Cationic Radius

Q.

Explain why cations are smaller and anions larger in radii than their parent atoms?

Q. $CsBr$ has bcc structure with edge lengths $4.3$. The shortest inter ionic distance$\left(\text{in pm}\right)$ in between $C{s}^{+}$ and $B{r}^{-}$ is: (Given, $\sqrt{3}=1.73$)

Q.

Compare ionic radio of Mg2+ and Li1+

Q.

Which of the following is largest?

1. Cl^-

2. Na⁺

3. S^2-

4. F^-

Q. Ellingham diagram represents the change in

1. $\Delta G$ with temperature
2. $\Delta H$ with temperature
3. $\Delta G$ with pressure
4. $\Delta S$ with temperature

Q. The sizes of following species increase in the order:

1. Mg²⁺ < Na⁺ < F^- < Al
2. F^- < Al < Na⁺ < Mg²⁺
3. Al < Mg²⁺ < F^- < Na⁺
4. Na⁺ < Al < F^- < Mg²⁺

Q.

The species $Ar,K^{+}andC{a}^{2+}$ contain the same number of electrons. In which order do their radii increase?

1. $C{a}^{2+}<Ar<K^{+}$

2. $K^{+}<Ar<C{a}^{2+}$

3. $C{a}^{2+}<K^{+}<Ar$

4. $Ar<K^{+}<C{a}^{2+}$

Q. A solid $AB$ has rock salt structure. If the edge lenght is $520pm$ and radius of $A^{+}$ is $80pm$, the radius of anion $B^{-}$ would be -

1. $440pm$
2. $220pm$
3. $360pm$
4. $180pm$

Q. $L{a}^{3+},G{d}^{3+}$ and $L{u}^{3+}$ have abnormally low third ionisation enthalpy values. Why? ​

1. Because of extra stability of $f^0,f^7$ and $f^{14}$ orbitals​
2. Because of lanthanide contraction
3. Because of decrease in ionic size
4. None of the above

Q. Q. Calculate the radius of first orbit of He+ ion.

Q.

Which of the following cations has the smallest radius?

1. Na⁺

2. K⁺

3. Be²⁺

4. Li⁺

Q. Which has lowest and highest first ionisation enthalpy in 3d series?

1. $Sc\text{and}Zn$
2. $Zn\text{and}Sc$
3. $Cu\text{and}Zn$
4. $Cr\text{and}Zn$

Q.

Of the following, the one with the largest size is?

1. Ar

2. K⁺

3. Ca²⁺

4. Cl^-

Q.

If the ionic radii of $K^{+}$ and $F^{-}$ are nearly the same (i.e $1.34\mathring{A}$) then the atomic radii of $K$ and $F$ are respectively are

1. $1.34\mathring{A},1.34\mathring{A}$

2. $0.72\mathring{A},1.96\mathring{A}$

3. $1.96\mathring{A},0.72\mathring{A}$

4. $1.96\mathring{A},1.34\mathring{A}$

Q. What is radius for an ion to occupy tetrahedral site

Q.

The radius of $N{a}^{+}$ cation is less than that of Na atom. Give reason.

Q. The size of the species $I,I^{-}$ & $I^{+}$ follows the order:

1. $I>I^{-}>I^{+}$
2. $I^{+}>I>I^{-}$
3. $I^{-}>I>I^{+}$
4. $I^{+}>I^{-}>I$

Q. Which of the following alkaline earth metal sulphates has hydration enthalpy higher than the lattice enthalpy?

1. $SrS{O}_4$
   
2. $CaS{O}_4$
   
3. $BeS{O}_4$
   
4. $BaS{O}_4$
   

Q. Which is the minimum values of $r_{+}/r_{-}$ needed to prevent anion-anion contact in $NaCl$ crystals?

1. $0.225$
2. $0.414$
3. $0.342$
4. $0.514$

Q.

$N{a}^{+}.M{g}^{2+},A{l}^{3+}$ and $S{i}^{4+}$ are isoelectronic. The order of their ionic size is

1. $N{a}^{+}<M{g}^{2+}>A{l}^{3+}>S{i}^{4+}$

2. $N{a}^{+}>M{g}^{2+}<A{l}^{3+}<S{i}^{4+}$

3. $N{a}^{+}>M{g}^{2+}>A{l}^{3+}>S{i}^{4+}$

4. $N{a}^{+}<M{g}^{2+}>A{l}^{3+}<S{i}^{4+}$

Q.

Which of the following is smallest in size?

1. ${\mathrm{N}}^{3-}$

2. ${\mathrm{O}}^{2-}$

3. ${\mathrm{F}}^{-}$

4. ${\mathrm{Na}}^{+}$

Q.

Explain why cations are smaller and anions larger in radii than their parent atoms?

Q.

Which one of the following is the correct order of increasing size?

1. $Mg<Na<F^{-}<Al$

2. $Na<Al<Mg<F$

3. $Na<F^{-}<Al<Mg$

4. $Na<F^{-}<Mg<Al$

Q.

The smallest among the following ions is

1. Na⁺

2. Mg⁺²

3. Ba²⁺

4. Al³⁺

Q.

Which of the following is correct regarding ionic radii?

1. Ti⁴⁺ < Mn⁺⁷

2. ₃₅Cl^- < ₃₇Cl^-

3. K⁺ > Cl^-

4. P³⁺ > P⁵⁺

Q. Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy ?

1. $CaS{O}_4$
2. $BeS{O}_4$
3. $BaS{O}_4$
4. $SrS{O}_4$

Q. The dipole moment of $HBr$ is $0.78\times {10}^{-18}$ esu-cm and bond length of $HBr$ is $1.41A^{\circ }$. The ionic character of $HBr$ is:

1. $7.5$
2. $27$
3. $15$
4. $11.52$

Q.

The size of species $I$, $I^{\oplus }$ and $I^{\ominus }$ decreases in the order

1. $I^{\oplus }>I^{\ominus }>I$

2. $I^{\ominus }>I>I^{\oplus }$

3. $I^{\ominus }>I^{\oplus }>I$

4. $I>I^{\oplus }>I^{\ominus }$

Q. $CsBr$ has a bcc type structure with edge length $4.3\text{pm}$. The shortest inter ionic distance between $C{s}^{+}$ and $B{r}^{-}$ is:

1. $3.72\text{pm}$
2. $1.86\text{pm}$
3. $7.44\text{pm}$
4. $4.3\text{pm}$

Q. $CsBr$ has a bcc type structure with edge length $4.3\text{pm}$. The shortest inter ionic distance between $C{s}^{+}$ and $B{r}^{-}$ is:

1. $3.72\text{pm}$
2. $1.86\text{pm}$
3. $7.44\text{pm}$
4. $4.3\text{pm}$