Which of the anhydrous salts,when it comes in contact with water,turns blue?

Which one of the following metallic hydroxides does not dissolve in sodium hydroxide solution?

The two major constituents of Portland cement are

The incorrect order of solubility in water is

Compare the solubility and thermal stability of the following compounds of the alkali metals with those of the alkaline earth metals: $(i)$ Nitrates,$(ii)$ Carbonates,$(iii)$ Sulphates.

$A$ hydrated solid $X$ on heating initially gives a monohydrated compound $Y$. $Y$ upon heating above $373 \ K$ leads to an anhydrous white powder $Z$. $X$ and $Z$,respectively,are