المراجعة النهائية فى مادة الكيمياء لغات - الجزء الثانى

المراجعة النهائية فى مادة الكيمياء لغات - الجزء الثانى



Question(5) ( 10 marks)

(A) Mention the scientific reason:

3- Sulphuric acid is stronger than orthophoshoric acid and weaker than perchloric acid

4- There are no positive hydrogen ions(protons) in the aqueous solution of strong acids.

5- The catalyst does not affect the position of equilibrium in the reversible reactions

6- Nickel cadmium battery is basic whereas lead battery is acidic.

7- The ions of s,p block elements are colourless.

(B) Compare between each of the following :
1- Organic and inorganic compounds with regards to the solubility

2- Complete and reversible reactions

3- Building up principle and Hund's rule

(C) The structural formula of:
1- Naphthaline

2- Diphenyl

Did you consider these two compounds isomers? Why?

Question(6) ( 10 marks)
(A) What is meant by :

1- Le chatelier's principle

2- Substatutional alloys

3- Hybridization

(B) Illustrate by symbolic equation with respect to energy ( exothermic – endothermic ) each of the following:

1- Electron affinity

2- Second ionization potential

(C) Ethyne gas reacts with hydrogen bromide gas in two steps

1- Why the reaction takes place in two steps?

2- Write the two balanced chemical equation for this reaction

3- Mention the IUPAC nomenclature of for the final product

4- What happens on adding 5 moles of hydrogen bromide to 1 mole of ethyne (s.t.p)?

(D) What are the quantity of electricity in ( coulombs) necessary to separate 11.2 gram of iron from a solution of iron III chloride ?

Where the cathode reaction is:
Fe3+ + 3e- Fe0

Model answer-1
Question(1) ( 10 marks)

(A) ( 6 marks ) ( 6 x 1 = 6 )
1- c) the energy level in the atom
2- b) Nitrous oxide
3- d) CH3-O-CH3
4- c) Calcium fluoride and calcium ohosphate
5- a) Dolomite
6- d) 2 x 6.02 x 1023 ions
(B) ( 3 marks ) ( 3 x 1 = 3 )
1- Salicylic acid: manufacture of cosmetic- maks the skin sof and flexible –
protect from sun rays- treatment of cold diseases
2- Ethylene glycol :antifreeze substance – in radiators –hydrulic break –
ptinting ink- polyethylene glycol(Dacron-cassette tapes-films)
3- Teflon: in making cooking utensils – surgical threads

( C ) one mark 1/2 for each orbital
π and δ are molecular orbitals
S and SP2 are atomic orbitals

Question(2) ( 10 marks)

( A ) 5 marks ( 5 x 1 = 5

1- Orbital

2- Oxidation number

3- Roasting

4- Avogadr's law

5- The (rate) speed of chemical reaction

(B) ( 4 marks )

1- CH3COONa + NaOH CaO + ∆ CH4 + Na2CO3 ( 1 mark)
the apparatus ( 1 mark )

2- Two marks ( 1/2 for each equation and 1/2 for the condition = 2 )
CH4 + Cl2 I.S.L. CH3Cl + HCl
CH3Cl + Cl2 I.S.L. CH2Cl2 + HCl
CH2Cl2 + Cl2 I.S.L. CHCl3 + HCl

(C) one mark KC =

Question(3) ( 10 marks)
( A ) ( 4 marks) one mark for each detecton
dtection Fe3+ Cu2+
Additing NaOH solution to both of them Reddish brown ppt. of Fe(OH)3 is formed blue ppt. of Cu(OH)2 is formed
Equation FeCl3+3NaOH
3NaCl + Fe(OH)3
Reddish brown ppt CuCl2+2NaOH
2NaCl + Cu(OH)2
Blue ppt

2- Two marks
One mole of NaOH = 23+16+1 = 40 gm.
No. of moles = = 0.15 mole
Concentration = = 1 mole/liter

1- C6H5OH + NaOH C6H5ONa + H2O 1 mark
2- CH3COOC2H5 + NaOH ∆ CH3COONa + C2H5OH 1 mark
3- NH3+CO2+NaCl+H2O NaHCO3 + NH4Cl 1 mark
2NaHCO3 ∆ Na2CO3 + H2O + CO2 1 mark


(D) Two marks
Na2CO3 2Na+ + CO32-
2H2O 2H+ + 2OH-
---------------------------------------------------------------------------------------
Na2CO3 + 2H2O 2Na+ + 2OH- + H2CO3
According to Le Chatelier 's principle concentration of OH- increases
So it has basic effect

-------------------------------------------------------------------------------------------------
Question(4) ( 10 marks)
(A) 3 marks 3 x 1 = 3
1- Kekule
2- Heisenberg
3- Ostwald

(B) 4 marks

1- two marks
alkane CnH2n+2
No. of hydeogen = 3x2 +2 = 8 atoms
The fornula is C3H8
% of carbon = = =
x 100 = x 100 = 81.82%

2 - Two marks
a) Asprine
b) Pecric acid

(C) Two marks
At anode: 3O2- O2 + 6e-
At cathode : 2Al3+ + 6e- 2Al
Total reaction: 3O2- + 2Al3+ O2 + 2Al
Reaction at carbon electrode 2C + O2 ∆ CO2 + CO

(D) one mark
2K + O2 K2O
No. of oxygen mole = half mole

------------------------------------------------------------------------------------------------
Question(5) ( 10 marks)
(A) 5 marks
1- Sulphuric acid = SO2(OH)2
Orthophoshoric acid = PO(OH)3
Perchloric acid = ClO3(OH)

Because the no. of oxygen not linked to hydrogen in perchloric acid more
than that in Sulphuric acid which is Orthophoshoric acid
as the no. of oxygen not linked to hydrogen increases the acidity increases

2- Because hydrogen ion combines with water by coordinate bond forming
hydronium ion
H2O + H+ H3O+

3- Because it affect the speed of the reaction only but it not affect the equilibrium position

4- Because the electrolyte in nickel –cadmium battery is KOH ( base) while in lead battery the electrolyte is H2SO4 ( acid)

5- The elements or ions of s block the d sublevel is empty (d0) – while in p-block elements the d sublevel is completely filled (d10) then element or ion will be coloured if sublevel d has unpaired electrons

(B) 3 marks 3 x 1 = 3
One comparison is enough for each one
Organic compounds Inorganic compounds
1- not soluble in water
2- soluble in organic solvent 1- most of them soluble in water
2- not soluble in organic solvent

Complete reaction Reversible reaction
1- procced in one direction
2- products can not give reactant
3- one of the product escapes
4- Mg+2HCl MgCl2+H2 1- procced in forward and backward
2- products can give reactants
3- Products and reactants are foind
N2 + 3H2 2NH3


Building up Hund's rule
Electrons occupy energy levels in the order of increase energy sublevel (the lowest energy sublevel is filled first) No pairing of electrons takes place in a given sublevel util each orbital contains one electron


(C) Two marks
1- Naphthaline (C10H8)

2- Diphenyl (C12H10) ___


They are not isomers , because they have different molecular formula

Question(6) ( 10 marks)

(A) 3 marks 3 x 1 = 3
1- The change in any condition of a chemical equilibrium such as concentration, pressure or temperature causes shift of the equilibrium in the direction which will oppose this chamge

2- Some atoms of an element are replaced by atoms of another element which have the same diameter, the same crystal form or the same chemical properties

3- Two or more orbitals close in energy are mexed together to form hybrid orbitals equal in energy

(B) Two marks
Electron affinity : exothermic
X + e- X- + energy

Second ionization energy : endothermic
M+ + energy M2+

(C) 3 marks
1) Because triple bond has two pi bond so it is broken in two steps

2) H-C=C-H + HBr H2C=CHBr
H2C=CHBr + HBr H3C-CHBr2

3) the name according to IUPAC is 1,1 dibromoethane

4) Ethyne has triple bond 2pi biond can broken and two molecules of hydrogen bromide are added while the rest three molecule do not react

(D) 2 marks
Equivalent weigt of iron III (Fe3+)
= = 18.62 gm
Mass =
Quantity of electricity =
= 58045.1 coulomb

The student will answer only five questions
Total marks = 5 x 10 = 50 marks
Maximum marks = 50 marks
Minimum marks = 20 marks

الدرجة النهائية من 50 ( يجيب الطالب عن 5 اسئلة فقط )
درجة النجاح = 20 درجة ( 40% من الدرجة الكلية )