The following atoms of carbon 126C, 136C and 146C can be described as?
Απάντηση
(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?
Απάντηση
(A)
136X
3
How many electrons are present in \(^9_4Be^{2+}\)?
Απάντηση
(A)
2
4
When element \(_{20}\)Y combines with element \(_8\)Z, it forms
Απάντηση
(C)
An ionic compound, YZ is formed
5
The boiling points of HF, H2O and NH3 increase in the order of
Απάντηση
(D)
NH3 < HF < H2O
6
Chemicals that are produced in small quantities and with very degree of purity are
Απάντηση
(B)
Fine chemicals
7
The mass of potassium hydroxide required to make 300.ocm3 of 0.4 moldm-3 solution is {KOH = 56.0}
Απάντηση
(C)
6.72g
8
Metals can be stretched into wires because they are
Απάντηση
(A)
Ductile
9
Aluminium is used in the manufacture or aircraft because it
Απάντηση
(B)
Is light and resists corrosion
10
An unsaturated solution differs from a saturated solution at a given temperature because it
Απάντηση
(C)
Can still dissolve more solute at given temperature
11
Which of the following arrangements shows increasing order of reactivity of the halogens?
Απάντηση
(B)
I2 < Br2 < Cl2< F2
12
The shape of the water molecule is_______?
Απάντηση
(D)
V-shaped
13
Which of the following elements would produce coloured ion in agueous solution?
Απάντηση
(B)
Copper
14
The minimum amount of energy required for effective collisions between reacting particles is known as
Απάντηση
(A)
Activation energy
15
The bond formed between H2O and H+ to form the hydroxonium H3O+ is
Απάντηση
(A)
Dative
16
An element X froms the following oxides X2O, XO and XO2. This phenomenon illustrates the law of________?
Απάντηση
(D)
Multiple proportion
17
How many moles of oxygen would contain 1.204 x 1024 molecules?
[Avogadro's constant (NA) = 6.02 x 1023]
Απάντηση
(B)
2
18
Which of the following statements about solids is correct?
Απάντηση
(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?
Απάντηση
(D)
Pipette
20
The general gas equation \(\frac{PV}{T}\) = K is a combination of
Απάντηση
(A)
Boyle's and Charles' laws
21
The spreading of the scent of a flower in a garden is an example of_____?
Απάντηση
(B)
Diffusion
22
Propane carbon(IV)oxide diffuse at the same rate because [H = 1.00, C = 12.0, O = 16.0]
Απάντηση
(C)
They have the same relative molecular mass
23
The energy which accompanies the addition of an electron to an isolated gaseous atom is
Απάντηση
(C)
Electron affinity
24
An aqueous solution of (NH4)2 SO4 is
Απάντηση
(A)
Acidic
25
When NH4Cl(s) is dissolved in water, the container feels cold to touch. This implies
Απάντηση
(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?
Απάντηση
(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
Απάντηση
(C)
Neutralization
28
The refreshing characteristic taste of fizzy drinks is due ot the presence of
Απάντηση
(A)
Carbon(IV)oxide
29
Chemical equilibrium is attained when
Απάντηση
(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
Απάντηση
(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]
Απάντηση
(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?
Απάντηση
(B)
NH4Cl
33
Which of the following bonds are broken when ethanol is boiled?
I. Covalent bonds
II. Ionic bonds
III. Hydrogen bonds
Απάντηση
(C)
III only
34
A compound with molecular formula CH2O2 is
Απάντηση
(B)
A Carboxylic acid
35
The quality of electricity required to discharge 1 mole of univalent ion is
Απάντηση
(C)
96500C
36
Chlorine water is used as a bleaching agent because it is
Απάντηση
(C)
An oxidizing agent
37
Which of the following substances is a non-electrolyte?
Απάντηση
(C)
C6H12O6
38
The oxidation number of sulphur is +4 in
Απάντηση
(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_______?
Απάντηση
(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
Απάντηση
(C)
2Al(s) + 3Cu2+(aq) \(\to\) 3Cu(s) + 2Al3+(aq)
41
Amino acids are obtained from proteins by
Απάντηση
(A)
Hydrolysis
42
When a compound X is heated with concentrated tetraoxosulphate(VI)acid, it produces an alkene. X is an
Απάντηση
(B)
Alkanol
43
Ripening of fruits is hastened by using
Απάντηση
(C)
Ethene
44
The compound that makes palm wine taste sour after exposure to the air for few days is
Απάντηση
(A)
Ethanol
45
Which of the following compounds is/are secondary alkanols?
