Chemistry Physics Biology
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Which of the following p-block elements exhibits the highest oxidation state?
Anonymous Quiz
24%
N
31%
O
29%
F
16%
S
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Which p-block element is known for forming a variety of oxoacids and their salts, known as "polyoxoacids"?
Anonymous Quiz
27%
P
39%
N
19%
B
15%
Si
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What is the name of the red allotrope of phosphorus that is used in the production of safety matches?
Anonymous Quiz
33%
White phosphorus
30%
Black phosphorus
21%
Violet phosphorus
15%
Scarlet phosphorus
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Which p-block element is used in the manufacture of semiconductors and is a crucial component in the electronics industry?
Anonymous Quiz
46%
Si
25%
S
20%
Cl
9%
Xe
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Among the halogens, which one has the lowest boiling point?
Anonymous Quiz
27%
F
27%
Cl
23%
Br
23%
I
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What is the general trend in the acidity of oxides across the p-block elements from left to right in the periodic table?
Anonymous Quiz
37%
Increase
37%
Decrease
19%
Remains same
7%
Varies unpredictably
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Which p-block element is commonly used as a reducing agent in metallurgical processes, especially for the extraction of metals from their ores?
Anonymous Quiz
21%
P
38%
C
27%
O
14%
S
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What is the name of the most stable and common allotrope of sulfur?
Anonymous Quiz
20%
Orthorhombic sulfur
40%
Rhombic sulfur
29%
Monoclinic sulfur
11%
Octahedral sulfur
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Which p-block element is responsible for the distinctive color in fireworks displays?
Anonymous Quiz
24%
P
38%
Na
26%
Sr
11%
K
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The radioactive isotope of phosphorus, P-32, is used in molecular biology and biochemistry for
Anonymous Quiz
27%
X ray crystallography
38%
DNA sequencing
19%
Labeling proteins
16%
Determining cell membrane potentials
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The dissociation constant of a weak acid is 1 x 10 -4
In order to prepare a buffer solution with a pH = 5,
the [Salt]/[Acid] ratio should be
Anonymous Quiz
20%
4:5
42%
10:1
28%
5:4
11%
1:10
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A buffer solution is prepared in which the
concentration of NH3is 0.30 M and the
concentration of NH4+ is 0.20 M. If the equilibrium constant, Kb for NH3 equals 1.8 x 10 -5 what is the pH of this solution? (log 2.7 = 0.43)
Anonymous Quiz
18%
9.08
37%
9.43
33%
11.72
12%
8.73
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In a buffer solution containing equal concentration
of B- and HB, the Kb for B- is 10 -10, The pH of buffer
Anonymous Quiz
28%
10
42%
7
20%
6
10%
4
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Which of the following pairs constitutes a buffer?
Anonymous Quiz
18%
HCl and KCl
36%
HNO2 and NaNO2
27%
NaOH and NaCl
19%
HNO3 and NH4NO3
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On electrolysis of dil. sulphuric acid using platinum
(Pt) electrode, the product obtained at anode will be
Anonymous Quiz
30%
Hydrogen gas
38%
Oxygen gas
20%
H2S gas
12%
SO2 gas
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The number of Faradays (F) required to produce
20 g of calcium from molten CaCl, (Atomic mass of
Ca = 40 g mol) is
Anonymous Quiz
16%
1
51%
2
25%
3
8%
4
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During the electrolysis of molten sodium chloride, the time required to produce 0.10 mol of chlorine gas usinga current of 3 amperes is (in min)
Anonymous Quiz
19%
55
36%
110
31%
220
14%
330
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The number of electrons delivered at the cathode during electrolysis by a current of 1 ampere in 60 seconds is (charge on electron = 1.60 x 10-19 C)
Anonymous Quiz
27%
6 x 10 23
30%
6 x 10 20
36%
3.75 x 10 20
7%
7.48 x 10 23
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When 0.1 mol MnO4 -2 is oxidised, the quantity of electricity required to completely oxidise MnO4 -2to
MnO4 - is
Anonymous Quiz
22%
96500 C
51%
2 x 96500 C
19%
9650 C
7%
96.50 C
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