Colour of Lanthanides

Q. Which of the following metal ions is colourless in water?

1. $V^{2+}$
2. $C{r}^{3+}$
3. $F{e}^{2+}$
4. $S{c}^{3+}$

Q. The colour of $\left[Ti\right(H_{2}O{)}_6{]}^{+3}$ is due to _________

1. Metal to Ligand Charge Transfer
2. Ligand to metal Charge Transfer
3. d-d
4. None of the above

Q. The lanthanide that would show colour is:

1. $G{d}^{3+}$
2. $L{a}^{3+}$
3. $L{u}^{3+}$
4. $S{m}^{3+}$

Q. Generally transition elements and their salts are colored due to the presence of unpaired electrons in metal ions. Which of the following compounds are colored?

1. $KMn{O}_4$
2. $Ce(S{O}_4{)}_2$
3. $TiC{l}_4$
4. $C{u}_{2}C{l}_2$

Q. Which of the following ions is coloured in solution?

1. $Z{n}^{2+}$

2. $T{i}^{4+}$

3. $C{u}^{+}$

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

Q. Which of the following pair of compounds is expected exhibit same colour in aqueous solution?

1. $FeC{l}_2,CuC{l}_2$
   

2. $VOC{l}_2,CuC{l}_2$

3. $VOC{l}_2,FeC{l}_2$
   

4. $FeC{l}_2,MnC{l}_2$

Q. Which of the following ions can form coloured compounds?

1. $S{c}^{3+}$
2. $Z{n}^{2+}$
3. $T{i}^{4+}$
4. $F{e}^{2+}$

Q. The lanthanide that would show colour is:

1. $G{d}^{3+}$
2. $L{a}^{3+}$
3. $L{u}^{3+}$
4. $S{m}^{3+}$

Q. Which of the following cations is detected by the flame test?

1. $N{H}_4^{+}$
2. $M{g}^{2+}$
3. $A{l}^{3+}$
4. $C{a}^{2+}$

Q. What is the number of pairs of ion which are coloured in aqueous solution?

$\left(i\right)T{i}^{3+},V^{3+}\left(ii\right)C{u}^{+},S{c}^{3+}\left(iii\right)F{e}^{2+},F{e}^{3+}\left(iv\right)C{o}^{2+},N{i}^{2+}\left(v\right)Z{n}^{2+},A{g}^{+}$

1. 3

2. 4

3. 5
4. 2

Q. Among the given ions in aqueous solution, $Z{n}^{2+},N{i}^{2+}$ and $C{r}^{3+}$ (atomic number $Zn=30,Ni=28,Cr=24$):

1. Only $Z{n}^{2+}$ is colourless and $N{i}^{2+}$ and $C{r}^{3+}$ are coloured
2. All three are colourless
3. All three are coloured
4. Only $N{i}^{2+}$ is coloured and $Z{n}^{2+}$ and $C{r}^{3+}$ are colourless

Q. Which of the following compound is soluble in water?

Q. The colour of light absorbed by an aqueous solution of $CuS{O}_4$ is:

1. yellow
2. violet
3. orange-red
4. blue-green

Q. The ${71}^{st}$ electron of an element $X$ with an atomic number of $71$ enters into the orbital:

1. $4f$
2. $6p$
3. $5d$
4. $6s$

Q. Generally transition elements and their salts are colored due to the presence of unpaired electrons in metal ions. Which of the following compounds are colored?

1. $KMn{O}_4$
2. $Ce(S{O}_4{)}_2$
3. $TiC{l}_4$
4. $C{u}_{2}C{l}_2$

Q.

What is the colour of $CuS{O}_4.5H_{2}O$?

1. Black
2. Blue
3. Green
4. Brown

Q. $F{e}^{3+}$ (aq.) reacts with aqueous KSCN to give a deep red solution due to the formation of $\left[Fe\right(SCN{)}^{2+}]$.

Q. When a reagent $\left(X\right)$ reacts with $F{e}^{3+}$, the solution turns red due to the formation of a compound $\left(Y\right)$. This reagent causes no change in color with $F{e}^{2+}$ in the pure state. Here $\left(X\right)$ and $\left(Y\right)$ are, respectively:

1. $N{H}_{4}SCN$ and $\left[Fe{\left(SCN\right)}_3\right]$
2. $K_4\left[Fe{\left(CN\right)}_6\right]$ and $F{e}_4{\left[Fe{\left(CN\right)}_6\right]}_3$
3. $K_3\left[Fe{\left(CN\right)}_6\right]$ and $K_{2}Fe{\left[Fe{\left(CN\right)}_6\right]}_3$
4. $N{a}_{2}HP{O}_4$ and $FeS{O}_4$

Q.

Q. Identify the correct pair of colorless species-

1. TiF₆^2- and Cu₂Cl₂
2. Cu₂Cl₂ and NiCl₄^2-
3. CoF₆^3- and NiCl₄^2-
4. TiF₆^2- and CoF₆^3-

Q. ${Cu}^{2+}$ gives white ppt of ${Cu}_2{I}_2$ with $KI$ and deep blue colour of $[{Cu\left({NH}_3\right)}_4{]}^{2+}$ with aq.${NH}_3$ (excess).

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

1. $S{c}^{3+}$
2. $F{e}^{2+}$
3. $T{i}^{3+}$
4. $M{n}^{2+}$

Q.

Give two tests for water.

Q. Intense blue colour of Prussian blue arises as a result of :

1. Electron transfer between $Fe\left(II\right)$ and $Fe\left(I\right)$
2. Electron transfer between $Fe\left(II\right)$ and $Fe\left(III\right)$
3. Ligand metal charge transfer
4. $d-d$ transition of electron

Q. In all its properties, hydrogen resembles:

1. halogens only
2. both alkali metals and halogens
3. alkali metals only
4. neither alkali metals nor halogens

Q. The colour of light absorbed by an aqueous solution of $CuS{O}_4$ is

1. Violet
2. Orange-red
3. Blue-green
4. Yellow

Q. In a sample of H-atoms, electrons make transitions from n = 5 to n =1. If all the special lines are observed, then the line having the third highest energy will correspond to :

1. 3 $\to$ 1
2. 5 $\to$ 4
3. 5 $\to$ 3
4. 4 $\to$ 1

Q. Electrons are getting added to an element Y :
is Y getting oxidized or reduced?