Friday, March 9, 2012

Silver and Copper Lab

Silver

Copper

 Replacement

  Lab


- Soooooo I was gone for majority of this lab, but hey! I'm going to try my best thanks to some help my friend Serena!

Materials:
-Silver Nitrate
-Copper
-Distilled Water
-Test Tube
-Filter Paper
-Funnel
-Beaker

Procedure for Day #1:

Step 1-Obtain 30cm of bare copper wire. Clean the wire, then coil it around a pencil to form a loose spring. Make sure that the other end of the wire reaches the top of your test tube and is uncoiled.



Step 2-Weight the coil with a balance, then place the copper wire in the test tube to check that is is the correct length. Remove the coil and set it aside for later.


Step 3-Weight the weighing dish of silver nitrate and record it's number.


Step 4-Transfer the contents of silver nitrate to your test tube.


Step 5-Pour distilled water into your test tube until the water is about 2 cm from the top.


Step 6-Cover the top of the test tube with parafilm.


Step 7-Place your thumb on top of the test tube and invert it until all the silver nitrate is disolved.


Step 8-Weigh the empty weighing dish so that you can determine the mas of silver nitrate that was added to the test tube.


Step 9-Add the copper coil to the test tube.


Step 10-Set the tube aside until the next day or class period.


Step 11-Make sure you record all data!

Procedure for Day 2!! (I was here for this part!)

Step 1- Weigh a piece of fiter paper for use in separating the silver.



Step 2- Shake the test tube and copper wire to dislodge the silver.








Step 3- Set up a funnel with your filter paper in it.


Step 4- With a waste beaker beneath the funnel, lift the copper wire out of the test tube and hold it over the filter system.


Step 5- Using a water bottle, let distilled water run down the wire so that any silver will wash into the filter.


Step 6- Lay the copper wire on a labeled piece of paper to allow it to dry.


Step 7- Pour off the solution in the test tube through the filter paper into the filter, trying to keep the silver precipitate in the test tube.


Step 8- Rinse with distilled water and decant several times into the filter to wash the silver.


Step 9- Finally wash the silver from the test tube onto the filter paper.


Step 10- Allow to dry overnight.





Procedure for Day 3!!

Step 1- Weigh the copper coil and record it's mass.



Step 2- Weigh the silver and filter paper - record the mass.

Numbers, Numbers, Numbers!!! Data, Data, Data!!!! Conclusion, Conclusion, Conclusion!!!!!

Silver Nitrate's Mass: 1.369 grams
Mass of the Copper Coil Before: 3.68 grams
Mass of the Copper Coil After: 3.26 grams
Mass of Copper Reaction: .423 grams
Filter Paper Mass: 1.389 grams
Filter Paper & Silver: 1.892 grams
Mass of Silver Produced From Reaction: .503 grams
Silver Production in MOLES!: .0032 moles
Copper Consumtion: .0036 moles

EQUATION TIME AGAIN!
2AgNO3 + Cu --> Cu(No3)2 + 2Ag

Evaporation and Intermolecular Attractions

Lets Begin!!!
Evaporation and Intermolecular Attractions
Yes that's ATTRACTION not Reaction! It's time to get down to the relationship status!

1st Come the Materials:

  • Computer (DUH! OBVIOUSLY!)
  • Serial Box Interface ULI
  • Data Logger
  • Two Probes
  • 6 Pieces of Filter Paper
  • 2 Small Rubber Bands
  • Methanol ( Methyl Alcohol)
  • Ethanol (Ethyl Alchohol)
  • 1-Propanol
  • 1-Butanol
  • n-Hexane
  • n-Pentane
Procedure, Procedure, Procedure! This Is What it Comes Down TO!:
  1. Open "Experiment 9" from the Chemistry with Computers from the experiment files of Logger Pro.
  2. Wrap filter paper around the tips of probes 1 and 2, and secure them with the rubber bands. By the way this was the hardest part!!!!
  3. Place both probes into a container holding a sample of either methanol or ethanol.
  4. After the probes have been in the liquids for around 30 seconds, begin data collection. Monitor the temperature for around 15 seconds to establish the initial temperature of each liquid.
  5. Simultaneously remove the probes from the liquids and tape them with the tips of the probes extended of the edge of the counter.
  6. When both temperatures have reached minimums, stop data collection, it kinda stops itself...
  7. Find the maximum and minimum temperatures, then subtract them to find the change of temperature during evaporation.
  8. Remove the rubber bands and discard the used filter paper.
  9. Predict, using the data just collected, how the next set of substances will react!
  10. Repeat these steps for the final substances as well!! :)
Data Analysis:
  1.  Most of these substances contain hydrogens bonds which is very apparent for 1-Butanol and n-pentane. Their overall weights were very similar, however the temperature change between the two was vastlly different. Can you say hydrogen bonds were the cause! Definitely! 1-Butanol contains hydrogen bonds, but n-pentane does not. This made it easier for n-pentane to evaporate compared to 1-Butanol.
  2. Methanol had the weakest intermolecular forces out of the six tested. However, 1-Butanol had the strongest. We can see that methanol had the weakest bonds because of the change of temperature. Methanol changed 17.38 degrees. This shows that it had weak bonds, allowing it to evaporate more quickly than the other liquids. 1-Butanol had the strongest bonds because its temperature had a low change rate. It's temperature only went down by about 2.41 degrees. This means that it had stronger intermolecular forces which didn't allow it to evaporate as much or as quickly as methanol. So basically the lower the change the better and the stronger intermolecular force the substance has!
  3. Alkanes! n-Hexane had the weakest intermolecular forces, and n-pentane had the strongest molecular forces. n-Hexane changed a total of 10.00 degrees, and n-pentane only changed 7.28 degrees.

Green-Ethanol & Red-Methanol



Red- 1-Propanol & Green- 1-Butanol


Red- n-Pentane & Green- n-Hexane

Thursday, March 8, 2012

Dry Lab

A dry lab?  Doesn't that just make you think the ingredients or materials are dry? well thats what i thought until Mr. Ludwig explained that this lab was actually very serious and dangerous and we would not actuallly be performing the procedure. In this lab we would simply be following what others have already done, and simply analyzing the conclusion and results.

PROCEDURE TIME!!!!
  1. Clean and dry two beakers
  2. Record the number of you chemical- Lab #5 ( I had either 4 or 5 I cant really remember which! Sorrys!)
  3. Find the mass of lead(II) nitrate- 1.03 grams
  4. Find the mass of potassium iodide- 1.33 grams
  5. Add about 50mL of DI water to each beaker
  6. Stir the beakers until both chemicals have dissolved
  7. Combine the contents of both beakers into one beaker
  8. Wash any remaining solution into the one beaker
  9. Stir the solution
  10. Measure the mass of filter paper- 1.39 grams
  11. Filter out the precipitate into the filter paper
  12. Wash any remaining precipitate into the filter paper 
  13. Allow the precipitate and filter paper to dry overnight
  14. Find the mass of the precipitate- .95 grams
QUESTION TIME!!!

Question: What is the balanced equation for the chemical reaction that occured in the experiment?
Answer: The balanced equation for this particular chemical reaction is: 2KI + Pb(NO3)2 --> 2KNO3 + PbI2 (Thank goodness for notes! I'm so slow at balancing equations!)

Question: What was the limiting reagent for your experiment?
Answer: The limiting reagent for this experiment was: Lead (II) Nitrate

Question: How much lead (II) Iodide will theoretically be formed?
Answer: Theoretically speaking there should be: 1.43 grams of lead(II) iodide formed from the experiment

Question: How much lead (II) iodide did you get from your experiment?
Answer: However when i performed the experiment there was actually: .96 grams of lead(II) iodide formed from the experiment

Question: What was the Percent yeild for your experiment?
Answer: The percent yield of lead(II) from the experiment was: 67%