. We repeated these steps with the information from the large jar and got our estimate of 1,992 beans. Our estimate was close to the actual amount of beans, we were only 59 beans away from the true amount. Our peers in other groups did well too, there averages ranged closely from 1,900 to 2,000 beans in the jar.
Modern sellers use TDS meters as a means to deduce the particle count through the use of conductivity testing, and most of them know how dishonest this is. Colloidal silver is an electro-chemical capacitor, with ever changing electrical properties. This means that all electrical measurements of it are meaningless, because the results are randomized. One cannot predict the specific electrical properties of a colloidal silver solution from one minute to the next. Because the solution is a capacitor, it will often give a reading that is off scale if it is measured for resistance for long enough, because the current that is injected by the resistance testing will charge the solution to an opposite polarity and choke off the current. These phenomena are typical for colloidal metal solutions. Most people will get a more accurate assessment of a solution's strength by making a visual estimate that is based upon its color. At least the color is independent of the capacitance. When colloidal silver solutions were sold by pharmaceutical companies as standard medicines at the beginning of the Twentieth Century, they used light-testing equipment to standardize their products. Most of that history was well covered up, for the sake of the vaccine and antibiotic
For the experiment, our table divides into two groups: group (a), and group (b) each group will do both experiments twice. Group (a) using precipitation reaction to remove the silver, and group (b) using oxidation-reduction reaction to remove silver. Group (a) took 2.5m CaCl2 put into 25 mL test tube mix with 5mL AgNO3. Group (b) place the copper metal in the test tube plus 5 mL of AgNO3 but this reaction took 20 minutes to completely remove the silver. Also, each group weighs a piece of filter paper for use in separating the silver later: (.291g), and (.285g). After completing the reactions, we took each graduated cylinder containing the silver and put it on top of filter paper and then put inside the Buchner funnel on top of filtration flask,
There is some variation as to the levels of concentration in urine in regard to age and health status of individuals. Certain disease processes and age, factor into the excretion of nitrates and nitrites via the urinary tract. For instance, infants pose a greater susceptibility for toxicity. The presence of bacteria in their gastrointestinal tract elicit a greater conversion percentage of nitrates to nitrites. This conversion creates more nitric oxide metabolites which can cause a reduction in available oxygen in the blood. The elimination of nitrates and nitrites concentrated in urine may give an indication of the synthases taking place in the body. Concentration levels may be an indicator for disease processes and may be tested for
D. Before using the glass electrodes, they must be washed in warm soapy water and put in the UV steriliser to ensure they are clean and free from bacteria. After the treatment they should be washed and wiped over with disinfectant and sterilised before being used again.
Silver compounds were used in external preparations as disinfectants, including both silver nitrate and silver proteins, which can be used in dilute solution as a drop to prevent conjunctivitis in neonates. Silver nitrate is also sometimes used as a treatment for certain skin diseases in the solid image as a caustic agent for the treatment of certain skin diseases such as corn and pimples. Silver is also used in prostheses, reconstructive orthopedic surgery and heart organs. Silver duramine fluoride appears to be an effective factor in reducing dental caries. Silver acetate is used as an aid to help quit smoking
If using tap water that is not filtered, add 1 teaspoon of a dechlorinating chemical, while filling the tank.
Other factor, which may have had influence on the results is the human's imprecision. The used equipment was as accurate as possible in school laboratory, but still, the titration is made by hand and by eye, which may make mistakes although back titration is the best possible way in school laboratory to check the amount of particular components in mixtures. Other method, which would distinguish between