What is the normality of $1.5 \ M \ H_3PO_4$ (in $.5$)?

How many kilograms of $CaCO_3$ must be heated to obtain $56$ kilograms of $CaO$? [Atomic masses: $Ca = 40, C = 12, O = 16$]

When $1 \ L$ of $CO_2$ is heated with graphite,the volume of the gases collected is $1.8 \ L$. What will be the number of moles of $CO$ produced at $STP$?

The $\Delta H^o$ of combustion of $C_4H_{10(g)}$ is $-2650 \ kJ \ mol^{-1}$. The amount of heat evolved at constant pressure that can be obtained by burning $5.8 \ kg$ of $C_4H_{10}$ is approximately:

$x$ grams of calcium carbonate was completely burnt in air. The weight of the solid residue formed is $28 \,g$. What is the value of $x$ (in grams)?

How many $g$ of $KOH$ are required to completely neutralize $12.6 \, g$ of $HNO_3$?