Calculate percentage atom economy when $46 \ g$ ethanol is obtained from $64.5 \ g$ chloroethane and $56 \ g$ $KOH_{(aq)}$. (in $\%$)

What volume of $0.1 \, M \, HCl$ in $cm^3$ is required to react completely with $1 \, g$ of pure calcium carbonate $(CaCO_3)$?

How many grams of $KClO_3$ must be decomposed to obtain $2.40 \, L$ of $O_2$ gas at $25 \, ^\circ C$ and $740 \, mm \, Hg$ pressure (in $, g$)? (Molar mass of $KClO_3 = 122.5 \, g \, mol^{-1}$)

To change the strength of $25 \, mL$ of $0.15 \, M$ $HCl$ to $0.1 \, M$,the quantity of water that is to be added is.......$mL$

The ratio of mass percentage (w/w) of $C : H$ in a hydrocarbon is $12 : 1$. It has two carbon atoms. The weight (in $g$) of $CO_2(g)$ formed when $3.38 \ g$ of this hydrocarbon is completely burnt in oxygen is : (Given : Molar mass in $g \ mol^{-1}$, $C : 12, H : 1, O : 16$)

$A$ $20 \ mL$ solution of $KMnO_4$ with a concentration of $1 \ N$ reacts with $20 \ mL$ of oxalic acid. The weight of oxalic acid in the $1 \ N$ solution is ......... $g$.