Chemical Properties of Boron Family

Q.

What are isoelectronic species and give examples?

Q. $AlC{l}_3\text{is covalent while}Al{F}_3$ is ionic. This can be justified on the basis of:

1. Valence-bond theory
2. Fajan's rule
3. Molecular-orbital theory
4. Hydration energy

Q. What is oxidation state?

Q.

Why does Mn in oxide exhibit higher oxidation state than fluoride?

Q.

what is the oxidation number of chlorine in bleaching powder?

Q.

State Fajans Rules , And Give Suitable Examples.

Q.

What is amphoteric nature?

Q.

Oxidation state of both carbons CH3CH2OH

Q. The maximum covlaency for boron and aluminium respectively are

1. 4 and 6
2. 6 for both
3. 4 for both
4. 6 and 4

Q.

Which of the following is least basic?

1. ${\left({\mathrm{CH}}_3\mathrm{CO}\right)}_2\mathrm{NH}$

2. $\left({\mathrm{CH}}_3\mathrm{CO}\right){\mathrm{NHC}}_2{\mathrm{H}}_5$

3. ${\left({\mathrm{C}}_2{\mathrm{H}}_5\right)}_3\mathrm{N}$

4. ${\left({\mathrm{C}}_2{\mathrm{H}}_5\right)}_2\mathrm{NH}$

Q.

Why does boron trifluoride behave as a Lewis acid?

Q.

Write reactions to justify amphoteric nature of aluminium.

Q.

What are electron deficient compounds? Are BCl3 and SiCl4 electron deficient species?

Q. Permanganate titration is not carried out in the presence of hydrochloric acid because

1. In acidic medium $KMn{O}_4$ does not react
2. $HCl$ get oxidised to $C{l}_2$
3. $HCl$ form complex compound with $Mn{O}_4^{-}$
4. None of the above

Q.

How do you determine the pH of citric acid?

Q. Why is sncl4 more covalent than sncl2

Q.

What is the difference between Germanium and silicon?

Q. Why there is no loss of exchange energy at d6 configuration? And if it is because the atoms are in ion form and thus they are present in aqueous medium (h2o) then also h20 is weak field ligand so electrons cant pair In it then why there is no loss of exchange energy in d6?

Q.

How can you explain higher stability of $BC{l}_3$ as compared to $TlC{l}_3$?

Q. In which of the following pairs the interatomic bond angle is ${109}^o{28}^{\prime },{120}^o$ respectively?

1. $N{H}_4^{+},B{F}_3$
2. $N{H}_3,B{F}_4^{-}$
3. $N{H}_2^{-},B{F}_3$
4. None of these

Q. Gem-dibromide is

1. $C{H}_{3}CB{r}_{2}C{H}_3$
2. $C{H}_{2}BrC{H}_{2}Br$
3. $C{H}_2\left(Br\right)C{H}_{2}C{H}_2$
4. None of these

Q. Among the species: $C{O}_2$, $C{H}_{3}CO{O}^{-}$, $CO$, $C{O}_3^{2-}$, $HCHO$ which has the weakest carbon-oxygen bond?

1. $C{O}_2$
2. $CO$
3. $C{O}_3^{2-}$
4. $C{H}_{3}CO{O}^{-}$

Q.

A sudden large jump between the values of second and third ionization energies of an element would be associated with the electronic configuration.

1. 1s², 2s² 2p⁶, 3s² 3p²

2. 1s², 2s² 2p⁶, 3s²

3. 1s², 2s² 2p⁶, 3s¹

4. 1s², 2s² 2p⁶, 3s² 3p¹

Q. Discuss the role of Lewis acids in the preparation of aryl bromides and chlorides in the dark.

Q.

If the electronic configuration of an element is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{2}4s^2,$ the four electrons involved in chemical bond formation will be ---------

1. $3p^{6}3d^2$
2. $3p^{6}4s^2$
3. $3d^{2}4s^2$
4. $3p^6$

Q.

Electronic configuration of an atom X is (2, 8, 7). It combines with another atom Y having electronic configuration (.., 1).

What type of bond will be formed between X and Y?

Q.

Are halogens reactive with water?

Q.

The compound AgF₂ is an unstable compound. However, if formed, the compound acts as a very strong oxidizing agent. Why?

Q.

Heating ammonium cyanate to produce urea is an example of what type of a chemical reaction ?

Q. What is the oxidation number of Cl3?