If the heat of combustion of methane is $-100 \ kJ/mol$,then calculate the heat evolved when $32 \ g$ of methane reacts with $32 \ g$ of oxygen. (in $kJ$)

Calculate the maximum possible heat which can be released if a $4 \ L$ aqueous solution is to be formed by mixing appropriate volumes of $2 \ M$ $NaOH$ and $3 \ M$ $H_2SO_4$ solution. Given $\Delta H_{\text{neutralisation, SA/SB}} = -14 \ kcal/mol$.

$CaCO_3 + 2HCl \to CaCl_2 + CO_2 + H_2O$. In this chemical reaction,what will be the amount of $CaCl_2$ produced when $10 \ g$ of calcium carbonate and $200 \ mL$ of $0.75 \ M$ $HCl$ are used? $.............. \ g$

If $5$ moles of $BaCl_2$ is mixed with $2$ moles of $Na_3PO_4$,the maximum number of moles of $Ba_3(PO_4)_2$ formed is $..........$ (Nearest integer)

When $35 \ mL$ of $0.15 \ M$ lead nitrate solution is mixed with $20 \ mL$ of $0.12 \ M$ chromic sulphate solution,$....... \times 10^{-5}$ moles of lead sulphate precipitate out. (Round off to the Nearest Integer).

When $81.0 \ g$ of aluminium is allowed to react with $128.0 \ g$ of oxygen gas,the mass of aluminium oxide produced in grams is $..........$ $(Nearest \ integer)$. Given: Molar mass of $Al$ is $27.0 \ g \ mol^{-1}$,Molar mass of $O$ is $16.0 \ g \ mol^{-1}$.