The following atoms of carbon 126C, 136C and 146C can be described as?
отговор
(C)
Isotopes
2
An atom X consist of 6 protons, 6 electrons and 7 neutrons. Which of the following representations of the atom is correct?
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(A)
136X
3
How many electrons are present in \(^9_4Be^{2+}\)?
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(A)
2
4
When element \(_{20}\)Y combines with element \(_8\)Z, it forms
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(C)
An ionic compound, YZ is formed
5
The boiling points of HF, H2O and NH3 increase in the order of
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(D)
NH3 < HF < H2O
6
Chemicals that are produced in small quantities and with very degree of purity are
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(B)
Fine chemicals
7
The mass of potassium hydroxide required to make 300.ocm3 of 0.4 moldm-3 solution is {KOH = 56.0}
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(C)
6.72g
8
Metals can be stretched into wires because they are
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(A)
Ductile
9
Aluminium is used in the manufacture or aircraft because it
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(B)
Is light and resists corrosion
10
An unsaturated solution differs from a saturated solution at a given temperature because it
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(C)
Can still dissolve more solute at given temperature
11
Which of the following arrangements shows increasing order of reactivity of the halogens?
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(B)
I2 < Br2 < Cl2< F2
12
The shape of the water molecule is_______?
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(D)
V-shaped
13
Which of the following elements would produce coloured ion in agueous solution?
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(B)
Copper
14
The minimum amount of energy required for effective collisions between reacting particles is known as
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(A)
Activation energy
15
The bond formed between H2O and H+ to form the hydroxonium H3O+ is
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(A)
Dative
16
An element X froms the following oxides X2O, XO and XO2. This phenomenon illustrates the law of________?
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(D)
Multiple proportion
17
How many moles of oxygen would contain 1.204 x 1024 molecules?
[Avogadro's constant (NA) = 6.02 x 1023]
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(B)
2
18
Which of the following statements about solids is correct?
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(D)
Solid particles cannot be easily compressed
19
Which of the following apparatus can be used to measure a specific volume of a liquid accurately?
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(D)
Pipette
20
The general gas equation \(\frac{PV}{T}\) = K is a combination of
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(A)
Boyle's and Charles' laws
21
The spreading of the scent of a flower in a garden is an example of_____?
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(B)
Diffusion
22
Propane carbon(IV)oxide diffuse at the same rate because [H = 1.00, C = 12.0, O = 16.0]
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(C)
They have the same relative molecular mass
23
The energy which accompanies the addition of an electron to an isolated gaseous atom is
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(C)
Electron affinity
24
An aqueous solution of (NH4)2 SO4 is
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(A)
Acidic
25
When NH4Cl(s) is dissolved in water, the container feels cold to touch. This implies
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(A)
The process is endothermic
26
The pH of four solutions M,N,Q and R are 2,6,8 and 11 respectively.
Which of the following deductions about the solutions is correct?
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(A)
The pH of N is increased when the solution is diluted
27
Consider the following reaction equation
H3O+(aq) + OH(aq) \(\rightarrow\) 2H2O(1)
The reaction represents
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(C)
Neutralization
28
The refreshing characteristic taste of fizzy drinks is due ot the presence of
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(A)
Carbon(IV)oxide
29
Chemical equilibrium is attained when
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(C)
The concentration of reactants and products remain constant
30
Which of the following factors will affect the rate of the reaction represented by the following equation?
2HCl(aq) + CaCO3(s) \(\rightarrow\) CaCl2(aq) + H2O(1) + CO2(g)
I. Pressure
II.Concentration
III. Nature of reactants
IV. Temperature
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(B)
II, III and IV only
31
On evaporation to dryness, 350cm\(^3\) of saturated solution of salt Z gave 55.5g of salt. What is the solubility of the salt? [Z = 101]
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(A)
1.57 moldm-3
32
Which of the following salts when dissolved in water will form a solution that will change blue litmus to red?
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(B)
NH4Cl
33
Which of the following bonds are broken when ethanol is boiled?
I. Covalent bonds
II. Ionic bonds
III. Hydrogen bonds
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(C)
III only
34
A compound with molecular formula CH2O2 is
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(B)
A Carboxylic acid
35
The quality of electricity required to discharge 1 mole of univalent ion is
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(C)
96500C
36
Chlorine water is used as a bleaching agent because it is
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(C)
An oxidizing agent
37
Which of the following substances is a non-electrolyte?
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(C)
C6H12O6
38
The oxidation number of sulphur is +4 in
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(B)
H2SO3
39
Consider the following ionic equation:
Cr\(_2\)O\(_7\)\(^{2-}\) + 14H\(^+\) + ne- → 2Cr\(^{3+}\) + 7H\(_2\)O.
The value of n in the equation is_______?
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(B)
6
40
Consider the following half-cell reactions.
Al(s) \(\to\) Al3+(aq) + 3e-
Cu2+(aq) + 2e- \(\to\) Cu(s)
The overall equation for the reaction is
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(C)
2Al(s) + 3Cu2+(aq) \(\to\) 3Cu(s) + 2Al3+(aq)
41
Amino acids are obtained from proteins by
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(A)
Hydrolysis
42
When a compound X is heated with concentrated tetraoxosulphate(VI)acid, it produces an alkene. X is an
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(B)
Alkanol
43
Ripening of fruits is hastened by using
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(C)
Ethene
44
The compound that makes palm wine taste sour after exposure to the air for few days is
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(A)
Ethanol
45
Which of the following compounds is/are secondary alkanols?
