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You want to determine the percent of sulfate in an unknown sample of a hydrated metal sulfate with the formula My(SO4)x·nH2O. You dissolve 0.2888 g of your unknown in DI water and heat to near boiling. You react the dissolved unknown with a hot barium chloride solution and you collect the barium sulfate you make via gravity filtration. The filter paper weighed 0.597 g after a piece was torn off. The dry barium sulfate crystal and the filter paper weighed 0.910 g. Answer the following:

1. What is the molar mass of barium sulfate?

2. What is the molar mass of sulfate?

3. How many moles of sulfate were produced?

4. How many grams of sulfate were produced?

5. What is the percent sulfate?

I know the answer for the first two but im unsure of the next couple of questions. Thank you in advnadce :)

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Beverley Smith
Beverley SmithLv2
17 Dec 2019

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Related questions

Organic chemistry question about extraction lab...?
Procedure:
Place 2.0 g of the mixture of sucrose, acetylsalicylic acid and acetanilide into a 125 mL Erlenmeyer flask.
Add 50 mL of methylene chloride (dichloromethane) and dissolve as much of the solid as possible.
Remove the insoluble sucrose via gravity filtration using fluted filter paper. Allow to dry until the next lab period.
Add the methylene chloride solution to the separatory funnel and extract it with two 25 mL portions of 5 % sodium bicarbonate (aqueous).
Place the combined aqueous layers into a 400 mL beaker and add enough concentrated hydrochloric acid to make it very acidic (less than pH of 2) – approximately 10 mL
Allow the solid to crystallize from the aqueous layer. Chilling in an ice bath may be required.
When lots of solid has been formed, collect the solid by vacuum filtration. Wash the solid with approximately 5 mL of cold water
Allow the solid to dry open until the next lab period.
Dry the organic layer (methylene chloride) over anhydrous sodium sulfate.
Decant the solvent from the drying agent (or gravity filter through fluted filter paper) into a clean, dry a pre-weighed 100 mL round-bottom flask.
Evaporate the solvent using rotary evaporation and allow the residue to dry open over the week.
The following lab period, weigh all 3 solids, take the melting points of all 3 solids and calculate the percent composition of the original solid.

Drying agents:
Equations for drying agents:
MgSO4 (s) + 7 H2O(l) ïƒ MgSO4.7H2O(s)
CaSO4(s) + 2 H2O(l) ïƒ CaSO4.2H2O(s)
CaCl2(s) + 6 H2O(l) ïƒ CaCl2.6H2O(s)
Na2SO4(s) + 7 H2O(l) ïƒ Na2SO4.7H2O(s)

1. The original organic solution was extracted two times with aqueous sodium bicarbonate. After the extraction, what compound(s) were in the organic layer? What compound(s) were in the aqueous layer?

________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. Assume that both acetylsalicylic acid and acetanilide are soluble in diethyl ether, and that diethyl ether was used in place of the methylene chloride. Would the ether layer be the bottom layer in the separatory funnel or the top layer? Explain your answer.

________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Assume that both acetylsalicylic acid and acetanilide are soluble in methanol, and that methanol was used in place of the methylene chloride. What problem(s) might occur during the extractions? (Careful, this is a trick question.)

________________________________________________________________________________________________________________________________________________________________________________________________________________________

4. Historically, the solid residue that is left after the methylene chloride solution is evaporated has a lower melting point that its literature value, due to impurities. Explain what impurities are present and why.

________________________________________________________________________________________________________________________________________________________________________________________________________________________

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.

ACYLATION OF AN AROMATIC AMINE

Prepare a solution of 2.5 g of p-toluidine, 65 mL of water, and2.5 mL of concentrated

hydrochloric acid in a 125 mL Erlenmeyer flask. Be sure to placethe reagents in the flask in that

order! Using a warm hot plate to assist you, swirl the contentsof the flask until all of the solid

dissolves. The purpose of the acid is to protonate thep-toluidine and increases its solubility in

water.

In a small beaker, dissolve 3.75 g of sodium acetate trihydratein 7 mL of water. Again,

use a warm hot plate to speed up the process, if necessary. Thepurpose of the sodium acetate is

to buffer the solution. We want the pH such that the carbonylgroup is electrophilic but some of

the amine group is not protonated. A protonated carbonyl groupis more susceptible to

nucleophilic attack, while the amino group can only act as anucleophile when it is not

protonated.

Heat the p-toluidine hydrochloride solution to 50 ?C using a hotplate. While stirring or

swirling rapidly, add 2.5 mL of acetic anhydride from a burettein the hood. Then add the

sodium acetate solution prepared above. Once the solution isthoroughly mixed, cool the flask in

an ice-water bath. A white precipitate should form. Collect thissolid via vacuum filtration.

While the solid is on the filter paper, wash it three times withcold water. After washing the

solid, remove as much of the water from the product by suctionfiltration as possible. Once the

product is fully dry, determine the mass, measure the meltingpoint and calculate the percent

yield. Let your Teaching Assistant evaluate your product anddispose of it properly


please please please please help me do allthese:


calculate the limiting reagent and

the theoretical yield

and the chemical balanced equation



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