Log in
Chemistry
1
answer
0
watching
240
views

Part I: What is the complete formula (Salt · x H2O) for the hydrate you will be given in lab?

(25 points)

 

General Procedural guidelines for this lab:

 

  1. From the very beginning of this experiment, only handle the crucible or evaporating dish with crucible tongs. SAFETY: The crucible will be very hot! Never touch the crucible while it could be hot. Use crucible tongs.
  2. Use the same scale throughout this lab.
  3. Do all of your calculations with proper sig figs.
  4. For additions and subtractions, keep the fewest number of decimal places.
  5. For multiplication and division keep the fewest number of significant figures.
  6. While things are heating and cooling, work on Part II of this task.

 

 

Procedure: Watch this video, read along with the following procedure, and take notes: https://www.youtube.com/watch?v=k2s-YG15eIA

 

  1. Wash out a crucible and flame dry. Heat the crucible with a Bunsen burner for 5 minutes on high and let it cool for 10 minutes.

 

  1. Zero the balance.

  2. Mass the crucible and record the mass (with units). __________

 

  1. Fill the crucible about ¾ full with the hydrate.

 

  1. Mass the crucible with the hydrate and record this mass. __________

    Record the color of the hydrate (before heating). __________

 

  1. Heat the crucible with the until all water is driven off. What is left in the crucible is the anhydrate.

    Record the color of the anhydrate (after heating). __________

 

  1. Let the crucible cool for a few minutes (at least 10). Then mass the anhydrate and crucible and

    record this mass. __________

 

  1. Complete the calculations to determine the (i) % mass of water in the hydrate and (ii) the value for x for your hydrate. Show all of your calculations. The calculations for the % mass of water in the hydrate are outlined in the video. You will have to do the calculations for x by yourself. Show all of your calculations on this page or another page.

 

MAKE A DATA TABLE HERE FOR ALL OF YOUR DATA:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MAKE A RESULTS TABLE HERE FOR THE RESULTS OF YOUR CALCULATIONS:

 

Watch
1
answer
0
watching
240
views

For unlimited access to Homework Help, a Homework+ subscription is required.

Christian Tuso
Christian TusoLv10
21 Jan 2021

Unlock all answers

Get 1 free homework help answer.
Already have an account? Log in
Share
discord banner image
Join us on Discord
Chemistry Study Group
Join now

Related textbook solutions

Basic Chemistry
5 Edition,
Timberlake
ISBN: 9780134138046
Principles of Chemistry Molecular Approach
4th Edition,
Tro
ISBN: 9780134112831
Principles of Chemistry Molecular Approach
3rd Edition, 2014
Tro
ISBN: 9780321971944
Chemistry: Structure and Properties
2nd Edition,
Tro
ISBN: 9780134293936
Chemistry: A Molecular Approach
3rd Edition,
Tro
ISBN: 9780321809247
Chemistry: A Molecular Approach
5th Edition,
Tro
ISBN: 9780134874371
Principles of Chemistry: A Molecular Approach
4th Edition,
Tro
ISBN: 9780134895741
Chemistry: The Central Science
14th Edition, 2017
Brown
ISBN: 9780134414232

Related questions

Questions are in the data analysis and this is my data

3. After setting up we measured the crucible to weigh 31.353 grams

4. next we measure the mass of the copper chloride hydrate mass using the weigh paper. It came out with a mass of 1.045grams.

Next we put the copper chloride in the crucible

After that we measured them all together and it weighed 32.4 grams.

5. We put the crucible on the clay triangle and did not tilt the lid be cause lab instructor told us not to

6. Next we sparked the flame to the Bunsen burner

7. Now with the Bunsen burner lit we are ready to observe. As the substance started to heat it up it started slowly to turn greenish and then was slowly turning brown. It is turning brown from the outside walls of the substance to the inside. After all the heating it slowly turned a little light brown, but brown.

8. Once heating is completed, turn off the equipment and allow the sample to cool.

a. Turn off the Bunsen burner.

b. Use a pair of crucible tongs to place the crucible on a wire mesh screen on the

bench.

c. With the tongs, move the lid so that it covers the crucible bottom completely.

Allow the sample to cool for about ten minutes.

9. Remove the crucible cover and carefully inspect the sample. If any of the sample has

maintained its initial appearance, reheat the sample until all of it has reacted.

10. After we allowed the sample to cool we then measured it and it had a mass of 32.222 g

11. next we are adding the deionized water to the cooled dried sample. We rinsed out the crucible and added it to the beaker with around a total of 16mL of DI water. Once initially added it was green on the bottom with precipitate was left on the bottom and blue on the top. After we stirred it now it is light blue and clear. It is just really light blue now and clear.

12. we obtained a piece of aluminum wire we coiled it and stirred it. Its turning from blue to greyish color and its fizzing and it getting warmer. After a little bit there is now copper on the bottom of the beaker. They are redish color and the solution on top is also a redish color.

13. we obtained 10mL of 6 M HCl solution. Next we dropped them in and the solution is fizzing again.

14. we put the filter paper on the filter paper and are now filtering the substance.

15. mass of dry watch glass 39.025 grams

16. 39.278 grams and second time was 39.274


Part 1: Separation of Iron filings

  1. Mass a watchglass and record
  2. Obtain a Kimwipe tissue from the top of the benches and a rodmagnet
  3. Wrap the Kimwipe tissue around the magnetic end, holding thetissue tight to the rod magnet.
  4. Swirl the Kimwipe in your mixture. Knock off excess sand beforemoving on to step 5
  5. Carefully over the watch glass remove the Kimwipe tissue fromthe magnet so the iron falls on the the watch glass
  6. Repeat steps 4 and 5 two more times, make sure you record howsuccessful this separation was � does the evaporating dish containonly iron?
  7. Mass the watchglass and the collected iron.
  8. Dispose of the iron in the hood.

Part 2: Separation of N

  1. Mass a clean, dry, evaporating dish.
  2. Pour the leftover mixture from step 1 into the evaporating dishand mass.
  3. Place the evaporating dish on a hot plate in the hood.
  4. Gently and slowly heat the mixture until the white fumes cease.Be patient. Depending on the amount of ammonium chloride in yoursample, this could take quite a while. A half our would not beunheard of.
  5. Stir the mixture frequently to facilitate the sublimation ofthe ammonium chloride. This is crucial in order to obtain goodresults. (Use crucible tongs to hold onto the dish so it doesn�tmove as much)
  6. After the white fumes disappear, turn off the hot plate andremove the evaporating dish with crucible tongs and let it cool inthe hood.
  7. When the evaporating dish is cooled, mass the left overmaterial and the evaporating dish.

Part 3: Determining the amount of NaCl.

  1. Measure 10 mL of distilled water in a graduated cylinder.Slowly add the water to the mixture in the evaporating dish whilecontinuously stirring with a clean, glass stirring rod. Afteradding all of the water, stir for 2 min more.
  2. Assemble the gravity filtration apparatus shown in Figure1.
  3. Fold a piece of filter paper as shown in Figure 2. Open up thepaper cone, and place it in the filtering funnel.
  1. Position a beaker under the funnel, making sure that the funnelstem is touching the inside wall of the beaker. Pour as much of thesupernatant liquid as possible from the evaporating dish intofunnel. Collect the filtrate in the beaker.
  2. Transfer the solid remaining in the evaporating dish into thefunnel, using a stream of distilled water from a wash bottle, asshown in Figure 3.
  3. Re mass the watchglass from Part 1 and record this mass.
  4. Pour the filtrate in the beaker into the evaporating dish
  5. Place the evaporating dish containing the filtrate on a hotplate. Begin heating the solution.
  6. While the solution is heating to boiling, move onto Part 4
  1. Carefully remove the filter paper and residue from the funnel.Place the paper and residue onto the watchglass.
  2. Place the watchglass with the filter paper and sand on top ofthe boiling salt solution to dry the sand
  3. Keep the salt water boiling, until there is just a little bitof water left, or popping sounds are heard, then turn off the hotplate, and allow the heat from the hot plate to finish evaporatingand drying your salt.
  4. Allow the evaporating dish and its contents to cool to roomtemperature.
  5. Obtain another watch glass and mass.
  6. Transfer the dried sand and filter paper from original watchglass (caution, salt has spattered onto this watch glass, so don�tknock any off, that is product you will need) onto the new cleanmassed watch glass. Replace the original watch glass onto thecooling evaporation dish
  7. Mass the new watch glass, sand and filter paper all together.Discard filter paper and sand into garbage. Observe how pure yoursand looks.
  8. After evaporating dish has cooled, determine the mass of theevaporating dish, watch glass plus NaCl. Record this mass. Then,discard the NaCl as directed. Wash evaporating dish and watch glassto dissolve the salt.
  9. Observe how pure your salt looks.

Result and Discussion: Separation Lab

Substance

Grams recovered

% mass

Fe

NH4Cl

NaCl

SIO2

Overall percentRecovery:

A) Explain what steps(s) youcould have improved (and how) to help your percentrecovery.

b) Write a paragraph about thelab include briefly what was done, your result, were you correctand possible experimental errors- do not state human measurementerrors as errors. Be Specific, what specific human errors occurred,what measurement errors occurred, what process in the experimentcould errors have occurred.

Weekly leaderboard

Home
Homework Help 3,900,000
Chemistry 830,000
Start filling in the gaps now
Log in