Multiple Choice QuestionsIn which of the following options the order of arrangement does not agree with the variation of the property indicated against it?
B<C<N<O (increasing first ionisation enthalpy)
I<Br<Cl<F(increasing electron gain enthalpy)
Li<Na<K<Rb (increasing metallic radius)
Li<Na<K<Rb (increasing metallic radius)
B.
I<Br<Cl<F(increasing electron gain enthalpy)
The electron gain enthalpy is defined as the energy released when an electron is added to a neutral gaseous atom to convert it into a negative ion. Large negative values of electron gain enthalpy indicate that it is easier to add an electron to an atom to convert it into an anion, and hence large amount of energy is released. The electron gain enthalpies in halogens decreases in the order
Cl>F>Br>I
because as we proceed down a group because the size of the atom increases. Therefore the distance of the nucleus from the valence orbital (which accepts the additional electron) increases. Hence the force by which the additional electron is attracted by the nucleus also decreases and the electron gain enthalpies become less negative as we proceed down a group.
The species Ar, K+ and Ca2+ contain the same number of electrons. In which order do their radii increase?
Ar < K+< Ca2+
Ca2+ < Ar < K+
Ca2+ < K+ < Ar
Ca2+ < K+ < Ar
Solubility of the alkaline earth's metal sulphates in water decreases in the sequence
Mg>Ca>Sr>Ba
Ca>Sr>Ba>Mg>
Sr>Ca>Mg>Ba
Sr>Ca>Mg>Ba
The number of d- electrons in Fe2+ (Z = 26) is not equal to the number of electrons in which one of the following?
S- electronic in Mg (Z=12)
p-electrons in Cl( Z=17)
d- electrons in Fe (Z=26)
d- electrons in Fe (Z=26)
which of the following orders of ionic radii is correctly represented?
H- > H >H+
Na+ >F- >O2-
F- > O2->Na+
F- > O2->Na+
Identify 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
Which of the following represents the correct order of increasing electron gain enthalpy with negative sign for the elements O, S, F and Cl?
Cl < F < O < S
O < S < F< Cl
F < S < O < Cl
F < S < O < Cl
Which of the following pairs has the same size?
Fe2+ , Ni2+
Zr4+, Ti4+
Zr4+, Hf4+
Zr4+, Hf4+
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