The Terms

August 23, 2009

Lab Partner-Joey Stabel

The Analysis of Alum

K.Schuyler

Elvir Malikic

Purpose

Determining and understanding the characteristics of Aluminum

Pre-Lab questions

1) When conclusion a melting point, why is it necessary to raise the temperature very(prenominal) late when approaching the melting temperature? When raising the temperature very slowly it gives the thermometer time to display the accurate temperature of the substance giving you a more accurate reading. Another reason would be the visual of things changing in a slower giving you time to examine whats happening.

2) Washing soda is a render compound whose formula can be written Na2CO3·X H2O, where X is the topic of moles of H2O per mole of Na2CO3. When a 2.123 g sample of washing soda is heated at one hundred thirty°C, solely of the water of hydration is lost leaving 0.789 g of anhydrous sodium carbonate. Calculate the value of X.

a. 2.123gWashing Soda - 0.787gNa2CO3 = 1.336g H2O

b. 1.336gH2O/0.787gNa2CO3= 1.68

c. (1.68) x (106gNa2CO3/1molNa2CO3)=179.135

d. (179.135) x (1molH2O/18gH2O)= 9.95

e. 9.95=X

3) The formula for epsom salts is MgSO4 7H2O. IF there is 1.



250 g of the compound is disolved in water,calculate the number of milliliters of .200 M Ba(NO3)2 which would be required to just precipitate all o fthe sulfate as barium sulfate.

a. MgSO4+Ba(NO3)2 ---> BaSO4+ Mg(NO3)2

b. Molar hatful of MgSO4,7H2O is 246

c. 1.25/246 =0.0051moles

d. 1 mL solution there is 0.2mM of Ba(NO3)2

e. 5.1/0.2 =25.5 mL

3) B

1.00f ALK(SO4)2x12H2O(1mole)(2mSO4) / (474grams) = .0042mBa

(.0042mBa)(1m Ba(NO3))(1Liter)(1000ml) / (1m Ba)(.2mBa(NO3)2)= 21.1moles of...If you want to present a full essay, order it on our website: Ordercustompaper.com



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