Question

Three moles of ${{B}_{2}}{{H}_{6}}$ are completely reacted with methanol. The number of moles of the boron-containing product formed is:

Answer 1

Hint: The boron family contains elements boron (B) which is non-metal, aluminum (Al), gallium (Ga), Indium (In), and Thallium (Tl) are metals. The general oxidation states are +3 or +1. Boron forms hydrides, oxides, and natural isotopes are Boron-10 and boron-11.

Complete step by step solution:
The atomic number of Boron is 5 with a stable oxidation state +3.
Boron has many chemical properties when it combines with oxygen in the air to form boron trioxide, which forms a thin stable layer that prevents further oxidation with oxygen.
Born forms hydrides which are diborane ${{B}_{2}}{{H}_{6}}$ . Most probably boron hydrides are used in the synthesis of organic compounds.
 Preparation of diborane industrially by the action of metal hydride with boron and can be obtained in small quantities by the reaction of iodine with sodium borohydride.
\[2NaB{{H}_{4}}+{{I}_{2}}\to 2NaI+{{H}_{2}}\]
Physical and chemical properties of diborane:
-Boranes are low thermal stability and colorless diamagnetic compounds.
-Diborane is extremely toxic.
-Diborane is sweet to smell at low temperatures.
-It liberates hydrogen gas with higher boranes at high temperatures.
-Diborane reacts with methyl alcohol to give trimethyl borate.
${{B}_{2}}{{H}_{6}}+C{{H}_{3}}OH\to 2B{{(OC{{H}_{3}})}_{3}}+6{{H}_{2}}$
From the above reaction, one mole of diborane reacts with methanol to form 2 moles of trimethyl borate as a product.

Hence, three moles of diborane reacts with 18 moles of methanol to form 6 moles of trimethyl borate as a product.

Note: Two $-B{{H}_{2}}$ groups are linked in diborane by two bridged hydrogens. In diborane, boron has not sufficient electrons to form normal covalent bonds, because B has only 12 valence electrons. Therefore, diborane has eight B-H bonds. The four-terminal B-H bonds are normal covalent bonds.