Ionization Enthalpy

Q.

Why is second ionisation enthalpy higher than first?

Q.

$I{P}_1$ and $I{P}_2$ of Mg are 178 and 348 k cal ${mol}^{-1}$. The energy required for the reaction Mg $\to$ ${Mg}^{2+}$ + 2$e^{-}$ is

1. 526 kcal .

2. 180 kcal .

3. 348 kcal .

4. 178 kcal.

Q.

Ionic compounds are formed most easily with

1. High electron affinity, low ionisation energy

2. High electron affinity, high ionisation energy

3. Low electron affinity, high ionisation energy

4. Low electron affinity, low ionisation energy

Q.

Which of the following shows biggest jump in II and III ionization energy:

1. 1$s^2$ 2$s^2$ 2$p^6$ 3$s^2$

2. 1$s^2$ 2$s^2$ 2$p^6$ 3$s^2$, 3$p^2$

3. 1$s^2$ 2$s^2$ 2$p^6$ 3$s^2$3$p^6$ , 4$s^2$4$p^2$

4. 1$s^2$ 2$s^2$

Q.

Which of the following transitions involves maximum amount of energy -

1. M-(g) =M(g)

2. M(g) =M+(g)

3. M+(g) =M2+(g)

4. M2+(g) = M3+(g)

Q.

The ionization enthalpies of Li and Sodium are 520 KJ/mole and 495 KJ/mole respectively. The energy required to convert all the atoms present in 7mg of Li vapours and 23 mg of Sodium vapours to their respective gaseous cations respectively are

1. 495 J, 520 J

2. 52 J, 49.5 J

3. 520 J, 495 J

4. 49.5 J, 52 J

Q.

Which among the following elements have lowest value of $I{E}_1$

1. Sn

2. Pb

3. Si

4. C

Q. Which of the following has minimum effective nuclear charge
1. K
2. Na
3. Cs
4. Li

Q.

Which of the following explanation is best for not placing hydrogen in either the group of alkali metals or halogens

1. None of the above

2. Hydrogen is much lighter element than the alkali metals or the halogens

3. The ionization energy of hydrogen is to high for group of alkali metals, but too low of halogen group

4. Hydrogen can form compounds with all other elements

Q. The number of oxygen atoms required to combinewith 14 g of nitrogen to form N_2O_3g when 80% ofnitrogen is converted into N_2O_3 is

Q.

$1\mathrm{g}$ of $\mathrm{Mg}$ atoms in the vapour phase absorbs$50.0\mathrm{kJ}$ of energy. Find the composition of ${\mathrm{Mg}}^{+2}$ formed as a result of absorption of energy. ${\mathrm{IE}}_1$ and${\mathrm{IE}}_2$ for $\mathrm{Mg}$ are $740$ and $1450$ ${\mathrm{kJmol}}^{-1}$ respectively?

Q. $I{E}_1$ and $I{E}_2$ of magnesium are $7.6\text{eV}$ and $15.0\text{eV}$ respectively. The amount of energy in $\text{kJ}$ needed to convert all the atoms of magnesium into $M{g}^{2+}$ ions present in $36\text{mg}$ of magnesium vapour will be:
[Given: $1\text{eV}=96.5{\text{kJ mol}}^{–1}$].

1. $3.27$
2. $1.62$
3. $2.18$
4. $2.51$

Q. $2^{nd}$ Ionization potential of Al would not be numerically the same as

1. $2^{nd}$ electron affinity of Al
2. $1^{st}$ ionization potential of $A{l}^{+}$
3. $2^{nd}$ electron affinity of $A{l}^{3+}$
4. $3^{rd}$ ionization potential of $A{l}^{-}$

Q. calculate number of ions present in 212 grams of sodium carbonate?

Q. Which of the following isoelectronic ions have lowest ionization energy?

1. $S^{2-}$
2. $C{l}^{-}$
3. $C{a}^{2+}$
4. $K^{+}$

Q. 23.Alpha particle of 6MeV energy is scattered back from a silver foil. Calculate the maximum volume in which the entire charge of the atom is supposed to be concentrated?

Q.

The first ionization potentials in electron volts of nitrogen and oxygen atoms are respectively given by

1. 14.6, 13.6

2. 13.6, 13.6

3. 14.6, 14.6

4. 13.6, 14.6

Q. Two p-block elements $x$ (outer configuration $n{s}^{2}n{p}^3$) and $z$ (outer configuration $n{s}^{2}n{p}^4$) occupy neighbouring positions in a period. Using this information which of the following is correct with respect to their ionization potential $I_x$ and $I_z$.

1. $I_x>I_z$
2. $I_z>I_x$
3. $I_z=I_x$
4. Relation between $I_x$ and $I_z$ is uncertain.

Q.

Electronegativity generally increases down the group from Top to bottom.

1. True

2. False

Q. Which of the following statements is not true regarding ionization energy?

1. Ionization energy of $L{i}^{+}$ is greater than $B{e}^{+}$
2. Second ionization energy of $O$ is greater than $N$
3. Ionization energy of $Ga$ is greater than that of $Al$
4. None of the above.

Q. What is the correct order of increasing second ionisation energies for the elements $Be,B,C,N$ and $F?$

1. $Be<C<B<N<F$
2. $F<C<B<N<Be$
3. $Be<B<C<N<F$
4. $Be<C<N<B<F$

Q. $I{P}_1$ and $I{P}_2$ of $Mg$ are 178 and 348 Kcal mol${}^{-1}$. The energy required for the reaction $Mg\to M{g}^{2+}+2e^{-}$ is

1. $+170Kcalmo{l}^{-1}$
2. $+526Kcalmo{l}^{-1}$
3. $-170Kcalmo{l}^{-1}$
4. $-526Kcalmo{l}^{-1}$

Q.

Correct orders of Ist I.P. are -

(i) Li < B < Be < C

(ii) O < N < F

(iii) Be < N < Ne

1. (i), (ii)

2. (ii), (iii)

3. (i), (iii)

4. (i), (ii), (iii)

Q. The second ionization energy is maximum for:

1. Boron
2. Beryllium
3. Magnesium
4. Silicon

Q. In PO43- ion, number of bond pairs and lone pairs of electrons on phosphorus atom respectively are

Q. the element having no neutron in the nucleus of its atom is

Q. 18.When an ionic compound produces, cation and anion attract each other and energy loses, here which energy of which how loses

Q.

$I{P}_1$ and $I{P}_2$ of Mg are 178 and 348 K cal ${mol}^{-1}$. The energy required for the reaction Mg $\to$ ${Mg}^{2+}$ + 2$e^{-}$ is

1. 435 K cal

2. 536 K cal

3. 635 K cal

4. 178 K cal

Q. Comment on each of the following observations:
(a) The mobilities of the alkali metal ions in aqueous solution are $L{i}^{+}<N{a}^{+}<K^{+}<R{b}^{+}<C{s}^{+}$.
(b) Lithium is the only alkali metal to form a nitride directly.
(c) $E^{\ominus }$ for $M^{2+}\left(aq\right)+2e^{-}\to M\left(s\right)$ (where $M=Ca,Sr$ or $Ba$) is nearly constant.

Q.

The ionization energy of nitrogen is more than that of oxygen because

1. Nitrogen has half filled p-orbitals

2. Nitrogen is left to the oxygen in the same period of the periodic table

3. Nitrogen contains less number of electrons

4. Nitrogen is less electronegative