Q14.72P - Chemistry: Molecular Nature Of Matter And Change

Question

Give the name and symbol or formula of a Group 3A (13) element or compound that fits each description or use: 

(a) Component of heat-resistant (Pyrex-type) glass 

(b) Manufacture of high-speed computer chips 

(c) Largest temperature range for liquid state of an element 

(d) Elemental substance with three-center, two-electron bonds 

(e) Metal protected from oxidation by adherent oxide coat 

(f) Mild antibacterial agent (e.g., for eye infections) 

(g) Toxic metal that lies between two other toxic metals

Step-by-Step Solution

Answer

a) Boron is represented by B.

b) Gallium is represented by Ga.

c) Gallium is represented by Ga.

d) Boranes is represented by the chemical formula, $B{H}_3$ or $B_2{H}_6$

e) Aluminum is represented by Al.

f) Boric acid is represented by $H_{3}B{O}_3$

g) Thallium is represented by Tl. 

Step 1: Element used in heat resistant Pyrex glass

The element used in heat resistant Pyrex glass is boron. Generally, Pyrex glass is made up of borosilicates because of its strong chemical durability and temperature resistance. The chemical formula of boron is . Borosilicates are mixtures of silicon dioxide $\left(Si{O}_2\right)$, and boron trioxide $\left(B_2{O}_3\right)$.

Step 2: Element used in high speed computer chips

In computer chips, generally, silicon is used. But instead of silicon, gallium can also be used. Operation of gallium is faster than silicon semiconductors. Chemical formula of gallium is Ga.

Step 3: Element having largest temperature range in liquid state

Gallium in its liquid state has a very large temperature range. It has a temperature range of about $2000°C$. Its chemical formula is Ga.

Step 4: Elemental substance with 3 center, 2 electron bonds

Borane has three-center, two-electron bonds. The Group 3A element present in borane is boron. The chemical formula of borane is $B{H}_3$, while diborane is  in which $B - H - B$ bonds exist. So the compound with three-center, two-electron bonds is borane $\left(B_2{H}_6\right)$, and the element is boron (B).

Step 5: Metal protected from oxidation by adherent oxide coat

Aluminum, represented by Al, is the metal protected from oxidation by adherent oxide coat. It is protected by its oxide, aluminum oxide $\left(A{l}_2{O}_3\right)$.

Step 6: Element used as mild antibacterial agent

Several elements are used as mild anti-bacterial agents. But in Group 13, boron in boric acid is used as a mild antibacterial agent protecting from eye infections. It helps maintain the pH of the solution used for washing irritated eyes. 

Step 7: Toxic metal that lies between two other toxic metals

Thallium is the toxic metal that lies between two other toxic metals, i.e. lead and mercury. Lead and mercury are very toxic metals. Thallium is also toxic and causes gastrointestinal and neurological problems. Thallium is represented by Tl.