$Al_4C_3$ is an ionic carbide,named as

Match the constituents of cements with their percentage proportion :

Constituents	Percentage
$1$. $CaO$	$a$. $2-3\%$
$2$. $MgO$	$b$. $50-60\%$
$3$. $SiO_2$	$c$. $5-10\%$
$4$. $Al_2O_3$	$d$. $20-25\%$

For a good quality cement,the ratio of lime to the total of the oxides of $Si$,$Al$ and $Fe$ should be as close as to :

Which of the following does not dissolve in dil $H_2SO_4$?

$A$ mixture of sodium oxide and calcium oxide is dissolved in water and saturated with excess carbon dioxide gas. The resulting solution is ...... It contains ......... :

Match the following compounds with their respective uses:

Compound	Uses
$1. CaCO_3$	$a.$ In purification of coal gas
$2. Ca(OH)_2$	$b.$ As an antacid
$3. CaO$	$c.$ In paper and textile industries
$4. Na_2CO_3 \cdot 10H_2O$	$d.$ In glass and leather industries