When $20 \ g$ of $CaCO_3$ is treated with $20 \ g$ of $HCl$,the mass of $CO_2$ formed would be: (in $g$)

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 $kJ$)

Aluminium reacts with sulfuric acid to form aluminium sulfate and hydrogen. What is the volume of hydrogen gas in liters $(L)$ produced at $300 \ K$ and $1.0 \ atm$ pressure,when $5.4 \ g$ of aluminium and $50.0 \ mL$ of $5.0 \ M$ sulfuric acid are combined for the reaction?
(Use molar mass of aluminium as $27.0 \ g \ mol^{-1}, R = 0.082 \ atm \ L \ mol^{-1} \ K^{-1}$)

How many moles of lead $(II)$ chloride will be formed from a reaction between $6.5 \ g$ of $PbO$ and $3.2 \ g$ of $HCl$?

In a closed vessel at $STP$,$50 \, L$ of $CH_4$ is ignited with $750 \, L$ of air (containing $20 \% \ O_2$). The number of moles of $O_2$ remaining in the vessel on cooling to room temperature is closest to

$10 \, mL$ of $10 \, M$ $H_2SO_4$ is mixed with $100 \, mL$ of $1 \, M$ $NaOH$ solution. The resultant solution will be: