The following atoms of carbon 126C, 136C and 146C can be described as?
Одговорити
(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?
Одговорити
(A)
136X
3
How many electrons are present in \(^9_4Be^{2+}\)?
Одговорити
(A)
2
4
When element \(_{20}\)Y combines with element \(_8\)Z, it forms
Одговорити
(C)
An ionic compound, YZ is formed
5
The boiling points of HF, H2O and NH3 increase in the order of
Одговорити
(D)
NH3 < HF < H2O
6
Chemicals that are produced in small quantities and with very degree of purity are
Одговорити
(B)
Fine chemicals
7
The mass of potassium hydroxide required to make 300.ocm3 of 0.4 moldm-3 solution is {KOH = 56.0}
Одговорити
(C)
6.72g
8
Metals can be stretched into wires because they are
Одговорити
(A)
Ductile
9
Aluminium is used in the manufacture or aircraft because it
Одговорити
(B)
Is light and resists corrosion
10
An unsaturated solution differs from a saturated solution at a given temperature because it
Одговорити
(C)
Can still dissolve more solute at given temperature
11
Which of the following arrangements shows increasing order of reactivity of the halogens?
Одговорити
(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?
Одговорити
(B)
Copper
14
The minimum amount of energy required for effective collisions between reacting particles is known as
Одговорити
(A)
Activation energy
15
The bond formed between H2O and H+ to form the hydroxonium H3O+ is
Одговорити
(A)
Dative
16
An element X froms the following oxides X2O, XO and XO2. This phenomenon illustrates the law of________?
Одговорити
(D)
Multiple proportion
17
How many moles of oxygen would contain 1.204 x 1024 molecules?
[Avogadro's constant (NA) = 6.02 x 1023]
Одговорити
(B)
2
18
Which of the following statements about solids is correct?
Одговорити
(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?
Одговорити
(D)
Pipette
20
The general gas equation \(\frac{PV}{T}\) = K is a combination of
Одговорити
(A)
Boyle's and Charles' laws
21
The spreading of the scent of a flower in a garden is an example of_____?
Одговорити
(B)
Diffusion
22
Propane carbon(IV)oxide diffuse at the same rate because [H = 1.00, C = 12.0, O = 16.0]
Одговорити
(C)
They have the same relative molecular mass
23
The energy which accompanies the addition of an electron to an isolated gaseous atom is
Одговорити
(C)
Electron affinity
24
An aqueous solution of (NH4)2 SO4 is
Одговорити
(A)
Acidic
25
When NH4Cl(s) is dissolved in water, the container feels cold to touch. This implies
Одговорити
(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?
Одговорити
(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
Одговорити
(C)
Neutralization
28
The refreshing characteristic taste of fizzy drinks is due ot the presence of
Одговорити
(A)
Carbon(IV)oxide
29
Chemical equilibrium is attained when
Одговорити
(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
Одговорити
(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]
Одговорити
(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?
Одговорити
(B)
NH4Cl
33
Which of the following bonds are broken when ethanol is boiled?
I. Covalent bonds
II. Ionic bonds
III. Hydrogen bonds
Одговорити
(C)
III only
34
A compound with molecular formula CH2O2 is
Одговорити
(B)
A Carboxylic acid
35
The quality of electricity required to discharge 1 mole of univalent ion is
Одговорити
(C)
96500C
36
Chlorine water is used as a bleaching agent because it is
Одговорити
(C)
An oxidizing agent
37
Which of the following substances is a non-electrolyte?
Одговорити
(C)
C6H12O6
38
The oxidation number of sulphur is +4 in
Одговорити
(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_______?
Одговорити
(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
Одговорити
(C)
2Al(s) + 3Cu2+(aq) \(\to\) 3Cu(s) + 2Al3+(aq)
41
Amino acids are obtained from proteins by
Одговорити
(A)
Hydrolysis
42
When a compound X is heated with concentrated tetraoxosulphate(VI)acid, it produces an alkene. X is an
Одговорити
(B)
Alkanol
43
Ripening of fruits is hastened by using
Одговорити
(C)
Ethene
44
The compound that makes palm wine taste sour after exposure to the air for few days is
Одговорити
(A)
Ethanol
45
Which of the following compounds is/are secondary alkanols?
