Sunday 7 February 2016

CHEMISTRY EXAM


SOCIAL AWARENESS ORGANIZATION (SAO)
EXTRA STUDIES DEPARTMENT
URBAN WEST ZONE EXAMINATION SYNDICATE
FORM FOUR MOCK EXAMINATION

032/1                                       CHEMISTRY 1
(For both School and Private Candidates)

Time: 3 Hours                                                       Thursday, 10th July 2014a.m.

Instructions

1.                  This paper consists of section A, B, and C.

2.                  Answer all questions from each section. 

3.                  Calculators and cellular phones are not allowed in the examination room.

4.                  Write your examination Number on every page of your answer booklet(s).

5.                  The following constants may be used where necessary.

Atomic masses
H = 1, C = 12, N = 14, O = 16, Na = 23, S = 32, Cl = 35.5, Mg = 24,         

G.M.V at S.T.P = 22.4dm3/mole = 22400cm3/mole.
1Faraday = 96500C
Avogadro’s constant = 6.2×1023 particle/mole.













SECTION A (20Marks)

Answer all questions in this section

1.      For each of the items (i) – (x), choose the correct answer from the given alternatives and write its letter beside the item number.
          
(i)          Chemistry is a study of
A.    The composition, structure and properties of matter
B.     All scientific process
C.     Experiment carried out in industries
D.    Chemicals used in laboratory
E.     Physical process

(ii)       A Bunsen burner produces the hottest flame when
A.    The air holes are closed                                      D.  The air holes are half opened
B.     The air holes are fully opened                           E.  Completely closed
C.     The gas tap is opened at 450 clockwise

(iii)     ______ is the second step in the scientific procedures
A.    Data analysis                                                        D.  Observation
B.     Hypothesis                                                            E.  Data interpretation
C.     Conclusion

(iv)     The process by which a substance changes directly from solid to gaseous state without passing the liquid state is called
A.    Melting                                                                  D.  Freezing
B.     Boiling                                                                   E.  Sublimation
C.     Evaporation

(v)        Syrups are example of
A.    Solution                                                                 D.  Mixture
B.     Filtrates                                                                 E.   Residue
C.     Suspensions

(vi)     A rapid chemical reaction that release energy in the form of light and heat is called
A.    Combustion                                                          D.  Heating
B.     Ignition                                                                  E.  Fire
C.     A reactant

(vii)   _____ is the common method used for producing hydrogen industrially
A.    Electrodes                                                             D.  Steam reforming
B.     Reduction                                                             E.  Oxidation
C.     Decomposition

(viii)      Fresh water constitutes about _____% of total water on the earth
A.    30                                                                           D.  0.3
B.     13                                                                           E.  3
C.     97

(ix)           What is nucleus?
A.    Neutrons                                                               D.  Electrons
B.     Protons                                                                  E.  Proton and neutron
C.     Proton and electron

(x)        ______  is an example of triprotonic acid
A.    H2SO4                                                                      D.  CH3COOH
B.     HCL                                                                         E.  HNO3
C.     H3PO4


2.      Match the items in List A with the responses in List B by writing the letter of the responses beside the item number
  
List A
List B
(i)             Gram molar volume of gas
(ii)          Standardization
(iii)        Electroplating
(iv)        Chemical equilibrium
(v)           Water gas
(vi)        Gangue
(vii)      Basic metal oxides
(viii)   Insoluble amorphous sulphur
(ix)        Still
(x)           Soil formation

A.             Weathering process
B.             Weather agent
C.             Fractional distillation
D.             Simple distillation
E.              Flower of sulphur
F.              Rhombic sulphur
G.             Group I metal oxide
H.             Group II metal oxide
I.                Unvalued ores
J.               Valued ores
K.             Co(g)  +  H2(g)
L.              Co(g)  +  N2(g)
M.           Stability of reactants and products
N.             Rate of reaction
O.             Coating of one metal by another during electrolysis process
P.              Purification
Q.             Titration
R.             Pipetting
S.              22400cm3/mole
T.              1 liter/mole  

SECTION B (54 Marks)
Answer all questions in this section
3.      (a)    Define the following terms
(i)          Fire
(ii)       Fire fighting

(b)    Name four (4) main parts made up hydrological cycle

4.      (a)    What do you understand by the term dilution?

(b)    What volume of commercial acid of 38% and density 1.18g/cm3 of Hydrochloric acid should be diluted to make 0.1M solution of 2litres?

5.      (a)    Name the following compound
(i)          Cu3P2
(ii)       N2O5

(b)    Element Z has atomic number of 10, whose isotopes A, B and C have atomic masses of 20, 21 and 22 in proportion of 90.8%, 0.3 and 9.2% respectively. Calculate the relative molecular mass of Z and write its electronic configuration and name

6.      (a)    In considering periodic table, explain briefly how Electro negativity, Ionization energy and Atomic radius of element vary, across the groups and down the groups.

(b)    Write the net ionic equation for the reaction of aqueous Potassium thiosulphate and Nitric acid.

7.      (a)    With the aid of chemical reaction, briefly explain why Ammonia dried by quick lime (Ca(OH)2) whiles the common drying agent such as concentrated sulphuric acid and calcium chloride are not used.

(b)    The reaction below shows a reaction between fluorine gas and sodium chloride. What is type of reaction? Why is it possible to take place?
        F2(g)  +  2NaCl(aq)                           2NaF(aq)  +  Cl2(g)

8.      (a)    Give the difference between physical strength and chemical strength of metal

      (b)    In conversion process of copper extraction. Copper (I) oxide is reduced by copper (I) sulphide to copper as self reduction. Why is it possible?

9.      (a)    Define the term pollution

(b)    Name four (4) gases that contribute to global warming and one source of each.
10.       (a)    Explain in brief why brown ring formed on Nitrate test disappears when disturbed while it is reversible?

         (b)    Why dry quenching is more favored than wet quenching of coke?

11.       (a)    Why most organic compounds have the same product in the combustion reactions?

         (b)    List down any four (4) causes of soil erosion.


SECTION C (26 Marks)

Answer all questions in this section

12.       “Electrolysis of Dilute Sulphuric acid is called the electrolysis of water”. By using well labeled diagram of Hoff – man apparatus and electrode reactions, give reasons for the validity of this statement.

13.       Mostly one organic compound is the derivative of the others. Verify this statement by using chemical reaction for the conversion of the following compounds.

               Alcanoic acid                 Alkane                Alkene                Alkyne


                                                                   Alkanol