Multiple Choice QuestionsIdentify the wrong statement in the following.
Amongst isoelectronic species, smaller the positive charge on the cation, smaller is the ionic radius
Amongst isoelectronic species, greater the negative charge on the anion, larger is the ionic radius
Atomic radius of the elements increases as one moves down the first group of the periodic table
Atomic radius of the elements increases as one moves down the first group of the periodic table
A.
Amongst isoelectronic species, smaller the positive charge on the cation, smaller is the ionic radius
The Atomic radius of the elements decreases across a period from left to right due to increasing in effective nuclear charge. On moving down a group, since, a number of shells increases, so atomic radius increases. Amongst isoelectronic species, ionic radius increases with increases in negative charge or decrease in positive charge.
Which one of the following pairs is isostructural (i.e., having the same shape and hybridization)?
[BCl3 and BrCl3]
[NH3 and NO3-]
[NF3 and BF3]
[NF3 and BF3]
D.
[NF3 and BF3]
If a number of bond pairs and lone pairs are same for the given pairs, they are isostructural.
Which of the following species contains three bond pairs and one lone pair around the central atoms?
H2O
BF3
NH2-
NH2-
D.
NH2-
pA and pB are the vapour pressure of pure liquid components, A and B, respectively of and ideal binary solution. If xA represents the mole fraction of component A, the total pressure of the solution will be
pA + xA(pB-pA)
pA + xA(pA-pB)
pB + xA(pB-pA)
pB + xA(pB-pA)
D.
pB + xA(pB-pA)
Total pressure,
pT =p'A +p'B
We know that,
p'A =pAxA
p'B = pBxB
substituting the values of p'A and p'B in eq. (i)
pT = pAxA +pBxB
[xA+xB =1
xA = 1-xB or xB = 1-xA]
=pAxA +pB (1-xA)
=pAxA +pB -pBxA)
pT = pB +xA (pA-pB)
Which one of the following statements regarding photochemical smog is not correct?
Carbon monoxide does not play any role in photochemical smog formation
Photochemical smog is an oxidising agent in character
Photochemical smog is formed through photochemical reaction involving solar energy
Photochemical smog is formed through photochemical reaction involving solar energy
D.
Photochemical smog is formed through photochemical reaction involving solar energy
Photochemical smog is formed in warm and sunny climate during day time by the action of sunlight on primary pollutants. It contains nitrogen oxides, ozone, PAN etc. , which are oxidising in nature. so, photochemical smog is an oxidising agent in character. it causes irritation in eyes and throat.
The pair of species with t he same bond order is
O22-, B2
O2+, NO+
NO, CO
NO, CO
A.
O22-, B2
Which one of the alkali metals, forms only the normal oxide, M2O on heating in air?
Rb
K
Li
Li
C.
Li
Li is the alkali metal which forms only normal oxide Li2O when heated in air.
2Li +1/2 O2 ---> Li2O
sodium, when heated in air forms peroxide while heavier alkali metals form superoxide as the major product.
A mixture of potassium chlorate, oxalic acid and sulphuric acid is heated. During the reaction which element undergoes a maximum change in the oxidation number?
S
H
Cl
Cl
C.
Cl
When a mixture of potassium chlorate, oxalic acid and sulphuric acid is heated, the following reaction occurs:
Thus, Cl is the element which undergoes a maximum change in the oxidation state.
When Cl2 gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from
zero to +1 and zero to -5
zero to -1 and zero to +5
zero to -1 and zero to +5
zero to -1 and zero to +5
B.
zero to -1 and zero to +5
When chlorine gas reacts with hot and concentrated NaOH solution, it disproportionates into Chloride (Cl-) and Chlorate (ClO3-) ions. 
In which of the following compounds, nitrogen exhibits highest oxidation state?
N2H4
NH3
N3H
N3H
C.
N3H
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