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