In the reaction $2H_2 + O_2 \to 2H_2O$,if $6 \ g$ of $H_2$ combines with $64 \ g$ of $O_2$,find the mass of the excess reagent left in $g$.

For a given unbalanced reaction, $MnO_2 + HCl \rightarrow MnCl_2 + H_2O + Cl_2$, which is the limiting reagent if the initial amount for each reactant is $100 \ g$? [Molar masses: $MnO_2 = 86.9 \ g/mol$; $HCl = 36.5 \ g/mol$]

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)

When $12 \ L$ of $H_2$ and $11.2 \ L$ of $Cl_2$ are mixed and allowed to react according to the equation $H_{2(g)} + Cl_{2(g)} \rightarrow 2HCl_{(g)}$,what is the final composition of the mixture?

Calculate the weight of $CaO$ formed in quintals when $10 \ g$ of $CaCO_3$ is heated with $4.4 \ g$ of $CO_2$.

Equal weights of $X$ (atomic weight $= 36$) and $Y$ (atomic weight $= 24$) are reacted to form the compound $X_2Y_3$. Which of the following is correct?