Which of the following scientists discovered the neutron?
Відповідь
(C)
James Chadwick
2
How many protons does 4020Ca contain?
Відповідь
(A)
20
3
If 100 atoms of element X contains 70 atoms of 9X and 30 atoms of 11X, calculate the relative atomic mass of X
Відповідь
(A)
9.6
4
Consider the reaction represented by the equation: 23892U + 10 → 13956Ba + 9436Kr + 310n. The reaction represents a
Відповідь
(A)
nuclear fission
5
How many orbitals are associated with the p-sub energy level?
Відповідь
(B)
3
6
Which of the following elements has the electronic configuration:1s22s22p63s23p1? [11Na, 13A1, 14N,16S]
Відповідь
(A)
Al
7
The following properties are characteristics of transition elements except
Відповідь
(B)
fixed oxidation states
8
Which of the following ions is isoelectronic with neon? [\(_3\)Li, \(_9\)F, \(_{10}\)Ne, \(_{17}\)CI,\(_{19}\)K ]
Відповідь
(B)
F-
9
Which of the following electronic configurations correctly represents an element in period 3 of the periodic table?
Відповідь
(C)
1s2 2s2 2p6 3s2 3p4
10
An element Q forms a compound QCI5. In which group of the periodic table is Q?
Відповідь
(C)
V
11
Which of the statements about the behaviour of the atom is correct?
Відповідь
(D)
cations are smaller than the parent atom
12
Which of the following properties of covalent compounds is not correct? They
Відповідь
(D)
have high boiling points
13
Which of the following arrangements is in order of increasing ionization energy?
Відповідь
(A)
AI, Si, P, S
14
In bonded atoms, increase in electronegativity difference,
Відповідь
(A)
increases polarity
15
Which of the following molecules is not linear in shape?
Відповідь
(C)
NH3
16
The number of particles in one mole of a chemical compound is the
Відповідь
(B)
avogadro's number
17
How many molecules are there in 14 g of nitrogen at s.t.p.? [N = 14, Avogadro's constant = 6.02 x 10\(^{23}\) mol-1]
Відповідь
(B)
3.01 x 1023
18
Consider the reaction represented by the equation: 2NaHCO3 → Na2CO 3 + H 2O + CO 2. What is the mass of sodium trioxocarbonate (lV) produced by the complete decomposition of 33.6 g of sodium hydrogen trioxocarbonate (IV)? [NaHCO3 = 84, Na2CO3 = 106]
Відповідь
(C)
21.2 g
19
What is the percentage by weight of calcium in Ca(OCI)2? [Ca = 40, Cl = 35.5, O = 16]
Відповідь
(A)
28.0%
20
What is the value of -14oC on the Kelvin temperature scale?
Відповідь
(A)
259K
21
Which of the following expressions correctly represents Charles' law?
Відповідь
(D)
V = KT
22
In a mixture of gases which do not react chemically together, the pressure exerted by the individual gases is called
Відповідь
(B)
partial pressure
23
In a chemical reaction, ∆H is positive when
Відповідь
(A)
H (product) >H (reactant)
24
Consider the reaction represented by the following equation: H 2(g) + \(\frac{1}{2}\) O(g) → H 2O(g) ∆H =-285.8 KJmo -1 ∆H represents the enthalpy of
Відповідь
(A)
formation
25
Salts that contain water of crystallization are said to be
Відповідь
(D)
hydrated
26
Which of the following dilute acids does not react with metals to liberate hydrogen?
Відповідь
(D)
HNO3(aq)
27
Which of the following compounds is not a double salt?
Відповідь
(A)
Zn(OH)NO3
28
Which of the following hydroxides will readily dissolved in water?
Відповідь
(B)
NaOH
29
Which of the following acids from normal salt only?
Відповідь
(C)
Trioxonitrate (V) acid
30
A solution that contains as much solute as it can dissolve at a given temperature is said to be
Відповідь
(B)
saturated
31
Which of the following salts is insoluble in water?
Відповідь
(D)
AgCI.
32
Which of the following statement is correct? The solubility of
Відповідь
(B)
gases decreases with increase in temperature
33
A catalyst increases the rate of chemical reaction by
Відповідь
(B)
decreasing the activation energy of the reaction
34
Which of the following factors will affect the rate of the reaction represented by the equation? 2HCI(aq) + CaCO 3(s) → CaCI2(aq) + H2O (I) + CO2(g) l. Pressure ll. Concentration III. Nature of reactants IV. Temperature
Відповідь
(B)
ll, lll and IV only
35
Which of the following substances is the anode in the dry Leclanche cell ?
Відповідь
(D)
Zinc container
36
Consider the reaction represented by the equation: 2H2SO 4(aq0 + C(s) → 2H2O(l) + 2SO2(g) + CO 2(g) H2SO 4 is acting as
Відповідь
(B)
an oxidizing agent
37
Which of the following oxides of nitrogen has oxidation number of + 1?
Відповідь
(B)
N2O
38
The separation of petroleum fractions depends on the differences in their
Відповідь
(A)
boiling points
39
Which of the following raw materials is used in the plastic industry ?
Відповідь
(B)
Ethene
40
The product of the reaction between C 2H5OH and concentrated H2SO 4 at 170oC is
Відповідь
(D)
CH2 = CH 2
41
When protein is heated to a high temperature it undergoes
Відповідь
(B)
denaturation
42
What is the molecular formula of a compound with empirical CH2O and vapour density of 90? [H = 1, C = 12, O = 16]
Відповідь
(D)
C6H12O6
43
What is the product of the reaction between propene and 1 mole of hydrogen iodide?
Відповідь
(A)
CH3CHICH3
44
Ethanol reacts with excess acidified K2Cr 2O7 to produce
Відповідь
(C)
ethanoic acid
45
Dry hydrogen chloride when dissolved in methylbenzene
Відповідь
(C)
does not affect litmus paper
46
A consequence of global warming is
Відповідь
(B)
flooding
47
The major product in the solvay process is
Відповідь
(B)
Na 2CO 3
48
Which of the following alloys does not contain copper? l. Brass II. Bronze III. Steel
Відповідь
(C)
lll only
49
The electron configuration of carbon atom in its excited state is [ 6C]
Відповідь
(D)
1s 22s12px12py12pz1
50
The electron configuration of carbon atom in its excited state is [ 6C]
