Solubility in Ammonia (Group 1)

Q. Statement-1 : Alkali metals dissolve in liquid ammonia to give blue solutions.

Statement-2 : Alkali metals in liquid ammonia give solvated species of the type $\left[M\right(N{H}_3{)}_n{]}^{+}$ (M =alkali metals).

1. Statement-1 is True, Statement-2 is True; Statement-2 is Not a correct explanation for Statement-1

2. Statement-1 is True, Statement-2 is False

3. Statement-1 is False, Statement-2 is True

4. Statement-1 is True, Statement-2 is True ; Statement-2 is a correct explanation for Statement-1.

Q. What will the major product when ethyl chloride reacts with $KN{O}_2$ ?

1. Ethylnitrite
2. Nitroethane
3. Both ethylnitrite and nitroethane will be formed in equal quantities.
4. Ethyl nitrate

Q.

In the Lassaigne’s test for nitrogen in an organic compound, the Prussian blue colour is obtained due to the formation of:
(a) $N{a}_4\left[Fe\right(CN{)}_6]$ (b) $F{e}_4\left[Fe\right(CN{)}_6{]}^3$ (c) $F{e}_2\left[Fe\right(CN{)}_6]$ (d) $F{e}_3\left[Fe\right(CN{)}_6{]}_4$

Q.

What is the principle of absorption spectroscopy?

Q. Why dry ether is used in Wurtz reaction?

Q.

When sodium is dissolved in lequid ammonia, a solution of deep blue colour is obtained. The colour of the solution is due to
(a) ammoniated electron (b) sodium ion
(c) sodium amide (d) ammoniated sodium ion

Q.

Why Co (||) is stable in aqueous solution but in the presence of strong ligands it can get oxidized to Co (|||)?

Q.

When an alkali metal dissolves in liquid ammonia the solution can acquire different colours. Explain the reasons for this type of colour change.

Q.

Discuss the chemistry of Lassaigne’s test.

Q. Which of the following statements is not true about the dilute solutions of alkali metals in liquid ammonia ?

1. Ammoniated cation and solvated electrons are formed in the solution
2. They are deep blue coloured solutions
3. They are highly conductive in nature
4. They are diamagnetic in nature

Q. Explain the preparation of K2Cr2O7 from chromite ore and write the chemical equations involved?

Q. Which of the following metal(s) in liquid $N{H}_3$ with low concentration is paramagnetic?

1. Na
2. Cs
3. K
4. None of the above.

Q. Highly pure dilute solution of sodium in liquid ammonia
(IIT-JEE, 1998)

1. Shows blue colour
2. Exhibits electrical conductivity
3. Produces sodium anide
4. Produces hydrogen gas

Q. Identify the incorrect statement:

1. The oxidation state of chromium in $Cr{O}_4^{2–}\text{\&}C{r}_2{O}_7^{2–}$ are not the same.
2. $C{r}^{2+}$ is stronger reducing agent than $F{e}^{2+}$ in water
3. Interstitial compounds are those that are formed when small atoms like $H,CorN$ are trapped inside the crystal lattices of metals.
4. The transition metals and their compounds are known for their catalytic activity due to their ability to adopt multiple oxidation states and to form complexes.

Q. The metallic sodium disolves in liquid amonia to form a deep blue coloured solution. The deep blue colour is due to formation of.

1. solvated electron, $\left[\text{e}\right(N{H}_3{)}_y{]}^{-}$
2. $NaN{H}_2+H_2$
3. solvated atomic sodium, $Na(N{H}_3{)}_y$
4. $(N{a}^{+}+N{a}^{-})$

Q.

When a metal of group 1 was dissolved in liquid ammonia, the following observations were obtained

(i) Blue solution was obtained initially.

(ii) On concentrating the solution, Blue colour changed to bronze colour. How do you account fot hte blue colour of the solution? Give the name of the product formed on keeping the solution for some time.

Q. Choose the incorrect statement regarding alkali in liquid ammonia solution

1. On concentrating the solution, it gives copper bronze color
2. Increasing concentration decreases the conductivity of solution
3. Increasing concentration forms metal ion clusters
4. None of the above

Q. Highly pure dilute solution of sodium in liquid ammonia :

1. Shows blue colour
2. exhibits electrical conductivity
3. produce hydrogen gas on standing
4. None of the above.

Q.

State as to why

(a) a solution of Na₂CO₃ is alkaline ?

(b) alkali metals are prepared by electrolysis of their fused chlorides ?

(c) sodium is found to be more useful than potassium ?

Q. The pair(s) of reagents that yield paramagnetic species is/are
(JEE Advanced, 2014)

1. Na and excess of $N{H}_3$
2. K and excess of $O_2$
3. Cu and dilute $HN{O}_3$
4. $O_2$ and 2-ethylanthraquinol

Q. An organic compound containing nitrogen, sulphur, and oxygen as extra elements is fused with metallic sodium and then extracted with distilled water.
Which of the following species is/are present in the Lassaigne’s extract?

1. $N{O}_3^{-}$
2. $C{N}^{-}$
3. $[SCN{]}^{-}$
4. $S^{2-}$

Q. Assertion (A): $HN{O}_3$ makes iron passive.
Reason (R): $HN{O}_3$ forms a protective layer of ferric nitrate on the surface of iron.
Mark the correct choice as:
[1 Mark]

1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is NOT the correct explanation of A
3. A is true but R is false
4. A is false and R is True

Q.

In the Lassaigne’s test for nitrogen in an organic compound, the Prussian blue colour is obtained due to the formation of:

(a) Na₄[Fe(CN)₆] (b) Fe₄[Fe(CN)₆]₃ (c) Fe₂[Fe(CN)₆] (d) Fe₃[Fe(CN)₆]₄

Q. In which region of light the ammoniated electrons in the solution absorb energy?

1. Infrared
2. Ultraviolet
3. Visible
4. All of the above.

Q.

What is meant by 'doping' in a semiconductor?

Q. The gaseous product(s) expected by reaction of sodium borohydride and boron trifluoride under anhydrous conditions at high temperature is/are:

1. $H_2$
2. $B_2{H}_6$ and $H_2$
3. $B_2{H}_6$
4. $B{H}_{2}F$ and $H_2$

Q.

Highly pure dilute solution of sodium in liquid ammonia

1. Produces sodium amide

2. Shows blue colour

3. Exhibits electrical conductivity

4. Produces hydrogen gas

Q. A solution of sodium metal in liquid ammonia is strong reducing agent due to the presence of

1. Sodium atoms
2. Sodium Hydride
3. Sodium amide
4. Solvated electrons

Q. Catalyzed by iron, alkali metals dissolve in liquid ammonia to yield:

1. Metal amide

2. 

3. H₂

4. Iron hydride

Q.

State your observations when following salts are heated strongly in dry state. Write chemical equations in support of your answer.

Zinc nitrate hexahydrate $[\mathrm{Zn}{\left({\mathrm{NO}}_3\right)}_2.6{\mathrm{H}}_2\mathrm{O}]$