Baria Chloride Lab

Sodium Chloride is added to the ice to lower the melting point of the ice, which is called ionic dissociation. The sodium chloride is added to the ice in the larger bag in order to keep the dissolving ice from becoming room temperature. Sodium chloride keeps the ice/ slush at a low temperature that allows the ice/slush to start chilling the cream and milk which is located in the smaller bag. The freezing point drops to about -10 degrees Celsius. This allowed the ice/ slush to remain cold at a low temperature. The sodium chloride prevents hydrogen bonds and keeps the water molecules solid. This is called freezing point depression. This is one of the colligative properties of science. Without the temperature dropping, the ice/ slush would not remain cold and crystals would not be able to form in the smaller bag. The crystals create the ice cream’s texture.

1. Place a small amount of wax from a birthday candle into a test tube. Heat gently over a burner flame until the wax melts completely; then allow

Day 1. Michael was coming home for vacation from college. When he got home he found out that

Substances A and B have an appearance of a white solid like. Substances A and B were put into a test tube and on the Bunsen burner. As a result, B melted faster than A. A was slow to melt. The reason why B melted faster than A is because it has a lower boiling point than substance A which made it melt faster. It also shows that A needs more energy than B to be broken down.

To begin Lab 7 of Chem 115, a clean and dry porcelain crucible and its cover were obtained. Next, an iron ring was attached to a ring stand. A clay triangle was placed on top to the ring and a Bunsen burner was placed under the ring. Following the setup for the experiment, the crucible and its cover were placed on the clay triangle and were heated for about five minutes. After, the burner was turned off and the crucible and cover were left to cool to room temperature. Once the crucible and its cover had reached room temperature, tongs were used to move them to a wire gauze. Using the wire guaze, the crucible and its cover were transported to an analytical scale to weigh and record the mass of it. Next, a strip of magnesium was obtained and

6-3: This process is used by cells to manufacture _biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products__

6) Continue heating the crucible for 14 minutes. Watch for signs of a chemical change!

The purpose of this lab was to experimentally and scientifically ascertain the percentage of oxygen in Chem B at Woonsocket High School. It was hypothesized that if the percentage of oxygen is measured experimentally in Chem B at Woonsocket High School, then it would be higher than the percentage of oxygen in dry air, which is 20.95%, because the air is not dry due to moisture in the air from people breathing and the altitude of where the experiment takes place may affect it as well.

In order to gently heat the sample, move the burner back and forth to achieve minimal heating. It is important to not overheat the sample. After heating the sample, turn off the burner and let the sample fully cool with the lid on top. After about ten minutes, lift the crucible lid and observe any changes that occurred to the sample. You must reheat the sample if there are blue-green crystals. Heat the sample until the crystals turn brown. After the sample has fully cooled, measure and record the mass of the crucible with the lid and sample.

After it has cooled, determine the mass of the crucible, and record it in the data table.

To start your experiment you need to get all your materials. You will need,three cups, three shells, acid, measuring spoons, electronic balance and water. First we're gonna pour 120 ml (water) in the three cups ( tps whole ⅛ ). Then were gonna put one shell in each cup and let them soak in the acid. Then we're gonna take them out and measure the different weight. Cup A will need a whole tps and the rest filled with water. Cup B is gonna need ¼ tps and the rest filled with water. Cup C will need ½ tps and the rest water. gonna need

Calcium chloride has a consistency of salt, they are white little flake and particles. calcium chloride at room temperature is a solid, it is used for dust control it has a generic formula of

“Acid/Base” lab’s purpose was to introduce extractions of one of the four neutral organic compounds (4-chlorobenzophene, biphenyl, trans-stilbene, and trans-chalcone). We then were asked to test the solubility of our selected neutral compound with hexane, water, methanol, and ethyl acetate to find the solvent that only dissolved the neutral compound while introduced to heat. Once the solvent was chosen, we purified the compound by recrystallization, and then concluded that my neutral organic compound was trans-stilbene.

Subsequently, two porcelain crucibles were used, weighed, and heated for about 10 minutes and then placed into a desiccator to cool. The two empty porcelain crucibles were first heated because the heat would vaporize any impurities that were originally on the crucible. The first crucible weighed 11.9047 g and the second crucible weighed 12.3735 g. Once the mass of the two crucibles

Firstly, after removed from the Bunsen burner, the crucible was not given time to cool down before being weighed. Weighing a hot crucible can affect the accuracy of measurements by making the crucible appear to weigh heavier, causing the results to be overstated. Secondly, as state in the paragraph above, both samples did not weigh exactly 2g. In trial 1, the sample weighed slightly less than 2g but in trial 2 the sample weighed slightly more than 2g. Consequently, the net weight for the solid in trial 1 was understated and the net weight for the solid in trial 2 was slightly