Which of the following is formed when calcium combines with oxygen?

Production of iron in a blast furnace follows the following equation:
$Fe_{3}O_{4(s)} + 4CO_{(g)} \rightarrow 3Fe_{(s)} + 4CO_{2(g)}$
When $4.640 \ kg$ of $Fe_{3}O_{4}$ and $2.520 \ kg$ of $CO$ are allowed to react,the amount of iron (in $g$) produced is $....$
[Given: Molar Atomic mass $(g \ mol^{-1}): Fe = 56, O = 16, C = 12$]

What is the maximum amount of $Cl_2$ gas produced when $1 \, g$ of $HCl$ and $1 \, g$ of $MnO_2$ are heated together (in $, g$)?

When $22.4 \ L$ of $H_{2(g)}$ is mixed with $11.2 \ L$ of $Cl_{2(g)}$,each at $S.T.P.$,the moles of $HCl_{(g)}$ formed is equal to

How many moles of $P_4$ can be produced by reaction of $0.10 \ mol$ $Ca_5(PO_4)_3F$,$0.36 \ mol$ $SiO_2$,and $0.90 \ mol$ $C$ according to the following reaction?
$4Ca_5(PO_4)_3F + 18SiO_2 + 30C \to 3P_4 + 2CaF_2 + 18CaSiO_3 + 30CO$

An electric discharge is passed through a mixture containing $50 \, c.c.$ of $O_2$ and $50 \, c.c.$ of $H_2$. The volume of the gases formed $(i)$ at room temperature and $(ii)$ at $110 \, ^oC$ will be