Which is true about $H_3BO_3$
Soluble in water at low temperature
Tribasic acid
Forms when borax react with a base
None
Which of the following is formed when aluminium oxide and carbon is strongly heated in dry chlorine gas
Give origin of group $13$ elements
Give oxidation state of gallium.
Aluminium trifluoride is insoluble in anhydrous $HF$ but dissolves on addition of $NaF$. Aluminium trifluoride precipitates out of the resulting solution when gaseous $BF_3$, is bubbled through. Give reasons.
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.