Results And Conclusions Essay, Research Paper

Results and Conclusions:

Part 1

Closing the ports changed the color of the flame. Depending on the color of the flame is the combustion. When the flame was orange is had incomplete combustion, when the ports were closed and the flame turned blue, it had complete combustion which is wanted. Turning the needle valve at the bottom of the burner adjusted its height. A lower flame was needed more because it was more controlled and easier to work with, and using the needle valve accomplished this. When burning the evaporation dish, if an orange flame was used, the dish turned black because o incomplete combustion. Because carbon is produced from a yellow or orange flame, the bottom of the dish turned black. The copper wire, when held in the flame, changed color. If it was held at the very tip of the blue cone, it turned bright red in heat. The best flame therefore, was a flame that had a blue cone in the center bottom.

Part 2

The best way to cut the glass used in Glass Manipulations is by sawing it harshly in the same place with a file. By cutting into the glass and making a ridge with the file, it became easier to break. When fire polishing the glass, it turned its harsh edges into smooth rounder ones. The fire melted the sharp ends into smooth workable ones. When the glass was being bent it was easier to maneuver in the heat of the flame. The flame made the glass weaker and therefore more flexible The lubricant was used to insert the glass tubing, making the insertion easier and less of a hassle. Because the lubricant was used, the glass slide in more comfortable, and the worry of it snapping was reduced.

Part 3

The slick surface of the glazed paper is preferred over regular paper. Chemicals slide easily off this paper, so when the salt was poured into the funnel, the glazed paper provided a slicker surface, allowing the salt to slide down it.

Part 4

Chemicals are never allowed to touch the surface of the balance pan, therefore a weighing dish or paper had to be used underneath it. When using an electronic balance, the balance should first read 0.00 meaning there are to be 2 decimal places. The two decimal places are used for more accurate readings of mass of the paper, and the salt. The mass of the paper was 0.23 when weighed alone before the salt. After adding the salt onto the paper the amount was 1.26. The function of the tare button is to be pressed after the paper has been weighed, that way when the salt has been weighed the balance will automatically subtract the weight of the paper from the salt, to find the total sum.

Part 5

The volume of each of the different pieces of equipment was different, therefore each piece of equipment should be used when measuring different amounts of liquid. The graduated cylinder holds 100 mL of liquid, the pipet holds 5 mL, and the buret holds 50 mL. All of them are fairly accurate, but depend on different degrees of measurement. The graduated cylinder?s scale was 1 mL, the pipet?s is 0.1 mL and the buret is also 0.1 mL. The most accurate way to read it would be by looking at the bottom of the curve. The meniscus, being the curved surface, is read depending on whether or not the liquid wets the glass. The meniscus should be read at the bottom of the concave. The 3 pieces of equipment, the graduated cylinder, the pipet and the buret, are different in that the g. c. is used for approximate measurements and the pipet and buret are used for more accurate volume measurements. The pipet bulb is used to suck the liquid up, not mouths. When squeezed ahead of being but in the water and released in the water it sucks up the liquid and it remains there after the bulb has been released. To release the water take the pipet out from the water. All of the bulbs actions revolved around suction and pressure. The stopcock was more of a pain to use because it is more involved. The stopcock worked by turned the nozzle to release the liquid from the buret, it was harder to control the amount of liquid being released.

Part 6

The substance that was used which is salt, water, and sand, were all put together in this experiment. Because they all were separate substances put together it was a physical change. The properties of the substance changed, but remained the same chemical, only in a different form. The content that was filtered out of the water was the sand. Salt is soluble so it went through the filter paper down with the water. Because sand is insoluble in water it was filtered out. The function of the filter paper was to keep the insoluble substances out of the container, and let the soluble ones through. The salt spat when it built up too much, to reduce this put a watch glass on top of it.