Reaction with Alkali: Properties, Electronic Configuration, Periodic Trends and Uses

It is through such a varied range of reactions of Group 13 elements with alkalis that there is an open window to the broad and new chemical nature that characterizes a group. Commonly known as the boron group, Group 13 consists of the elements boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl), all of which are, in most cases, readily apparent as free metallic objects, except for boron. Each of these bodies has peculiar physical and chemical properties, all of which are responsible for their reactions with alkalis; the study of such reactions is important for general, fundamental applications both in metal refining and in other areas of pioneering manufacture of modern, high technology materials, and in acquiring novel insights about the most fundamental of chemical laws. This paper will therefore discuss the physical properties of group 13 elements in relation to their reaction with alkalis and further investigate the kind of reactions the elements get into by noting the production of compounds and gases brought about. In addition, the paper also noted the relevance of these reactions in real-life situations and in research. Well, by the end of this chapter, you would have learned the reaction of group 13 elements with alkalis, and furthermore, what greater meaning this has in the chemical reactions that are taking place.

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This Story also Contains

1. Physical Properties of Group 13 – 2
2. Reaction with Alkalis
3. Applications in Real Life and Relevance in Academia
4. Recommended topic video on(Reaction with Alkali)
5. Summary

Physical Properties of Group 13 – 2

The physical properties of Group 13 also bear upon the chemical behavior of Group 13. However, from the perspective of bonding and structure more than the reactivity of the metal, it is clear that boron is less reactive compared to the other group 13 metals. Aluminum also forms a skin, like silicon, of oxide on its surface, hence not reacting with most substances readily. This includes the alkalis at normal temperatures. Thus, gallium, although it has its own distinctive set of properties, is useful principally for its ability to dilute, and hence reduce, the reactivity of aluminum, which has the potential for very widespread utility. Indium and thallium, though of somewhat less potential use in everyday applications, nevertheless are of practical use for certain designated industrial applications. Indium, being soft and ductile, finds high use in the world of electronics, for example. On the other hand, thallium is extremely dense, highly toxic, and used for specific purposes in fields, such as medical imaging.

Reaction with Alkalis

Group 13 elements react with alkalis to produce a number of different compounds having a range of properties. For example aluminum reacts with the common alkali, sodium hydroxide, to form sodium aluminate and hydrogen gas:
$[ 2Al + 2NaOH + 6H_2O \rightarrow 2Na[Al(OH)_4] + 3H_2 ]$

The amphoteric nature of the element aluminum is strongly reflected in this element's reaction with both acids and bases. Boron easily reacts with alkali to give borates, and many of those are very important in industry: for example, borax. The alkalis react with the gallium, indium, and thallium, though the chemical behavior in reactions is less well-known, and the interplay comes up less often in practical experience. So actually, such reactions have paramount importance for the chemical industries in refining metals and making semiconductors.

Fluorine in reaction with cold or hot alkali releases gases differently.
$2 \mathrm{~F}_2+2 \mathrm{NaOH} \rightarrow 2 \mathrm{NaF}+\mathrm{OF}_2+\mathrm{H}_2 \mathrm{O}$
(cold dilute)

$2 \mathrm{~F}_2+4 \mathrm{NaOH} \rightarrow 4 \mathrm{NaF}+\mathrm{O}_2+2 \mathrm{H}_2 \mathrm{O}$
(hot concentrated)

Other halogens form hypohalite with dilute NaOH and halate with conc. NaOH.
$\mathrm{X}_2(\mathrm{~g})+2 \mathrm{OH}^{-} \xrightarrow{ } \mathrm{X}^{-}+\mathrm{OX}^{-}+\mathrm{H}_2 \mathrm{O}$
(Hypohalite ion)

$\mathrm{X}_2(\mathrm{~g})+6 \mathrm{OH}^{-} \xrightarrow{70^{\circ} \mathrm{C}} 5 \mathrm{X}^{-}+\mathrm{XO}_3^{-}+3 \mathrm{H}_2 \mathrm{O}$
(Halate ion)

Applications in Real Life and Relevance in Academia

This is knowledge on the reactivity of Group 13 elements with alkalis, but it does not normally center in that classroom yet. Most industries exploit the reaction of aluminum with alkalis in very wide ranges of application. For instance, the Bayer process involves the refining of bauxite to obtain aluminum oxide, a raw material further processed to render the metal in its pure form. It also violently reacts with alkalis, forming borosilicate glass to a great extent, but not as exothermically as pure silicon. Therefore, this material's main applications are pyro-resistance and non-fractionability purposes in laboratory equipment and high-quality glassware. Applications based on such properties of gallium, such as its low melting point and its potential to form alloys with other metals, are important in the construction of electronics, especially semiconductors, and innovations like LEDs. On the other hand, the suppleness and malleability of indium can be exploited in making thin films it for touch screens and LCDs, and thallium can be used in some other advanced medical technologies.

These are reactions that state precisely how chemical element properties play an effective role in chemical interactions, in the view of an academic. It exhibits reflective basic properties: amphoterism, reactivity, and complex ion formation. In this way, the present study will find application in understanding some periodic trends and detailed principles better in inorganic chemistry.

Recommended topic video on(Reaction with Alkali)

Some Solved Examples

Example 1
Question: What products are expected from the disproportionation reaction of hypochlorous acid?

1) $\mathrm{HClO}_3$ and $\mathrm{Cl}_2 \mathrm{O}$
2) $\mathrm{HClO}_2$ and $\mathrm{HClO}_4$
3) HCl and $\mathrm{Cl}_2 \mathrm{O}$
4) $($ correct $) \mathrm{HCl}$ and $\mathrm{HClO}_3$

Solution:

Disproportionation of hypochlorous acid produces hydrochloric acid HCl and Chloric acid HClO_3. The reaction is given as

$3 \mathrm{HClO} \rightarrow 2 \mathrm{HCl}+\mathrm{HClO}_3$

Hence, the answer is the option (4).

Example 2
Question: Which is used for the purification of water.?

1)F₂

2) (correct)Cl₂

3)Br₂

4)I₂

Solution:

Solution

The property of Chlorine Cl₂ disproportionates in H₂O producing HCl and HOCl. The HOCl further releases nascent oxygen which leads to the purification of Water

$\begin{aligned} & \mathrm{Cl}_2+\mathrm{H}_2 \mathrm{O} \rightarrow \mathrm{HCl}+\mathrm{HOCl} \\ & \mathrm{HOCl} \rightarrow \mathrm{HCl}+[\mathrm{O}]\end{aligned}$

Hence, the answer is the option (2).

Example 3
Question: In a cold dilute basic medium Cl₂ is disproportionate to give

1) (correct) $\mathrm{Cl}^{-}$and $\mathrm{OCl}^{-}$
2) $\mathrm{Cl}^{-}$and $\mathrm{ClO}_3^{-}$
3) $\mathrm{Cl}^{-}$and $\mathrm{ClO}_4^{-}$
4) $\mathrm{ClO}^{-}$and $\mathrm{ClO}_3^{-}$

Solution:

Chlorine reacts with cold and dilute NaOH and undergoes disproportionation to form Chloride and Hypochlorite. The reaction is given as

$\mathrm{Cl}_2+2 \mathrm{NaOH} \rightarrow \mathrm{NaCl}+\mathrm{NaOCl}+\mathrm{H}_2 \mathrm{O}$

Hence, the answer is the option (1).

Summary

All these reactions of Group 13 elements with alkalis give sufficient information to characterize the physical and chemical properties of the elements of this particular group, starting from the weak reactivity of Boron, through the amphoteric nature of aluminum, to the special behavior of Gallium, Indium, and Thallium, all of which are of industrial and academic importance. The above relations can be explained only when the information is taken into account, which helps a better appreciation of the practical applicability and conceptual underpinning of the field of chemistry. It is this knowledge, which enlightens not only our ideas about the material world but also about informing the different technological and industrial upgradations.