In the electrolysis of alumina, cryolite is added to
Increase the melting point of alumina
Increase the electrical conductivity
Minimise the anodic effect
Remove impurities from alumina
Explain atomic radius of elements of boron family.
Aluminum dissolves in mineral acids and aqueous alkalis and thus shows amphoteric character. A piece of aluminum foil is treated with dilute hydrochloric acid or dilute sodium hydroxide solution in a test tube and on bringing a burning match stick near the mouth of the test tube, a pop sound indicates the evolution of hydrogen gas. The same activity when performed with concentrated nitric acid, reaction doesn't proceed. Explain the reason.
Borax in its crystal possess
Anhydrous aluminium chloride fumes in moist air owing to the formation of
When metal $X$ is treated with sodium hydroxide, a white precipitate $(A)$ is obtained, which is soluble in excess of $NaOH$ to give soluble complex $(B)$. Compound $(A)$ is soluble in dilute $HCl$ to form compound $(C)$. The compound $(A)$ when heated strongly gives $(D)$, which is used to extract metal. Identify $(X), (A), (B), (C)$ and $(D)$. Write suitable equations to support their identities.