Which of the following atoms contains the highest number of electrons in the outermost shell?
پاسخ دهید
(B)
10Ne
2
What is the electronic configuration of an element represented as 199X?
پاسخ دهید
(A)
1s 22s2 2p 5
3
Pauli Exclusion Principle is related to
پاسخ دهید
(A)
quantum numbers of electrons
4
Which of the orbitals 4s, 4p, 4d and 4f has the lowest energy?
پاسخ دهید
(D)
4s
5
Two radioactive elements Q and S have half-life periods of 10 hours and 20 hours respectively. Therefore
پاسخ دهید
(D)
S is more stable than Q
6
Calcium atom ionizes by
پاسخ دهید
(B)
losing two electrons
7
Which of the following properties increases down a group in the Periodic Table?
پاسخ دهید
(A)
Atomic radius
8
In the Periodic Table, the elements that loss electrons most readily belong to
پاسخ دهید
(A)
Group 1 A
9
Which of the following reactions is not feasible?
پاسخ دهید
(B)
Cl2 + 2NaF → 2NaCI + F2
10
Which of the following halogens is the most reactive?
پاسخ دهید
(A)
F2
11
The crystal layers in graphite are held together by
پاسخ دهید
(B)
van der Waals' forces
12
Which of the following compounds has the highest ionic character?
پاسخ دهید
(D)
KCI
13
If an element with high electron affinity combines with another element with low ionization energy the bond formed will be mainly
پاسخ دهید
(B)
ionic
14
One mole of a compound M(HCO3)2 has a mass of 162g. Calculate the relative atomic mass of M. [H = 1, C =12, O = 16]
پاسخ دهید
(D)
40
15
Exhaust fumes discharged from a smoky vehicle gradually become invisible as a result of
پاسخ دهید
(A)
diffusion
16
Which of the following movements can be described as random motion?
پاسخ دهید
(C)
Gas molecules colliding in a flask
17
Equal volumes of CO2 cnd CO at s.t.p have the same
پاسخ دهید
(D)
number of molecules
18
Gas molecules are said to be perfectly elastic because
پاسخ دهید
(A)
they collide without loss of energy
19
What volume of hydrogen is produced at s.t.p. When 2.60 g of zinc reacts with excess HCI according to the following equation? Zn(s) + 2HCI(aq) → ZnCI 2(aq) + H2(g) [Zn = 65; 1 mole of a gas occupies 22.4dm3 at s.t.p]
پاسخ دهید
(B)
0.896dm 3
20
Helium is preferred to hydrogen in filling balloons because hydrogen
پاسخ دهید
(A)
is inflammable
21
30cm3 pf hydrogen at s.t.p combine with 20cm3 of oxygen to form steam according to the following equation 2H2(g) + O2(g) → 2H2O(g).
Calculate the total volume of the gaseous mixture at the end of the reaction
پاسخ دهید
(B)
35cm3
22
An exothermic reaction is one which involves
پاسخ دهید
(B)
loss of heat to the surrounding
23
Which of the following is an acid salt?
پاسخ دهید
(D)
NaHCO3
24
Which of the following compounds dissolves in water to form a solution with pH below 7?
پاسخ دهید
(C)
Ammonium chloride
25
If the solubility of KHCO3 is 0.40 mole dm-3 at room temperature , calculate the mass of KHCO3 in 100dm3 of the solution at this temperature. [KHCO3 = 100hmol]
پاسخ دهید
(A)
4.0g
26
The property of calcium chloride which makes it useful as a drying agent is that it is
پاسخ دهید
(B)
deliquescent
27
Which of the following lowers the activation energy of a chemical reaction?
پاسخ دهید
(D)
Catalyst
28
Consider the reaction represented by the following equation: H2(g) + 12(g) → 2HI(g). The number of effective collisions of molecules of the reactants decreases as
پاسخ دهید
(C)
the volume of the system is increased
29
What will be the effect of increase in pressure on the following system at equilibrium? 2NH2(g) N2(g) + 3H2(g)
پاسخ دهید
(C)
the concentration of ammonia will increase
30
Which of the following is not correct about oxidation number convention? The oxidation number of a/an
پاسخ دهید
(D)
atom of a diatomic molecules is + 2
31
Equal volumes of water were added to one mole of each of the following compounds. Which of them produced the largest number of ions
پاسخ دهید
(B)
Sodium trioxonitrate (V)
32
When dilute copper (ll) chloride solution is electrolysed, the reaction at the cathode is represented by the equation
پاسخ دهید
(B)
Cu2+ + 2e- → Cu
33
How many carbon atoms are present in one molecule of 2-methylpropane?
پاسخ دهید
(C)
4
34
Which of the following is the most reactive towards bromine?
پاسخ دهید
(C)
Ethyne
35
Which of the following compounds is unsaturated?
پاسخ دهید
(C)
Methylbenzene
36
Which of the following compounds reacts with sodium hydroxide to form a salt?
پاسخ دهید
(A)
CH 3CH 2COOH
37
Alkanoates are produced from alkanols by
پاسخ دهید
(D)
esterification
38
Which of the following is a secondary alkanol?
پاسخ دهید
(C)
CH 3-CH(OH)-CH 3
39
Geometric (cis-trans) isomerism is exhibited by
پاسخ دهید
(A)
C 2H 2CI 2
40
Which of the following is needed to produce slag during the extraction of iron in the blast furnace?
