Chemistry Model Exam
Answer four questions only. All equation must be written balanced
First Question: ( 15 Marks )
Firstly: Choose the correct answer:
1- The transition element that has electronic configuration [ 18Ar] 4s2,3d10 is
…………………
A) Scandium
B) Vanadium C) Manganese D) Copper
2- On adding lead acetate solution to the solution of ………….., a black
precipitate is formed.
A) Sodium sulphate B) sodium nitrate
C) sodium phosphate D)
sodium sulphide
3- In the reaction: 4NO (g)
2N2 (g) + 2O2 (g) , ∆H= +180kj/mol
………………. leads to decrease the formation of oxygen gas
A) Adding nitric oxide gas
B) adding excess Helium gas in medium of reaction
C) Heating the medium of the reaction D) cooling the medium of the reaction
4- If the standard reduction potential of zinc and nickel are (-0.76) volt and
(-0.23) volt respectively, the e.m.f of the cell formed from both electrodes
equal ………… volt.
A) -0.53
B) 0.175
C) 0.53
D) 0.99
5- Ethyne gas is prepared by adding water to ………………
A) Soda lime
B) calcium oxide
C) calcium carbide
D) calcium
carbonate
6- 1, 2, 3 trihydroxy benzene is called ……………..
A) Ethanol B) Picric acid
C) Pyrogallol D) Catechol
Secondly:
1- Mention one use for the following:
a) Adding coke in Blast furnace charge on extracting iron.
b) Catalyst in industrial process.
c) Salt bridge in the galvanic cell.
d) Ethylene glycol.
2- Explain that phenol has more acidic property than ethanol.
3- What is the effect of mixture of hot concentrated sulphuric and nitric
acid on benzene?
4- How can you differentiate between:
a) Iron (II) chloride and Iron (III) chloride.
b) Ethanol and acetic acid.
Second Question: ( 15 Marks )
Firstly: write the scientific expression for each of the following.
1- They are the elements in which 3d-sublevel is successively filled with
electrons and they occupy the fourth period in the periodic table from
group 3 to group 12.
2- It is a chemical substance that change their colours in the reaction medium
to detect the end point of the reaction.
3- It is the equilibrium arising between molecules of a weak electrolyte and
the ions resulting from it.
4- The quantity of material formed or consumed at any electrode is directly
proportional to the quantity of electricity that passes in the electrolyte.
5- They are organic compounds consist of carbon and hydrogen only.
6- It is the combination process of large number of compound molecules to
form a huge molecule which has a big molecular mass.
Secondly:
1- Write the chemical formula according to IUPAC system for the
following compounds:
2- 2- By chemical equation how can you obtain?
a- Iron (III) oxide from iron (II) oxalate.
b- Black carbon from sodium acetate.
3- Compare between:
A) Paramagnetic substance and Diamagnetic substance.
B) Complete reactions and reversible reactions.
Third Question: ( 15 Marks )
Firstly:
1- Write down the scientific explanation for each statement:
1. Boiling point of carboxylic acids is higher than that of corresponding
alcohols.
2. Concentrated sulphuric acid is added in ester formation.
3. Manganese (II) ion is difficult to be oxidize to Manganese (III).
4. Diluted hydrochloric acid is used to differentiate between sodium
carbonate and sodium nitrite salts.
5. Lead acid battery is considered as reversible cell.
2- Write the equilibrium constant ( KC ) for the following reaction:
Ag2O (s) + 2HNO3(aq)
2AgNO3 (aq) + H2O (l)
Secondly:
1- By using the following table determine:
1
CH3COOCH3
2
CH3 CH2 OH
3
CH3 CH2 COOH
4
C6H6
5
CH3OH
6
CH3COO CH2 CH3
1- The compound which does not react with caustic soda.
2- The product of hydrolyzing of compound (6).
3- The compound that gives effervesce on reacting with sodium
bicarbonate.
2- Calculate the mass of copper metal deposited on the cathode on passing a
current of 10 amperes for half an hour in the copper (II) sulphate solution.
( Cu=63.5)
3- Identify the basic radical of the following two salt solutions, on adding
sodium hydroxide to each of them the first gives white gelatinous
precipitate and the second gives greenish-white precipitate. (write the
chemical equations)
4- By chemical equations prove that magnetic iron oxide is a mixed oxide.
Fourth Question: ( 15 Marks )
Firstly:
1- Aluminum metal is electrically extracted from bauxite. Illustrate with
complete labeled diagram ,and with the help of by balanced chemical
equations :
a- The reaction takes place at the anode.
b- The reaction takes place at the cathode.
2- How can you differentiate practically between: sodium chloride and sodium
bromide?
3- Illustrate how can you prepare acetic acid in industry?
Secondly:
1- Show by chemical equation show to prepare:
a) Ethyl acetate ester from ethanol
b) Toluene from benzene.
2- Write the structural formula of the following:
a) 2,2-dimethyl butanoic acid
b) ethylene glycol
3- Arrange the following ions in an ascending order according to their
magnetic moment: Cu+ , Fe2+ , Co2+ , Mn2+
4- Calculate the solubility degree of silver sulphate Ag2SO4 in water, provided
that its solubility product Ksp equals 1.4x10-5
Fifth Question: ( 15 Marks )
Firstly:
1- Calculate the concentration of [OH-] ions in a solution, provided that the
concentration of [H+] ions is 3x10-7mole/liter.
2- Illustrate with chemical equations that: 1-propanol is a primary alcohol,
while 2-propanol is a secondary alcohol.
3- What is the role of the following scientists and their contribution in
progress of chemistry: a) wohler b) kekule c) Markownikoff
Secondly:
1- Write the symbolic equations and conditions of reaction which illustrate
the following reactions:
a) Catalytic hydration of ethene.
b) Heating ethanol with sulphuric acid at 140°C
2- Mention one use for:
a) Potassium permanganate
b) Natural gas in Midrex furnace c) Teflon
3- What is meant by:
a- Catalytic activity of transition elements
b- Law of mass action
c- Anodic protection
d- The faraday