Abstract: The purpose of this experiment was to identify given Unknown White Compound by conducting various test and learning how to use lab techniques. Tests that are used during this experiment were a flame test, ion test, pH test, and conductivity test. The results drawn from these tests confirmed the identity of the Unknown White Compound to be sodium acetate (NaC2H3O2) because there were no presence of ions and sodium has a strong persistent orange color. The compound then will be synthesized with the compounds Na2CO3 and HC2H3O2 to find percent yield.
The compounds tested in included the unknown, Calcium Nitrate, Calcium Chloride, Calcium Carbonate, Sodium Chloride, Potassium Chloride, Magnesium Chloride, and Ammonium Chloride. The next test was the pH test. In this test, the aqueous solutions from the flame tests were used again. A piece of pH paper was dipped into the aqueous solutions, a different piece for each solution. The ensuing coloration of the paper was compared to the pH scale and the
Sodium Bicarbonate mixed with Hydrochloric acid. The chemical reaction observed showed that there was fizzing and bubbling, this is evidence that a new gas was being produced. This new gas, CO2 was generated from the reaction. After the fizzing stopped a liquid was leftover leading me to conclude the liquid leftover leading me to conclude the liquid leftover was the NaCl and H2O 4. You found a sample of a solution that has a faint odor resembling vinegar (an acid).
Exercise 14: Unknown Identification Lab Report The purpose of the study was to identify the unknown bacterium using various biochemical tests in addition to using scientific methods in determining the outcome of the hypothesis. Each biochemical test will help determine the bacteria based on specific characteristics of each organism. I was giving unknown number 232. The first procedure that needed to be done after obtaining unknown bacterial mixture was to isolate the two bacteria in a pure culture using the streak plate method described in Microbiology Laboratory Manual Eight Edition. The material used was trypticase soy agar (TSA) plate, nutrient plate, starch agar, hydrogen peroxide, iodine reagent and microscope.
Identification of bacteria within Unknown Culture #21 In this experiment, an unknown culture of two different types of bacteria was assigned to each person, a number of tests were performed to isolate and identify these bacterial cells. Based on knowledge from the previous experiments completed in lab, a basic understanding of each type of bacteria was used to create a flow chart that would aid the process of identifying the unknown bacteria within the culture. A gram stain that is performed initially will narrow down the types of tests certain bacteria will and will not respond to. In addition to the gram stain, some of the tests that were used include, a catalase test, an Eosin methylene blue (EMB) agar test, a bile esculin test, and a 6.5% sodium chloride (NaCl) test.
When Unknown Substance D was observed on the hot plate, it turned a brownish color and into a sticky liquid at two minutes just like the known covalent compounds, proving Unknown D had a low melting point. Ionic compounds cannot melt because they are made up of atoms with full opposite charges, so their intermolecular forces are stronger. While ionic compounds do not melt, covalent compounds do because their atoms only have slight charges, so their intermolecular forces are weaker. Since ionic compounds have stronger intermolecular forces, it takes more energy to pull the molecules apart. Opposite of ionic compounds, covalent compounds have weaker intermolecular forces, so it takes less heat to pull the molecules apart, which makes covalent
This was used to identify which of the two is AgNO3 and which is Na2CO3. Once Na2CO3 has been identified, KC2H3O2 can be found because KC2H3O2 is the only substance that will not react with Na2CO3, so
The Cysteine desulfurase test implies that the bacteria can hydrolyze cysteine to produce hydrogen sulfide. Lastly, the Citrate utilizing enzymes test came back positive which indicates that the bacteria has the ability to use citrate as a sole carbon energy source for growth and to produce alkaline
To check the conductivity of the solid it was put in a small dish and was tested with the conductive meter. Then t o check solubility of the unknown solid it was mixed into a small amount of water to see test solubility. The next text was to conduct a ph test using some aqueous solution of the unknow solid we applied that to a ph paper strip to show ph. Another test was checking the solid’s reactivity. Using water mixed with
If the stone was left in the vinegar for a longer period of time, then the pH level of the vinegar would have a greater change. Because it has had more time to react with the stone. Yes the hypothesis was supported, we tested the pH of the vinegar in the beginning and it was 2. After 10 minutes of vinegar with limestone the pH changed to 3. The material which was affected most by the acid rain was the limestone.
A chemical change has occurred when a new substance has been formed and the original substance(s) cannot be changed back to it’s/ their original state. The chemical bond formed could possibly be broken, but it could be extremely hard. Also, in a chemical reaction, usually a drastic change occurs, almost immediately. This is how you can tell if a chemical change has occurred.
In order to proceed with the experiment certain materials were needed in order to be able to perform well. The materials needed were as follows, unknown liquid, unknown solid, water, and acetone. The first thing that had to be done was to take the mass of a 25 ml flask and stopper which we got a mass of 31.54g. After that we filled the flask plus stopper with H2O and measure a mass of 60.50g. After taking the mass of the water the water was disposed of in the sink. The flask had to be dried to continue with the experiment, we added a small amount of acetone to fasten the drying of the water in the flask.
I can apply this experiment’s concepts to daily life in foods. The majority of chemical reactions that produce heat are combustion reactions. When energy is released, and one gram of a substance is combusted, a fuel value is produced. Fuel values represent heat that is released in a combustion reaction and can be measured by calorimetry. The energy from my body comes from carbohydrates and fats.
It had been seen that this did not occur since the solution was orange, and when the one drop of base was added, then the solution turned yellow meaning that the sodium hydroxide and carbonic acid had
When we added the acid and base to the buffer solution, the colors changed slightly, but the pH remained close to the original pH. We were able to tell that the water changed pH when the acid or base was added because the pH indicator (cabbage juice) changed the neutral water to a different
