Which of the following is most acidic
$N{a_2}O$
$MgO$
$A{l_2}{O_3}$
$CaO$
For purification of alumina, the modern processes most useful when $(i)$ the impurity present is a lot of iron oxides and $(ii)$ the impurity present is a lot of silica, are
Assertion : Atomic radius of gallium is higher than that of aluminium
Reason : The presence of additional $d-$ electron offer poor screening effect for the outer electrons from increased nuclear charge.
Give uses of $Al$ and its compound.
Identify the compounds $A, X$ and $Z$ in the following reactions :
$A + 2HCl + 5{H_2}O \to 2NaCl + X$
$X\xrightarrow[{370\,K}]{\Delta }HB{O_2}\xrightarrow[{ > 370\,K}]{\Delta }Z$
Choose the correct sequence for the geometry of the given molecules Borazone, Borazole, $B_3O_6^{-3}$ , $Fe_2Cl_6$, trimer of $FCN$. [$'P'$ stands for planar and $'NP'$ stands for non-planar]