The major ingredient $(51 \%)$ in Portland cement is

Which of the following alkaline earth metals is the most electropositive?

$Y$ $\xleftarrow{\Delta ,\, 205^\circ C}$ $CaSO_4 \cdot 2H_2O$ $\xrightarrow{\Delta ,\, 120^\circ C}$ $X$. $X$ and $Y$ are respectively

Which compound produces a paramagnetic acidic gas upon heating?

Which of the following metal carbides gives propyne or allylene upon hydrolysis?

Chemical $A$ is used for softening temporary hard water. $A$ reacts with sodium carbonate to produce caustic soda. When $CO_2$ is passed through the solution of $A$,it turns milky. What is the chemical formula of $A$?