Which of the following substances is an example of a fine chemical?
Απάντηση
(C)
Ethylene
2
The IUPAC name of the compound represented by the structure below is ?
Απάντηση
(A)
2- chloro but-I ,3-diene.
3
Which or the following substances is a polypeptide?
Απάντηση
(C)
Protein
4
Which or the following products could be formed during incomplete combustion of a hydrocarbon.
i.Carbon ii. Hydrogen III. Carbon (Il) oxide
Απάντηση
(C)
I and III only
5
What quantity of electrons is lost when one mole of iron (II) ions is oxidized to iron (III) ?
Απάντηση
(B)
3 moles
6
What is the mass of silver deposited when 24,125 C of electricity is passed through a solution or silver salt.
[Ag = 108, IF = 96,500 C ]
Απάντηση
(D)
27g
7
Equal masses of calcium trioxocarbonate(iv) were added to dilute hydrochloric acid at the temperature specified. Under which of the following conditions would the reaction be slowest?
Απάντηση
(A)
Calcium trioxocarbonate ( iv ) chips a 20°C
8
The high solubility of ethanol in water is due to?
Απάντηση
(D)
hydrogen bonding
9
Which of the following pairs of properties of alkali metals decreases down the group?
Απάντηση
(D)
First ionization energy and melting point
10
The most suitable process of obtaining water from an aqueous solution of sugar i
Απάντηση
(B)
Distillation
11
Group VIl elements in their combined states are called?
Απάντηση
(C)
Halide
12
When an ionic bond is broken, bonding electrons are
Απάντηση
(B)
gained by the most electropositive atom
13
The oxidation state of chlorine in NaClO\(_3\) is?
Απάντηση
(C)
+5
14
A balanced chemical equation is based on the law of?
Απάντηση
(D)
Conservation of mass
15
Which of the following pairs of elements has the greatest difference in electronegativity?
Απάντηση
(A)
Na and F
16
A factor that is considered most important when siting a chemical industry is?
Απάντηση
(B)
nearness to raw materials
17
The boiling point of pentane is higher than that of propane because?
Απάντηση
(B)
Pentane has more covalent bonds to break
18
Which of the following solids would not decompose on heating?
Απάντηση
(C)
Potassium trioxocarbonate (IV)
19
The following molecules have double covalent bonds between two atoms except?
Απάντηση
(D)
water
20
The type of isomerism exhibited by cis and trans isomers is?
Απάντηση
(B)
geometrical
21
Which of the following compounds has the lowest boiling point?
Απάντηση
(A)
C\(_4\)H\(_10\)
22
An alkanol containing 60% carbon by mass would have a molecular formula [H=1.0. C-12.0, O= 16.0]
Απάντηση
(C)
C\(_3\)H\(_7\)OH
23
Which of the following compounds would release hydrogen when reacted with sodium metal?
I. CH\(_3\)COOH
II. CH\(_3\)CH\(_2\)OH
III. CH\(_3\)COOCH\(_3\)
Απάντηση
(B)
I and II only
24
Which of the following substances is not a reducing agent?
Απάντηση
(C)
O\(_2\)
25
Which of the following statements is correet for a reaction at equilibrium?
Απάντηση
(C)
The rates of the forward and backward reactions are equal
26
Which of the following reactions are always exothermic? 1. Neutralization Il. Decomposition III. Combustion
Απάντηση
(B)
I and III only
27
Which of the following standard conditions is not correct about energy changes?
Απάντηση
(D)
ΔH at 298 K is the activation energy
28
f 5.0 cm\(^-3\) of 0.200 mol dm(^-3\) Na\(_2\)CO\(_3\) was diluted to 250cm(^-3\) solution, what would be the concentration of the resulting solution?
Απάντηση
(A)
0.004 mol dm(^-3\)
29
The initial volume and pressure of a given mass of gas is V and 3.P. What is its pressure if its volume is increased to 2V at constant temperature?
Απάντηση
(C)
\(frac{3}{2}\) P
30
What volume of oxygen at s.t.p is required to burn completely 7.5 dm\(^3\) of methane according to the following equation?
When 250 cm3 of a saturated solution of CuSO\(_4\) at 30°C was evaporated to dryness, 5.0 g of the salt was obtained..
What is the solubility of the salt at 30°C? [CuSO\(_4\) = 160]
Απάντηση
(B)
0.125
32
The bond between NH\(_3\) and H\(^+\) in NH4\(^+\) is?
Απάντηση
(A)
dative
33
Which of the following oxides has a giant covalent structure?
Απάντηση
(D)
SiO\(_2\)
34
Which of the following hydroxides is not readily soluble in water?
Απάντηση
(B)
Ca(OH)\(_2\)
35
Which of the following statements about the solubility of a salt is correct?
Απάντηση
(C)
Crystallization would be efficient in separating out a salt whose solubility increases considerably with temperature
36
How many moles of H\(_2\)SO4 are there in 50 cm\(^3\) of 0.108 mol dm\(^3\) solution of the acid?
Απάντηση
(B)
5.4 x 10\(^{-3}\)
37
If 20 cm\(^3\) of sodium hydroxide was neutralized by 20 cm\(^3\) of 0.01 mol dm\(^3\) tetraoxosulphate(VI) acid, what is the concentration of the sodium hydroxide solution?
Απάντηση
(B)
0.020
38
"Electrons always occupy the lowest empty energy level" is a statement of
Απάντηση
(A)
Aufbau Principle
39
Which of the following metals does not react with water to produce hydrogen?
Απάντηση
(A)
Copper
40
Which of the following arrangement of elements is in decreasing order of electronegativity?
Απάντηση
(D)
P, Si, Al, Mg, Na
41
The metallic bond in magnesium is stronger than that in calcium because magnesium has a
Απάντηση
(B)
smaller atomic size
42
Consider the reaction represented by the following equation:
AgNO\(_3\) + NaCl → AgCl + NaNO\(_3\).
The steps that could be taken to obtain pure dry sample of AgCI (s) from the mixture includes
Απάντηση
(C)
filtering, washing and drying
43
How many electrons does \({31}_{15}\)P\(^3-\) contain?
Απάντηση
(D)
18
44
The atomic number of an atom would be equal to its mass number if it
Απάντηση
(C)
does not contain neutrons
45
Which of the following processes is not exhibited by atoms in order to attain more stable electron configuration?
