For the first trial, 2 dry evaporating dishes were weighed on the balance, and their masses were recorded. The first dish was 71.74 grams by mass, while the second dish was 52.03 grams by mass. We added 2 grams of unknown mixture to the first evaporating dish, and we weighted it on the balance and recorded its mass. The mass of this dish was 74.74g. Then, the first evaporating dish was put on the clay triangle using crucible tongs on the Bunsen burner in the hood area. The mixture was heated, and there was a gas that was produced which was NH4CL. After the NH4CL was removed, we took the evaporating dish using tongs and it was left to allow it to cool. After the dish was cooled down, the dish was placed on the balance and weighted again after heating (McHugh 46). …show more content…
Dish 1 after heating. m = 0.86g. We brought a beaker, and we filled it with 20 ml of water. Then, the water was added on the first evaporating dish and stirred to take in the Nacl solid. Some of the water and the Nacl were poured from the first evaporating dish to the second evaporating dish. Next, we added 10 ml of water using a beaker to the evaporation dish 1 and then pour off some of the evaporation dish 1 to the evaporation dish 2 to make sure NaCl has gone from the evaporation dish 1.We put a watch glass on the evaporation dish 2 that has NaCl and weight it on a balance and record its mass. m= 149.35g. Later, we brought an electric hot plate, and we put the evaporation dish1 and evaporation dish 2 on it in order to heat these dishes. The first evaporation dish has sand and water while the second evaporation dish has Nacl and water. In the first evaporation dish, water was gone, and the sand was remained. Eventually, we took the dish off the electric hotplate and left it for a while until it cool then we weighted the sand. Evaporation dish 1 with sand after heating m=
Take the evaporating dish off the heat, let it cool, and record the mass of the evaporating dish and anhydrous salt.
The experiment is aimed at giving a better understatement of osmosis process and the different conditions in which osmosis occurs.
The presence of coliforms in a water supply can mean there is fecal contamination circulating in that water, which we tested for in this experiment. It is hypothesized that all of the water supplies will exhibit the presence of fecal coliforms, because they are all outside sources of water that have road runoff, sewage waste and animals defecating in them. We gathered several water samples and inoculated lactose broth with these water samples which tested for fermentation and helped determine if coliforms were present. Then if there was possible coliforms present, we placed them on either an Endo agar
A hot plate is acquired and plugged in and if left to warm up. Fill two beakers with 0.075kg of water and record the temperature using a thermometer and record it. Place one of the beakers onto the hot plate and drop one of the metal objects in. Wait for the water to boil and wait two minutes. Take the object out of the water and drop it into the other beaker. Take the temperature of the beaker and record the rise in temperature.
(Materials and methods) Five plastic Solo cups were arranged with even amounts of soil. Numbers 1-5 were written on each plastic...
The mixture was poured through a weight filter paper and Sucrose washed with a 5ml of dichloromethane. The resulting solid was left in a breaker to dry for one week, to be measured. Left it in the drawer to dry out for a week and weighted it to find the sucrose amount recovered amount.
The data in both Table 2 and Graph 1 show that as the concentration of sodium chloride (%) is increased from 0% to 10% when there is a significant increase in the % change in mass, thus also the rate of osmosis. Between concentrations 0% and 2% there was a rapid % change in mass. At 0% NaCl the % change in mass was +1.63% indicating that the potato piece had gained water because the concentration of solute must have been higher in the potato than in the solution. The % change in mass at 2% NaCl concentration was -8.82%, the negative indicates that the potato piece had lost water as the concentration of solute was higher in the solution than the potato piece. From 2% to 4% NaCl solution the %change in mass was slightly less rapid but still had an increase from -8.82 to -14.7, respectively. The graph had a slower decreasing trend from 4% NaCl solution onwards, this can be seen from the gradual plateau of the graph. The slowest increase in %change in mass of -0.04% was between 6% to 8% valued at -16.5% and -16.9%, respectively. The % change in mass increased slightly from -16.9% to -17.5% between 8% to 10% NaCl concentration. This suggests that the rate of osmosis had begun to stabilize and may be the result of the concentrations of both the
This experiment required the used of reflux to heat the mixture because it is a technique that does not lose any liquid due to evaporation. A reflux apparatus is capped so that vapors do not escape and the system is contained resulting in a larger end product. The reason for using a distillation technique was to produce an individual component of the starting compound, here 1-propanol and 2-pentanol. Drying is a very important step because if the product is wet, it will have added incorrect water weight. Before drying, first the product must be separated from the organic layer. The reason for applying the reflux method over simple distillation is simply because the reflux is set up to return the condensed distillate to the flask. This allows it to boil, yet lose no solution. Simple
The lab activity that I will be writing an evaluation on is Solar Heating. There are several reasons that I chose this lab activity. First, I think students should understand that earth’s surface is unevenly heated by the sun. It is this uneven heating of the surface that creates wind, affects the weather, and makes the water cycle occur (Martin, Sexton, and Franklin, 2009). The materials that are needed are not excessive and are easily obtained. Finally, I think that this activity is simple to perform for younger middle schoolers. The directions are not too complex, so the students can focus more on their conclusions while not being overwhelmed with procedures.
In a 100ml beaker 30mls of water was placed the temperature of the water was recorded. 1 teaspoon of Ammonium Nitrate was added to the water and stirred until dissolved. The temperature was then recorded again. This was to see the difference between the initial temperature and the final temperature.
Lastly, during the experiment, tap water was used to measure the change in temperature. However, tap water contains several unknown ions and minerals and every time when the conical flask was refilled with water, the concentration of those ions and minerals may vary. Furthermore, when calculating the heat energy, we used the specific heat capacity used of the water; however, the unknown minerals may affect the specific heat capacity of the
Evaporation is part of our everyday lives. After washing the dishes, after taking a shower, and many more signs of evaporation in our everyday lives, but does every type of liquid evaporate at the same rate? Sometimes liquids may be sitting in one dry place and its molecules might turn into gas molecules, that is the process of evaporation. When energy in certain molecules reaches a specific level, those molecules have a phase change. Evaporation occurs when molecules escape from their liquid and form into vapor. If there was a puddle of water outside, and it was a windy day, the air from the wind can cause an increased rate of evaporation. When a molecule
Yuan’s experiment was done by measuring evaporation from bare soil versus soil covered with gravel mulch. Yuan goes into depth of how the experiment was arranged so both bare soil and various thickness of gravel-covered soil was exposed to exact environmental conditions. A constant air speed, humidity, and three differing temperature conditions were all ...
I am doing my science fair project on the ability of three different plastic wraps to prevent evaporation. I am motivated to do this project for various reasons: my family keeps a lot has a lot of leftovers and we hunt and have a deep freezer full of game meat and I want to know which plastic wrap would be best for preserving the hydration and freshness of foods. I also want to do this experiment because we keep a lot of plastic wrap in our house without knowing which one is better for preserving foods. In order to do this project, I need to have a better understanding of plastic, PET plastics, PVC plastics, and PVDC plastics. Also, I needed to research the importance of evaporation.
Evaporation is the process in which a liquid turns to a vapor without its temperature reaching boiling point. The rate of evaporation rises if the liquid is warmed up. The temperature of a liquid decreases as it evaporates because the evaporating molecules remove energy from the liquid. ¨Water is the most ordinary substance on Earth. It covers 70 percent of the world’s surface. Each water molecule is made up of two atoms of hydrogen and one of oxygen. Water freezes at 32°F (0°) and boils at 212°F (100°). Ninety-seven percent of Earth’s water is in the oceans and two percent is in the form of ice or snow. Movement of water around the Earth is called the water cycle. Water vapor in the atmosphere condenses to fall as rain, flows through rivers