# Pacific american school high school chemistry lab report now what do i do

Post on 21-Aug-2015

193 views

Category:

## Education

0 download

TRANSCRIPT

1. 1. Pacific American School High School ChemistryNow What Do I DoKyle Teng Grade 10 October 12th, 2012
2. 2. Laboratory BackgroundMember List:lLab Instructor: June ZhanglLab Leader: Kyle TenglLab Members: Kyle Teng, Jackie Jao, Jack Hsiao, Alex Chen
3. 3. Introduction:The purpose of this lab is to let student experience and understand the actual labanalytical Chemist participate. In this lab we will solve problems by making accuratemeasurements and applying mathematics.Materials: lPlastic Cup lBalance lCalculator lWater lPen & Pencil lPaper lPenny before 1982 lPenny after 1982 lSmall-scale pipet lAluminum canMethods:Step 1:Measure the mass of the plastic cup by balance.Step 2:Add 50 drops of water form the small-scale pipet in 50-degree angle to oneof the plastic cup and then measure it mass by balance.Step 3:Add 50 drops of water from the small-scale pipet in 45-degree angle to oneof the plastic sup and then measure it mass by balance.Step 4:Add 50 drops of water from the small-scale pipet in 0-degree angle to oneof the plastic sup and then measure it mass by balance.Step 5:Use information that we found form the lab and experiment above tocalculate and came out an answer for the best degree for doping water.Step 6:Use a balance to Measure the mass of the penny before 1982
4. 4. Step 7:Use a balance to Measure the mass of the penny after 1982Step 8:Use information that we found form the lab and experiment above to calculate and came out an answer of which one lighter between penny before 1982 and penny before 1982.Step 9:Use a balance to measure the mass of the aluminum canStep 10: Used density formula to find the volume of the aluminum canData:Which is the Best Degree for Dropping Water?Trial 1:Degree angles while Mass of Plastic Cup (g)After 50 drops of water/dropping the Mass of the Cup (g)9014.6616.644514.6216.380 14.6216.84Trial 2:Degree angles while Mass of Plastic Cup (g)After 50 drops of water/dropping the Mass of the Cup (g)9014.6616.824514.6616.680 14.6616.86Trial 3:Degree angles while Mass of Plastic Cup (g)After 50 drops of water/dropping the Mass of the Cup (g)9014.6616.544514.6816.800 14.6416.98
5. 5. Mass of CoinsCoins before 1982Coins after 19823.12g2.58gAluminum CanMass of the aluminum can 5.6gDensity of aluminum can2.70g/cm3Results: In the experience what is the best degree for dropping water? trial 1, trial 2,and trial 3 data shows the degree angle while dropping at the fist range, the mass ofplastic at second, and the mass of the plastic cup after 50 drops of water has beendropped at third. In the experience mass of coin the data shows the mass of coins before 1982 atthe first range and the mass of the coin after 1982 at the second. Coins after 1982 arelighter Coin before 1982. In the experience aluminum can the data show the mass of the aluminum canwhich will later come out with volume, form the density formula.Discussion and Analysis: In the experience What is the Best Degree for Dropping Water? we need to getthe mass of water to find the amount. The greater mass the more amounts, the moreamount the better. To find the mass we need to subtract the mass of the plastic cup after 50 drops ofwater to the mass of the empty plastic cup and then average it.Trail 1: 90 degree, 16.64g 14.66g = 1.98g 45 degree, 16.38g 14.62g = 1.79g 0 degree, 16.84g 14.62g = 2.22g
6. 6. Trail 2: 90 degree, 16.82g 14.66g = 2.16g 45 degree, 16.68g 14.66g = 2.02g 0 degree, 16.86g 14.66g = 2.20gTrail 3: 90 degree, 16.54g 14.66g = 1.86g 45 degree, 16.80g 14.68g = 2.12g 0 degree, 16.98g 14.64g = 2.34gAverage mass of 50 drops: 90 degree, (1.98g + 2.16g + 1.86g) / 3 = 2.00g 45 degree, (1.79g + 2.02g + 2.12g) / 3 = 1.98g 0 degree, (2.22g + 2.20g + 2.34g) / 3 = 2.25gAverage mass of 1 drop (1g = 1000mg): 90 degree, 2.00g / 50 = 0.04 = 40mg 45 degree, 1.98g / 50 = 0.0396 = 39.6mg 0 degree, 2.25g / 50 = 0.045 = 45mgAverage mass of all in one drop: (40mg + 39.6mg + 45mg) / 3 = 41.5mgAverage volume of all in one drop (1000ul = 1ml): Density = Mass / Volume Density of water = 1.00g/ cm3 = 1000mg/ cm3 = 1000mg/ ml 1000mg/ cm3 = 41.5mg / Volume Volume = 0.041.5cm3 = 0.041.5ml = 41.5ul As a result the experience show us that dropping water form 0 degree is the best,then 90 degree and 45 degree is the worst. To proof the result, we can see the numberafter the calculation shows dropping from 90 degree angle in Trial 1 is more then thedropping from 45 degree angle, but less then 0 degree angle, in Trial 2 is more thendropping from 45 degree angle, but less then 0 degree, in Trial 3 is more then
7. 7. dropping from 45 degree angle, but less then 0 degree.(The result of this experiment seems little weird, because 90 degree angle should bethe one that drop the most, then 45 degree angle, and 0 degree angle the least. Not 0degree the most, then 90 degree, and 45 degree the least. One of the reasons that causethis problem is the inconstant amount of water per drop, which night lowers theaccuracy of the experiment.) In the experience mass of coins we need to determine which coin are lighter,Coin before 1982 or Coin after 1982. The reason why these two coins have differentmass is because these two coins contains different amount of copper and zinc.Pennies made before 1982 contains 95.0% copper and 5.0% zinc. Mass of Copper: 3.12g 95.0% = 2.964 Mass of Zinc: 3.12g 5.0% = 0.156Pennies made after 1982 contains 2.4% copper and 97.6% zinc. Mass of Copper: 2.58g 2.4% = 0.06g Mass of Zinc: 2.58g 97.6% = 2.52g In the experience aluminum can we need to find its volume form the densityformula with its mass.Density formula:Density = Mass / Volume 27.0g/ cm3 = 5.6g / Volume Volume of the aluminum can = 0.207g/ cm3Conclusions: The Purpose of these experiments above is tried to act like an analytical chemist.We provide accurate measurement and mathematic calculations. Although, there aresome result seems weird in the experiment, most of then are successful and well done.
8. 8. Figures and Graphs:Water Drops by Angle 2.34 2.25 2.22 2.2 2.16 1.98 2 2.02 2.12 1.86 1.98 1.79 Trail 1 (g) Trail 2 (g) Trail 3 (g) Average (g) 90 Degree 1.98 2.16 1.86 2 45 Degree 1.79 2.02 2.12 1.98 0 Degree 2.22 2.2 2.34 2.25 90 Degree 45 Degree 0 Degree Material for Coins Before and After 1982 Coin Before 1982 Coin After 1982 0.00% 20.00% 40.00% 60.00% 80.00% 100.00% 120.00% Copper Zinc References:Wilbraham, Staley, Matta, Waterman. Prentice Hall Chemistry. Pearson plc:London, n.d. Print.