Friday, 3 August 2012

.10. Assignments of Solution



ASSIGNMENT #1

1.     What is the molarity of HNO3 in concentrated nitric acid , a solution with a density of 1.42g /cm3 that contains 68.0% HNO3 by mass?

2.     The antifreeze in most automobile radiators is a mixture of equal  volumes of ethylene glycol and water with minor amount of other additives that prevent corrosion . What is the molarity of ethylene glycol in a solution prepared from 2218 g of ethylene glycol and 1996 g of water

3.     At 25 0C   ,25 g of glycine the simplest amino acid found in proteins, will dissolve in exactly 100 g of water .Calculate the mole fraction of glycine and water in solution.

4.     Calculate the mole fraction of solute and solvent in a 3.00 molal solution of sodium chloride .

5.     A sulphuric acid solution containing 2.001 g of sulphuric acid in 0.350 liter of solution at 20 0C has density of 1.3294 g/ml . Calculate (a) the molarity , (b) the molality, (c) the percent by mass of Sulphuric acid and (d) the mole fraction of sulphuric acid .

6.     Assume the solution is the ideal and determine the vapour pressure of a solution of 92.1 g of glycerin in 184.4 g of ethanol at 40 oC . The vapour pressure of pure ethanol is 0.178 atm  at 40 oC. The glycerin is essentially non volatile at  this temperature

7.     Find the Freezing point  of a solution  of 92.1 g of iodine , in 800g of Chloroform, assuming that the iodine nonvolatile at that the solution is an ideal. Kf  of chloroform is 4.68 oC/mol/kg an freezing point is -63.5 oC
      
8.     Find the boiling point  of a solution  of 92.1 g of iodine , in 800g of Chloroform, assuming that the iodine nonvolatile at that the solution is an ideal. Kb  of chloroform is 3.63 oC/mol/kg an Boiling  point is 61.26 oC       
     
Reference : Table 12.1 of General Chemistry
By Robinson-Odom-Holtzclaw(10th Edition)
Solvent
Boiling point(oC)
k 
oC. mol.kg-1
Freezing point 
k 
oC mol.kg-1
Water
100.00
0.512
0.00
1.86
Acetic Acid
118.1
3.07
16.6
3.9
Benzene
80.1
2.53
5.5
5.12
Chloroform
61.26
3.63
-63.5
4.68
Nitrobenzene
210.9
5.24
5.67
8.1









ASSIGNMENT #2

Topoic:  Percent, ppm and ppb

1) Calculate the concentration of salt in a solution of water in percent if 45 grams is dissolved in 1,200 ml of water.
2) Calculate the mass of solute in a 10% salt solution if the mass of the solvent is 350 grams.
3) Calculate the mass of solvent in a 6 ppm solution of a drug if the mass of the solute is 0.050 milligrams.
4) What is the concentration in ppm of selenium if 1.3 milligrams is found in 2,500 kg of soil?
5) What is the concentration in ppb of PCB's in a chemical spill, if their is 0.060 mg in 4,600 Kg of soil?
6) Calculate the mass of solute of hydrogen peroxide in a 35 % solution if 450 ml of solution is being used.
7) Calculate the mass of solute PCB's in a 65 Kg person, if the concentration is 4 PPM?
8) What mass of nickel is in a 2.4 Kg sample of propanol if the concentration is 20 ppb?
9) Calculate the mass of solvent that would contain 3.0 mg of a drug if the concentration was 3.5%.
10) Calculate the concentration in ppm if 8 grams of CaClis dissolved in 250 ml of water.

No comments:

Post a Comment