The function of fluorspar in the electrolytic reduction of alumina dissolved in fused cryolite $(Na_3AlF_6)$ is :
as a catalyst
to lower the temperature of melt and to make the fused mixture very conducting
to decrease the rate of oxidation of carbon anode
none of the above
Which is true for an element $R$ present in III group of the periodic table
Given below are two statements :
Statement $I:$ Upon heating a borax bead dipped in cupric sulphate in a luminous flame, the colour of the bead becomes green.
Statement $II:$ The green colour observed is due to the formation of copper(I) metaborate.
In the light of the above statements, choose the most appropriate answer from the options given below :
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.
The incorrect statement regarding above reactions is
$\mathop {Al}\limits_{metal} \xrightarrow[{(aq.)}]{{HCl}}'X' + Gas\,'P'$
$\mathop {Al}\limits_{metal} \xrightarrow[{ + {H_2}O}]{{NaOH\,(aq.)}}'Y' + Gas\,'Q'$
Anhydrous $AlC{l_3}$ cannot be obtained from which of the following reactions