Colour

Q.

Explain how transition elements form coloured compounds?

Q.

Predict which of the following will be coloured in aqueous solution? $T{i}^{3+},V^{3+},C{u}^{+},S{e}^{3+},M{n}^{2+},F{e}^{3+}$ and $C{o}^{2+}$. Give reasons for each.

Q. 27. The sum of coordination number and oxidation number of the metal M in the complex [M(en)2(C2O4)]Cl(where en is ethylenediamine)is 1)7 2)8 3)9 4)6

Q. Choose correct order of oxidizing power:-

1. VO₂⁺ < Cr₂O₇^2- < MnO4^-
2. Cr₂O₇^2-2⁺ < MnO₄^-
3. MnO₄^- < Cr₂O₇^2-+
4. VO₂⁺ < MnO₄^- < Cr₂O₇^2-

Q. Among $C{o}^{3+},T{i}^{2+},V^{2+}\text{and}C{r}^{2+}$ ions, one if used as
a reagent cannot liberate $H_2$ from dilute mineral acid solution, its spin-only magnetic moment in gaseous state is B.M. (Nearest integer)

Q. Calculate oxidation state of Cu in Cu(NO3)2?

Q.

Why are halogens coloured?

Q.

Ionic solids, which have anionic vacancies due to metal excess defect, develop colour. Explain with the help of a suitable example.

Q. Acidified potassium permanganate solution oxidises oxalic acid. The spin-only magnetic moment of the manganese product formed from the above reaction is B.M.
(Nearest Integer)

Q. Iron has the lowest oxidation state in

1. $K_4\left[Fe\right(CN{)}_6]$
2. $F{e}_2{O}_3$
3. $\left[Fe\right(CO{)}_5]$
4. $\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$

Q. The stability of peroxide and superoxide of alkali metals increases as we go down the group. Explain giving a reason.

Q. In $\left[B_4{O}_5\right(OH{)}_4{]}^{2-},$ the number of boron atoms having an octet of electron is:

1. $0$
2. $1$
3. $2$
4. $4$

Q.

Which among the following is colorless?

1. ${\mathrm{Sc}}^{2+}$

2. ${\mathrm{Zn}}^{2+}$

3. ${\mathrm{Ti}}^{3+}$

4. ${\mathrm{V}}^{3+}$

Q. Of the following outer electronic configurations of atoms, the highest oxidation state is achieved by which one of them

1. 
2. 
3. 
4. 

Q. Which ion gives coloured solution?

1. $Cu$
2. $Z{n}^{2+}$
3. $T{i}^{4+}$
4. $V^{3+}$

Q. Out of the following ions which one is colourless?

1. $S{c}^{3+}$
2. $T{i}^{3+}$
3. $V^{3+}$
4. $C{o}^{2+}$

Q. In a ccp crystal lattice, the edge length of the unit cell is $80pm$. Find the distance of tetrahedral void from the corner of a cube.

1. $64.72pm$
2. $90pm$
3. $45.5pm$
4. $34.64pm$

Q. Which of the following reaction(s) are feasible?

1. $F_2+2C{l}^{-}\to 2F^{-}+C{l}_2$
2. $C{l}_2+2F^{-}\to 2C{l}^{-}+F_2$
3. $B{r}_2+2I^{-}\to 2B{r}^{-}+I_2$
4. $C{l}_2+2B{r}^{-}\to 2C{l}^{-}+B{r}_2$

Q. Can I get an explanation on how NO in brown ring complex possess a +1 charge?

Q. Iron has the lowest oxidation state in

1. $K_4\left[Fe\right(CN{)}_6]$
2. $F{e}_2{O}_3$
3. $\left[Fe\right(CO{)}_5]$
4. $\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$

Q.

The magnetic moment of 'autocatalyst' formed in the reaction between acidified oxalic acid and potassium permanganate is

1. 5.9 BM
2. 4.9 BM
3. 3.9 BM
4. 2.8 BM

Q. Elements which generally exhibit multiple oxidation state and whose ions are usually coloured are

1. Metalloids
2. Transition elements
3. Non-metals
4. Gases

Q. Transition elements are coloured due to

1. Small size
2. Metallic nature
3. All
4. unpaired d – $e^{-}$

Q. In the following reaction sequence in aqueous solution, the species X, Y and Z, respectively, are

$S_2{O}_3^{2-}\stackrel{A{g}^{+}}{\to }\underset{\text{solution}}{\underset{\text{clear}}{X}}\stackrel{A{g}^{+}}{\to }\underset{\text{precipitate}}{\underset{\text{white}}{Y}}\stackrel{\text{with time}}{\to }\underset{\text{precipitate}}{\underset{\text{black}}{Z}}$

1. $\left[Ag\right(S_2{O}_3{)}_3{]}^{5-},A{g}_{2}S{O}_3,A{g}_{2}S$
2. $\left[Ag\right(S{O}_3{)}_2{]}^{3-},A{g}_2{S}_2{O}_3,Ag$
3. $\left[Ag\right(S{O}_3{)}_3{]}^{3-},A{g}_{2}S{O}_4,Ag$
4. $\left[Ag\right(S_2{O}_3{)}_2{]}^{3-},A{g}_2{S}_2{O}_3,A{g}_{2}S$

Q.

Illustrate the formation of oxide ion from oxygen atom.

Q. Explain why:
Transition elements form coloured compounds.

Q.

How do I prepare fresh ${\mathrm{FeSO}}_4$ ?

Q. The aqueous solution containing which one of the following ions will be colourless

1. 
2. 
3. 
4. 

Q. Which of the following is a colorless complex ion?

1. $\left[Cu\right(N{H}_3{)}_4{]}^{2+}$
2. $\left[Mn\right(H_{2}O{)}_6{]}^{3+}$
3. $\left[Cr\right(H_{2}O{)}_6{]}^{3+}$
4. $[Fe{F}_6{]}^{3-}$

Q.

Germanium or silicon becomes semiconductor due to

1. Chemical impurity

2. Schottky defect

3. Frenkel defect

4. Metal deficiency defect