An aqueous solution of $4.5 \ g$ oxalic acid $(H_2C_2O_4)$ is made up to $250 \ mL$. Calculate the volume of $0.1 \ N$ $NaOH$ required to neutralize completely $20 \ mL$ of this solution.

White phosphorus reacts with chlorine and the product hydrolyses in the presence of water. Calculate the mass of $HCl$ obtained by the hydrolysis of the product formed by the reaction of $62 \ g$ of white phosphorus with chlorine in the presence of water.

How much lime $(CaO)$ can be obtained by heating $200 \ kg$ of limestone which is $95 \%$ pure? ............... $kg$

Find the weight in grams of carbon monoxide $(CO)$ that contains the same number of oxygen atoms as are present in $22 \ g$ of carbon dioxide $(CO_2)$.

In a chemical reaction, the sum of the formula weights of all reactants is $274 \text{ u}$ and the atom economy is $50\%$. Calculate the formula weight of the desired product. (in $\text{ u}$)

When $1 \ L$ of $CO_2$ gas is heated with graphite,the volume of the resulting gas mixture at $STP$ is $1.5 \ L$. Calculate the number of moles of $CO$ gas produced at $STP$.