$A + 2B + 3C \rightleftharpoons AB_2C_3$. Reaction of $6.0 \ g$ of $A$,$6.0 \times 10^{23}$ atoms of $B$,and $0.036 \ mol$ of $C$ yields $4.8 \ g$ of compound $AB_2C_3$. If the atomic mass of $A$ and $C$ are $60$ and $80 \ amu$,respectively,the atomic mass of $B$ is .............. $amu$ (Avogadro no. $= 6 \times 10^{23}$)

Assume carbon burns according to the following equation:
$2C_{(s)} + O_{2(g)} \rightarrow 2CO_{(g)}$
When $12 \ g$ of carbon is burnt in $48 \ g$ of oxygen,the volume of carbon monoxide produced is $...... \times 10^{-1} \ L$ at $STP$ [nearest integer].
[Given: Assume $CO$ as an ideal gas,molar mass of $C = 12 \ g \ mol^{-1}$,molar mass of $O = 16 \ g \ mol^{-1}$,and molar volume of an ideal gas at $STP$ = $22.7 \ L \ mol^{-1}$]

$A$ mixture containing $64.0 \ g$ of $H_2$ and $64.0 \ g$ of $O_2$ is reacted so that water is formed as follows:
$2H_2 + O_2 \rightarrow 2H_2O$
Which of the following statements is/are correct?

Consider the following reaction:
$3 PbCl_2 + 2 (NH_4)_3 PO_4 \rightarrow Pb_3(PO_4)_2 + 6 NH_4 Cl$
If $72 \ mmol$ of $PbCl_2$ is mixed with $50 \ mmol$ of $(NH_4)_3 PO_4$,then the amount of $Pb_3(PO_4)_2$ formed is $......... \ mmol$. (nearest integer)

What is the number of moles of water molecules required to prepare $n$ moles of methane from $n$ moles of methyl magnesium iodide?

In a reaction $A + B_2 \rightarrow AB_2$,identify the limiting reagent,if any,in the following reaction mixtures:
$(i)$ $300$ atoms of $A + 200$ molecules of $B_2$
$(ii)$ $2 \ mol \ A + 3 \ mol \ B_2$
$(iii)$ $100$ atoms of $A + 100$ molecules of $B_2$
$(iv)$ $5 \ mol \ A + 2.5 \ mol \ B_2$
$(v)$ $2.5 \ mol \ A + 5 \ mol \ B_2$