Condensation formed inside the jar and under the lid of the jar. 2. Which processes are not represented? How could the model be altered to include these processes? Answer = The processes of the water cycle not represented were sublimation, precipitation, transpiration, surface run-off, infiltration, and percolation.
* Water freezes at zero degrees Celsius. * Water vaporizes at a hundred degrees Celsius. Myths about Water - Drinking water will reduce blood alcohol level in your body. MYTH!
The salts will be dissolved in distilled water by small quantities until the reaction reaches When ionic compounds dissolve in water, they either absorb energy from or release energy to the surroundings. If a chemical reaction absorbs heat from the surroundings, it is an endothermic reaction. If a solution releases heat to its surroundings, it is an exothermic reaction. The enthalpy of dissolution is the enthalpy change associated with the dissolution of a substance in a solvent at a constant pressure. The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies.
The simple addition of water to FeSO4 will not lead to the formation of FeSO4•7H2O. Determination of the number of molecules of water in a hydrate. If you do not know how many molecules of water are in one molecule of hydrate and want to find this out, it can be done by measuring the masses of the hydrate and anhydrous compound formed after the heating. For example, let’s assume that we do not know how many water molecules are attached to BaCl2. Let’s call this number X.
CHEMISTRY September 25, 2010 Experiment #5: Percentage of water in a Hydrate Summary of Principles In this lab, students will calculate the amount of water in an unknown hydrate. A hydrate is a compound with a specific number of water molecules associated with the ions of that compound. A hydrate may form when an anhydrous compound is exposed to atmospheric water or when the ionic compound is crystallized from an aqueous solution. An anhydrous compound is a substance without water. There are two parts to this lab.
As it was uncapped some of the heat would have been lost to the air and as one of our assumptions was that the heat released by the reactions was used only to heat the water the value calculated will be off. The consequence of this source of error would be the measurement of a lesser final temperature and therefore the heat of reaction calculated would also be less. Another source of error could be due to the use of a white Styrofoam cup and the dissolving of white sodium hydroxide pellets. It would be easy to miss if the reaction had yet to fully take place meaning the final temperature recorded would be lower and heat of reaction calculated would be lower. A final possible source of error could be that not a precisely even amount of HCl and NaOH were used for the neutralization reactions in part two and three.
The way to calculate a local rise in temperature with increasing altitude would be to calculate the environmental lapse rate. This could be related to the total rainfall and altitude but is omitted for this investigation. Air being forced up a mountain side for example would begin to cool. The further it is pushed upwards, i.e. the higher the altitude the cooler the air becomes in general.
6. Addition of DNS at the end of the incubation period stopped the reaction by denaturing sucrase. Explain why it is important to denature sucrase before measuring product concentration. RESULTS See Table 1: Effect of pH on Sucrase Activity See Graph, Effect of pH on Sucrase Activity 1. State the optimum pH for sucrase activity and describe how sucrase activity changes at more acidic and more alkaline pH values.
Also, there is a limit of how much solute you can put in the solvent and you should not exceed that certain percentage. If you put too much solute and end up having more solute than the water, the freezing point will start going back up again because the solute won’t be able to dissolve within the solvent at such a big quantity. Another limitation is that the concentration of the solvent in the mixture should be at least 10% and if it’s lower, the freezing point depression might not be affected because the amount of solute used will be too low. Lastly, the solution must be cooled to a lower temperature than the pure solvent in order to freeze. If water was used as the solvent, it has a freezing point of 0 °C and the solution will freeze at even a lower temperature so you have to put it somewhere cool like a freezer.
The dorsal view then had features such as compound eyes, thorax segments, and the exoskeleton. Internally, the hemolymph of Porcellio scaber do not contain blood cells, so the gills intake oxygen which is then dissolved in the blood fluid or binds to hemocyanin, where it stores the oxygen for when it is needed. Furthermore, in order for this gas exchange to occur, the gills of the Porcellio scaber must be covered with a thin layer of moisture (Jackman). Overall, with these biology factors in mind, a change in light intensities, moisture, and temperature might affect its behavior. The purpose of our experiments was to observe the effects of each variable to twenty Porcellio scabers.