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					                     Faculty of Engineering – Cairo University
                        Chemical Engineering Department
                      Chemistry for Biomedical Engineering
                        April-2003 Time allowed: 1 hours

        1. a) Define and write the equation relating each of the following items:
           i) A phase ii) The number of components iii) The number of degrees of
           freedom.
           b) Consider n liquids of which only K are soluble ( K< n ) No chemical
           reactions take place. Prove that under boiling conditions the number of
           degrees of freedom is K.
           c) A mixture of liquid, ice, and water vapor.

          2- a) Write balanced equations for each of the following reactions:
                1. FeS2 + O2  Fe2O3 + SO2
                2. Mg + FeCl3  MgCl2 + Fe
                3. C6H12O2 + O2  H2O + CO2
                4. CoBr3 + Na2CO3  Co2(CO3)3 + NaBr
            b) Write balanced net ionic equations for each of the following
            reactions:
           1. La2(CO3)3 (S) +HCl  LaCl3 + CO2 + H2O
           2. Ba(NO3)2 (aq) + H2SO4 (aq)  BaSO4 (S) + HNO3 (aq)

        3. a) Define the following terms and give also their units:
             1- Molality         2- Molar Concentration 3- Normality of a solution
           b) Calculate the following:
           1- Molar concentration of sulfuric acid solution of density 1.198 g/cm 3,
               containing 30 % H2SO4 by mass.
           2- The molality of the acid mentioned in (1).
           c) A 0.50-molar aqueous solution of sulfuric acid flows into a process unit
               at a rate of 1.25 m3/min. The specific gravity of solution is 1.03.
               Calculate
                    The mass concentration of H2SO4 in Kg/m3,
                    The mass flow rate of H2SO4 in Kg/s, and
                    The mass fraction of H2SO4.

           3. Sodium hypochlorite is formed according to the reaction:

                            2NaOH + Cl2 -------► NaOCl + NaCl + H2O

                 In a continuous reactor by bubbling Cl2 through a concentrated 40 %
                 mass (NaOH) solution. Suppose the solution of NaOH in H2O is fed
                 at 1000 Kg/hr and the Cl2 gas at 10 Kgmol/hr.
              Determine which is the limiting reactant?
              Calculate the outlet composition of the reactor assuming 60%
               conversion of the limiting reactant?

N.B.: atomic mass of H = 1, C = 12 , O = 16 , N =14 , S = 32, Na=23, Cl= 35.5
                   Faculty of Engineering – Cairo University
                      Chemical Engineering Department
                    Chemistry for Biomedical Engineering
                      April-2005 Time allowed: 1 hours

         1. a) What are the types of chemical reaction? Write on two
              types in details.
            b) One thousand Kilograms per hour of a mixture containing
             equal parts by mass of benzene (C6H6) and toluene (C7H8) are
             distilled. The flow rate of the overhead product stream is 488
             Kg/h, and the bottom stream contains 7.11 wt % benzene.
             Draw and label a flowchart for the process. Then calculate the
             mass and mole fractions of benzene and the molar flow rates
             of benzene and toluene (mole/h) in the overhead product
             stream.
            c) What are chemical compounds?
         2. a) Balance the equations
             5. FeS2 + O2 ---------► Fe2O3 + SO2
             6. Zn + HCl ---------►ZnCl2 + H2
             7. C7H6O2 + O2 ---------► CO2 + H2O
            b) A solution contains 10 gm acetic acid, CH3COOH, in 125
                gm water. What is the concentration of the solution
                expressed as:
                                 Mole fractions of CH3COOH and H2O
                                 Molality
        3. a) Define the following terms and give also their units:
             1- Molality       2- Molar Concentration    3- Mass fraction
           b) A solution of Caustic Soda in water contains 20% NaOH (by
              wt) at 60oC. The density of the solution is 1.196 g/cm3. Find
              the concentration of Caustic Soda in g/l. Also find the
              molarity, normality and molality of the solution.
        4. Sodium hypochlorite is formed according to the reaction:
                           2NaOH + Cl2 -------► NaOCl + NaCl + H2O
                 In a continuous reactor by bubbling Cl2 through a
                 concentrated 40 % mass (NaOH) solution. Suppose the
                 solution of NaOH in H2O is fed at 1000 Kg/hr and the Cl2
                 gas at 10 Kgmol/hr.
                Determine which is the limiting reactant?
                Calculate the outlet composition of the reactor
                 assuming 60% conversion of the limiting reactant?

N.B.: atomic mass of H = 1, C = 12 , O = 16 , N =14 , S = 32, Na=23, Cl= 35.5
             Faculty of Engineering – Cairo University
                Chemical Engineering Department
              Chemistry for Biomedical Engineering
                 May-2006 Time allowed: 1 hours

1. a) Define and write the equation relating each of the following items:
    i) A phase ii) The number of components iii) The number of degrees of
    freedom.
    b) Consider n liquids of which only K are soluble ( K< n ) No chemical
    reactions take place. Prove that under boiling conditions the number of
    degrees of freedom is K.
    c) Copper and nickel are completely soluble in the solid state. Do solid,
    liquid, and vapour phases co-exist together at one single point only?
    Why?

2. a) Write balanced equations for each of the following reactions:
           1-     FeS2 + O2  Fe2O3 + SO2
           2-     Mg + FeCl3  MgCl2 + Fe
           3-     C6H12O2 + O2  H2O + CO2
           4-     CoBr3 + Na2CO3  Co2(CO3)3 + NaBr

    b) Strawberries contain 15 % solids and water 85 % by mass. To make
    strawberry jam, crushed strawberries and sugar are mixed in a 45 : 55
    ratio, and the mixture is heated to evaporate water until the residue
    contains 1/ 3 water by mass. Draw and label a flowchart of this
    process, and use it to calculate how many Kgs of strawberries are
    needed to make 1 Kg of jam.


3. a) Define the following terms and give also their units:
     1- Molality        2- Molar Concentration 3- Normality of a solution
   b) Calculate the following:
   5- Molar concentration of sulfuric acid solution of density 1.198 g/cm3,
       containing 30 % H2SO4 by mass.
   6- The molality of the acid mentioned in (1).

   c) Calcium carbide, CaC2, reacts with water to form Ca(OH)2 and the
  flammable gas acetylene, C2H2. Which is the limiting reactant when 100.g
  of water react with 100.g of CaC2? How many grams of acetylene are
  theoretically possible? If 37.5 g of C2H2 are actually produced, what is the
  percent yield?

4. a) Define the following terms:
   1- Indicators       2- Titration      3- Ionic product of water
   b) Calculate pH of adding the following amount of NaOH (0.01M) to 100
   cm3 of benzoic acid (0.01M): 0 , 50 cm3 , 100 cm3 , 150 cm3. Then draw the
   relation between pH, Vb.
   Knowing that dissociation constant is 6.4 x 10 –05.
     5. A Cetonitrite is produced by the reaction of propylene, ammonia
      and oxygen.
           C3H6 + NH3 + 3/2 O2  C3H3N + 3H2O
             The feed contains 10 mole % propylene, 12 % ammonia, and 78
             % air. A fractional conversion of 30% of the limiting reactant is
             achieved. Determine which reactant is limiting, the percentage by
             each of the other reactant is in excess, and the molar flow rates of
             all product gas constituents for a 30 % conversion of the limiting
             reactant, tacking 100 mole of feed as a basis.
     6. Silver nitrate, AgNO3, reacts with ferric chloride, FeCl3, to give silver
      chloride, AgCl, and ferric nitrate, Fe(NO3)3. In a particular experiment, it
      was plannned to mix a solution containing 25.0 g of AgNO 3 with another
      solution containing 45.0 grams of FeCl3.
       a) Write the chemical equation for the reaction.
       b) Which reactant is the limiting reactant?
       c) What is the maximum number of moles of AgCl that could be obtained
          from this mixture?
       d) What is the maximum number of grams of AgCl that could be
          obtained?
       e) How many grams of the reactant in excess will remain after the
          reaction is over?

N.B.: atomic mass of H = 1, C = 12 , O = 16 , N =14 , S = 32,
                     Na=23, Cl= 35.5, Ca=40, Fe=56, Ag=55.8
Cairo University                                  June 2002
Faculty of Engineer                              First Year Exam
Biomedical Engineering Dept.                    Time allowed 3 hrs

                          CHEMISTRY
Question 1:                                          (25 marks)
Write detailed notes about: (Write equation whenever possible)
1- Isomerism                  2- MarkowniKoff’s rule
      3
3- Sp hybridization           4- Chloroform reaction
5- Homolysis and heterolysis 6- Aldol condensation
7- Rexnance                   8- Hardening of oil

Question 2:                                           (10 marks)
Classify amines and write equations to prepare each type.

Question 3:                                           (15 marks)
Starting from ethylene prepare the following:
1- Acetone              2- Dioxane              3- PVC
4- Gammaxane            5- Glycerol

Question 4:                                          (10 marks)
Prepare each of the following compounds industrially:
1- Methane               2- Pyrene
3- Ethylene glycol       4- Lactic acid

Question 5:                                          (15 marks)
a) Write complete and balanced equations for each of the following
reactions:
8. FeS2 + O2  Fe2O3 + SO2
9. H2SO4 + NaOH  Na x SO4 + H2O
                                Δ
10.CaCO 3  --------- + COx
11.Zn + FeCl2  ZnCl2 + Fe

b) Commercial sodium “hydrosulfite” is 90.1 % pure Na2S2O4. How
much of the commercial product could be made by using 100 metric
tons of zinc with a sufficient supply of the other reactants? The
reactions are:

                          Zn + 2 SO2     ZnS2O4
           ZnS2O4 + Na2CO3  ZnCO3 + Na2SO4
Question 6:                                       (15 marks)
a) How much carbon monoxide is produced from the reaction of 1.00
kg of octane, C3H18 , and 1.00 kg of oxygen?

b) How much potassium chloride is produced from the reaction of
2.00g of K and 3.00 g of Cl2?
Knowing that K has an atomic mass of 39 and Cl of 35.5.

c) How much 83.4 % pure salt cake (Na2SO4) could be produced
from 250 kg of 94.5 % pure salt.

Question 7:                                              (15 marks)
a) Define the following terms and give also their units:
1- Molality 2- Molar Concentration         3- Normality of a solution

b) Calculate the following:
   7- Molar concentration of sulfuric acid solution of density 1.198
      g/cm3, containing 30 % H2SO4 by mass.
   8- The molality of the acid mentioned in (1).

c) What is the molar concentration of a solution containing 20 g of
C2H5OH in 500 cm3 of solution?

Question 8:                                            (25 marks)
A) Define and write the equation relating each of the following items:
i) A phase ii) The number of components iii) The number of degrees
of freedom.
iv) Consider n liquids of which only K are soluble ( K< n ) No
chemical reactions take place. Prove that under boiling conditions
the number of degrees of freedom is K.
v) A mixture of liquid, ice, and water vapor.

B) What length of time is required to apply a metal surface of nickel
coating with an average thickness of 0.003 cm at an average density
of 40 ma / cm2, if the current efficiency is 95 %? Density of nickel is
8.9 gm / cm 3.
C) The conductance of a 0.1 m KCl was found to be 0.04006 -1 and
its specific conductivity is known to be 0.012886 -1 cm -1. Using the
same cell the measured resistance of 0.01 m acetic acid was found to
be 5.035 x 10 2 . Calculate the degree of dissociation of 0.01 m acetic
acid solution knowing that the equivalent conductivity at infinite
dilution of sodium acetate (Na Ac), hydrochloride acid (HCl) and,
sodium chloride (NaCl) are: 91 -1, 426.1 -1and,126.5 -1
respectively.

D) Knowing that a current of 5 amp flowing for exactly 30 minutes in
a ZnSO4 solution deposits 3.048 g of Zn at the cathode, Calculate the
equivalent weight of Zn.

E) Calculate Vant Hoff’s coefficient for 30 % ionization of silver
chloride solution using 5 Faradays.


   Knowing that the atomic masses of the following elements are:
   C=12    ,     H=1        ,     Cl=35.5      ,      S=32
   Zn = 65 ,     Na = 23    ,     O = 16



Cairo University                                   June 2003
Faculty of Engineer                              First Year Exam
Biomedical Engineering Dept.                 Time allowed 3 hrs

                           CHEMISTRY
Question 1:                                           (12 marks)
Write detailed notes about: (Write equation whenever possible)
  1- Sp 3 hybridization
  2- Heterolysis
  3- Resonance
  4- Vulcanization of Wbleer
Question 2: Classify:                                 (12 marks)
  1- Organic Compounds                    2- Alkadienes
  3- Dihalogen Compounds                  4- Dihydric Alcohols
Question 3:                                           (10 marks)
Write Chemical Reactions to Show:
  1- Orientation in benzene ring.
  2- Preparation of ethers.
  3- Conversion of primary to secondary and tertiary alcohols.
Question 4:
    Starting from ethylene prepares the following: (10 marks)
            1- Oxalic acid                 2- Dioxane
            3- Phorone
    Starting from acetylene prepares the following: (10 marks)
            1-Crotonaldehyde                     2- Teflon
Question 5:                                            (10 marks)
Explain (with reactions) the industrial method for preparing:
    1- Ethylene glycol                     2- Benzene
    3-Ethyl alcohol
Question 6:                                            (10 marks)
a) Write complete and balanced equations for each of the following
reactions:
           12.HClO4 + P4O10  H3PO4 + Cl2O7
           13.Fe2(SO4 )3 + BaCl2  FeCl3 + BaSO4
                                 Δ
           14.CaCO 3  --------- + COx
           15.HCl + KNO2+ CoCl2  K3Co(NO2)6 + NO +H2O +KCl

b) Complete dissociation occurred to 100 gm of CaCO3 and MgCO3
by heating. The decrease in weight is 50% of actual weight. Calculate
the weight of MgCO3 in the actual weight.


Question 7:                                             (20 marks)
a) Commercial sulfuric acid (98 %) is produced by combustion of
pure sulfur (impurity 80%) in air. Oxidization of SO2 to SO3
occurred in presence of catalyst. Finally the gas produce absorbed
indirect by water. How much the daily production of pure sulfur for
factory produces 200 Tone of acid per day?
b) Calculate pH of adding the following amount of NaOH (0.01M) to
100 cm3 of benzoic acid (0.01M): 0 , 50 cm3 , 100 cm3 , 150 cm3. Then
draw the relation between pH, Vb.
Knowing that dissociation constant is 6.4 x 10 –05.
c) What is the molar concentration of a solution containing 20 g of
C2H5OH in 500 cm3 of solution?

Question 8:                                           (15 marks)
a) Define the following terms:
1- Indicators        2- Titration   3- Ionic product of water
b) Sodium Chloride weighing 600g is mixed with 200 gm potassium
Chloride. Find the composition of the mixture in:
1- Weight %              2- mole %
c) A solution of Caustic Soda in water contains 20% NaOH (by wt) at
60oC. The density of the solution is 1.196 g/cm3. Find the
concentration of Caustic Soda in g/l. Also find the molarity,
normality and molality of the solution.

Question 9:                                                     (25 marks)
a) A Cetonitrite is produced by the reaction of propylene, ammonia
and oxygen.
       C3H6 + NH3 + 3/2 O2  C3H3N + 3H2O
The feed contains 10 mole % propylene, 12 % ammonia, and 78 %
air. A fractional conversion of 30% of the limiting reactant is
achieved. Determine which reactant is limiting, the percentage by
each of the other reactant is in excess, and the molar flow rates of all
product gas constituents for a 30 % conversion of the limiting
reactant, tacking 100 mole of feed as a basis.
B) Copper and nickel are completely soluble in the solid state. Do
solid, liquid, and vapour phases co-exist together at one single point
only? Why?
C) For the cell, Zn(s) / ZnCl2 (sol) / AgCl (s) , Ag (s) , the E.M.F at 25oC
was found to be 1.015 volts and its temperature coefficient equals
–4.02 x 10-4 V/K. Write the electrodes and cell reactions, then
calculate ΔG, ΔH and, ΔS.
D) A constant current was passed through a solution of CuSO4 for
1.00 hr. An ammeter connected in the circuit read 0.5 amperes. The
cathode gained 0.596 gm of copper. What is the error of the meter?
E) We want to plate 50 gm of copper Cu from CuSO4 bath. How
many coulombs are required?


   Knowing that the atomic masses of the following elements are:
   C=12   ,      H=1        ,     Cl=35.5      ,      S=32
      Cu= 63.5         ,     O = 16        ,    Na = 23        ,     Zn = 65
   Ca=40 ,          Mg=24
Cairo University                                 June 2005
Faculty of Engineer                            First Year Exam
Biomedical Engineering Dept.               Time allowed 3 hrs

                          CHEMISTRY
Question 1:                                              (12 marks)
Write detailed notes about: (Write equation whenever possible)
   5- Sp 3 hybridization
   6- Heterolysis
   7- Resonance
   8- Vulcanization of Wbleer
Question 2: Classify:                                    (12 marks)
    1- Organic Compounds                     2- Alkadienes
    3- Dihalogen Compounds                   4- Dihydric Alcohols
Question 3:                                              (10 marks)
Write Chemical Reactions to Show:
   4- Orientation in benzene ring.
   5- Preparation of ethers.
   6- Conversion of primary to secondary and tertiary alcohols.
Question 4:
    Starting from ethylene prepares the following: (10 marks)
             1- Oxalic acid                  2- Dioxane
             3- Phorone
    Starting from acetylene prepares the following: (10 marks)
             1-Crotonaldehyde                      2- Teflon
Question 5:                                              (10 marks)
Explain (with reactions) the industrial method for preparing:
    1- Ethylene glycol                       2- Benzene
    3-Ethyl alcohol
Question 6:                                              (15 marks)
a) Write complete and balanced equations for each of the following
reactions:
16.FeS2 + O2  Fe2O3 + SO2
17.H2SO4 + NaOH  Na x SO4 + H2O
                                    Δ
18.CaCO 3  --------- + COx
19.Zn + FeCl2  ZnCl2 + Fe
b) Commercial sodium “hydrosulfite” is 90.1 % pure Na2S2O4. How
much of the commercial product could be made by using 100 metric
tons of zinc with a sufficient supply of the other reactants? The
reactions are:
                                Zn + 2 SO2         ZnS2O4
              ZnS2O4 + Na2CO3  ZnCO3 + Na2SO4
Question 6:                                              (15 marks)
a) How much carbon monoxide is produced from the reaction of 1.00
kg of octane, C3H18 , and 1.00 kg of oxygen?
b) How much potassium chloride is produced from the reaction of
2.00g of K and 3.00 g of Cl2?
Knowing that K has an atomic mass of 39 and Cl of 35.5.
c) How much 83.4 % pure salt cake (Na2SO4) could be produced
from 250 kg of 94.5 % pure salt.
Question 7:                                              (15 marks)
a) Define the following terms and give also their units:
1- Molality 2- Molar Concentration            3- Normality of a solution
b) Calculate the following:
    9- Molar concentration of sulfuric acid solution of density 1.198
       g/cm3, containing 30 % H2SO4 by mass.
    10-       The molality of the acid mentioned in (1).
c) What is the molar concentration of a solution containing 20 g of
C2H5OH in 500 cm3 of solution?
Question 8:                                              (25 marks)
A) Define and write the equation relating each of the following items:
i) A phase ii) The number of components iii) The number of degrees
of freedom.
iv) Consider n liquids of which only K are soluble ( K< n ) No
chemical reactions take place. Prove that under boiling conditions
the number of degrees of freedom is K.
v) A mixture of liquid, ice, and water vapor.
B) What length of time is required to apply a metal surface of nickel
coating with an average thickness of 0.003 cm at an average density
of 40 ma / cm2, if the current efficiency is 95 %? Density of nickel is
8.9 gm / cm 3.
C) The conductance of a 0.1 m KCl was found to be 0.04006 -1 and
its specific conductivity is known to be 0.012886 -1 cm -1. Using the
same cell the measured resistance of 0.01 m acetic acid was found to
be 5.035 x 10 2 . Calculate the degree of dissociation of 0.01 m acetic
acid solution knowing that the equivalent conductivity at infinite
dilution of sodium acetate (Na Ac), hydrochloride acid (HCl) and,
sodium chloride (NaCl) are: 91 -1, 426.1 -1and,126.5 -1
respectively.
D) Knowing that a current of 5 amp flowing for exactly 30 minutes in
a ZnSO4 solution deposits 3.048 g of Zn at the cathode, Calculate the
equivalent weight of Zn.
E) Calculate Vant Hoff’s coefficient for 30 % ionization of silver
chloride solution using 5 Faradays.


   Knowing that the atomic masses of the following elements are:
   C=12    ,     H=1        ,     Cl=35.5      ,      S=32
   Zn = 65 ,     Na = 23    ,     O = 16


Cairo University                                           June 2005
Faculty of Engineer                                       First Year Exam
Biomedical Engineering Dept.                         Time allowed 2 hrs

                                CHEMISTRY
Question 1:
   i)     Write short notes about:
           Decomposition reaction
           Displacement reaction
           Redox reaction
   ii)    What is the pH of a solution prepared by mixing 10 ml of 0.1 M acetic
          acid,HC2H3O2, and 20 ml of 0.2 M sodium acetate, NaC2H3O2,
           a) Initially and
           b) After the further addition of 2 drops? (0.1ml) of 12 M hydrochloric
           acid,HCl? The value of the acid dissociation constant, Ka, for acetic
           acid, is 1.8 x 10-5.
   iii)   Calculate [OH-] in a 1 M solution of NaOCN. Ka for HOCN is 2.2 x10-4
   iv)    A current of 15 amperes is employed to plate nickel in a NiSO4 bath.
          Both Ni and H2 are formed at the cathode. The current efficiency with
          respect to formation of Ni is 60 %.
          a) How many grams of nickel are plated on the cathode per hour?
          b) What is the thickness of the plating if the cathode consists of a sheet
              of metal 4 centimeters square which is coated on both faces? The
              density of nickel is 8.9 g/cc.
          c) What volume of H2 (S.T.P) is formed per hour?
Question 2:
   i)     Balance the following oxidation – reduction equation:
           K+MnO4- + K+Cl- + (H+)2SO4--  Mn++SO4-- + H2O +Cl2
           Zn + Na+NO3- +Na+OH-  (Na+)2ZnO2-- + NH3 +H2O
           FeS2 + O2  Fe2O3 + SO2
   ii)    A volume of 12.53 ml of 0.05093 M selenium dioxide, SeO2, reacted
          with exactly 25.52 ml of 0.1M CrSO4. In the reaction, Cr2+ was
          oxidized to Cr3+.To what oxidation state was the selenium converted
          by the reaction?
   iii)   A mixture of NaHCO3 and Na2CO3 weighed 1.0235 g. The dissolved
          mixture was reacted with excess Ba(OH)2 to form 2.1028 g BaCO3, by
          the reactions:
          Na2CO3 +Ba(OH)2  BaCO3 +2NaOH
          NaHCO3 + Ba(OH)2  BaCO3 + NaOH + H2O
          What was the percentage NaHCO3 in the original mixture?
  iv)     A mixture of 1 ton of CS2 and 2 tons of Cl2 is passed through a hot
          reaction tube, where the reaction:
           CS2 + 3 Cl2  CCl4 + S2Cl2 take place.
          a) How much CCl4 can be made by complete reaction of the limiting
             starting material?
          b) Which starting material is in excess, and how much of it remains
             unreacted?
Question 3:
   i)     What is meant by dissociation of weak acid?
   ii)    Calculate the pH of a 0.1 M NH3 solution. (Ka = 1.8 x 10-5 )
   iii)   Calculate the molarity, molality, and mole fraction of ethyl alcohol
          (C2H5OH) in a solution of total volume 95 ml prepared by adding 50
          ml ethyl alcohol (density = 0.789 g/ml) to 50 ml water (density= 1
          g/ml). Calculate the molatity of water in alcohol.
   iv)    Define Indicator then what indicator should be used for the titration
          of 0.1 M KH2BO3 with 0.1 M HCl? (Ka=7.3x 10-10 )
                       Indicator                          pH
                    Methyl Orange                       2.8-3.8
                        Litmus                           5-8.1
                      Methyl red                        3.6-6.1
                      Phenol red                        6.8-8.6
   v)     Calculate the pH of 50 ml of 0.1 M acetic acid solution to which each
          of the following quantities of o.1 M NaOH has been added: a) 15 ml
          b) 25 ml c) 40 ml d) 49 ml e) 50 ml f) 51 ml g) 60 ml h) 70 ml.
          Draw a smooth cuvre through the points which result. (Ka = 1.8 x 10-5
Question 4:
   i)     Consider n liquids of which only K are soluble ( K< n ) No chemical
          reactions take place. Prove that under boiling conditions the number
          of degrees of freedom is K.
   ii)    Calculate the pH of 1x 10 -3 M sodium phenolate. NaOC6H5. Ka for
          HOC6H5 is 1.05 x 10-10.
   iii)   The conductance of a 0.1 m KCl was found to be 0.04006 -1 and its
          specific conductivity is known to be 0.012886 -1 cm -1. Using the
          same cell the measured resistance of 0.01 m acetic acid was found to
          be 5.035 x 10 2 . Calculate the degree of dissociation of 0.01 m acetic
          acid solution knowing that the equivalent conductivity at infinite
          dilution of sodium acetate (Na Ac), hydrochloride acid (HCl) and,
          sodium chloride (NaCl) are: 91 -1, 426.1 -1and,126.5 -1
          respectively.
   iv)    Strawberries contain 15 % solids and water 85 % by mass. To
          make strawberry jam, crushed strawberries and sugar are
          mixed in a 45: 55 ratio, and the mixture is heated to evaporate
          water until the residue contains 1/ 3 water by mass. Draw and
          label a flowchart of this process, and use it to calculate how
          many Kgs of strawberries are needed to make 1 Kg of jam.
Question 5:
   i)     A Cetonitrite is produced by the reaction of propylene, ammonia and
          oxygen.
          C3H6 + NH3 + 3/2 O2  C3H3N + 3H2O
          The feed contains 10 mole % propylene, 12 % ammonia, and 78 %
          air. A fractional conversion of 30% of the limiting reactant is
          achieved. Determine which reactant is limiting, the percentage by
          each of the other reactant is in excess, and the molar flow rates of all
          product gas constituents for a 30 % conversion of the limiting
          reactant, tacking 100 mole of feed as a basis.
   ii)    During the electrolysis of a solution of CuSO4 in which 5.0473 gm of
          CuSO4 was dissolved in 94.953 gm of water, 1.548 gm of Ag were
          deposited in a coulometer placed in series with the CuSO4 solution.
          After electrolysis 137.7422 gm of anode solution was found to contain
          7.7022 gm of CuSO4. Calculate tSO4--.
   iii)   For the cell, Zn(s) / ZnCl2 (sol) / AgCl (s) , Ag (s) , the E.M.F at 25oC was
          found to be 1.015 volts and its temperature coefficient equals –4.02 x
          10-4 V/K. Write the electrodes and cell reactions, then calculate ΔG,
          ΔH and, ΔS.


   Knowing that the atomic masses of the following elements are:
   C=12    ,     H=1        ,     Cl=35.5      ,      S=32
   Zn = 65 ,     Na = 23    ,     O = 16       ,     Ba = 137.33


Cairo University                                            June 2006
Faculty of Engineer                                         First Year Exam
Biomedical Engineering Dept.                          Time allowed 2 hrs

                                CHEMISTRY
Question 1:
a) Write complete and balanced equations for each of the following
reactions:
           20.HClO4 + P4O10  H3PO4 + Cl2O7
           21.Fe2(SO4 )3 + BaCl2  FeCl3 + BaSO4
                                 Δ
           22.CaCO 3  --------- + COx
           23.HCl + KNO2+ CoCl2  K3Co(NO2)6 + NO +H2O +KCl
b) Complete dissociation occurred to 100 gm of CaCO3 and MgCO3
by heating. The decrease in weight is 50% of actual weight. Calculate
the weight of MgCO3 in the actual weight.

Question 2:
a) Define the following terms and give also their units:
1- Molality 2- Molar Concentration         3- Normality of a solution
b) Calculate the following:
   1- Molar concentration of sulfuric acid solution of density 1.198
      g/cm3, containing 30 % H2SO4 by mass.
   2- The molality of the acid mentioned in (1).
c) What is the molar concentration of a solution containing 20 g of
C2H5OH in 500 cm3 of solution?

Question 3:
a) The conductance of a 0.1 m KCl was found to be 0.04006 -1 and
its specific conductivity is known to be 0.012886 -1 cm -1. Using the
same cell the measured resistance of 0.01 m acetic acid was found to
be 5.035 x 10 2 . Calculate the degree of dissociation of 0.01 m acetic
acid solution knowing that the equivalent conductivity at infinite
dilution of sodium acetate (Na Ac), hydrochloride acid (HCl) and,
sodium chloride (NaCl) are: 91 -1, 426.1 -1and,126.5 -1
respectively.
b) Knowing that a current of 5 amp flowing for exactly 30 minutes in
a ZnSO4 solution deposits 3.048 g of Zn at the cathode, Calculate the
equivalent weight of Zn.
c) Calculate Vant Hoff’s coefficient for 30 % ionization of silver
chloride solution using 5 Faradays.

Question 4:
a) A Cetonitrite is produced by the reaction of propylene, ammonia
and oxygen.
       C3H6 + NH3 + 3/2 O2  C3H3N + 3H2O
The feed contains 10 mole % propylene, 12 % ammonia, and 78 %
air. A fractional conversion of 30% of the limiting reactant is
achieved. Determine which reactant is limiting, the percentage by
each of the other reactant is in excess, and the molar flow rates of all
product gas constituents for a 30 % conversion of the limiting
reactant, tacking 100 mole of feed as a basis.
b) Copper and nickel are completely soluble in the solid state. Do
solid, liquid, and vapour phases co-exist together at one single point
only? Why?



   Knowing that the atomic masses of the following elements are:
   C=12    ,     H=1        ,     Cl=35.5      ,      S=32
   Zn = 65 ,     Na = 23    ,     O = 16       ,      N=14
   Ca=40 ,       Mg=24

				
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