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