Heating oxygen in the presence of a catalyst results in $15\%$ conversion to ozone. How many grams of oxygen are required to produce $33.6 \ L$ of $O_3$ at $STP$?

When the same amount of zinc is treated separately with an excess of sulphuric acid and an excess of sodium hydroxide solution,the ratio of the volumes of hydrogen evolved is:

$17.0 \ g$ of $NH_3$ completely vaporizes at $-33.42^{\circ}C$ and $1 \ bar$ pressure,and the enthalpy change in the process is $23.4 \ kJ \ mol^{-1}$. The enthalpy change for the vaporization of $85 \ g$ of $NH_3$ under the same conditions is $..... \ kJ$.

Methylation of $10 \ g$ of benzene gave $9.2 \ g$ of toluene. Calculate the percentage yield of toluene $......$. (Nearest integer)

At $STP$,'$x$' $g$ of a metal hydrogen carbonate $(MHCO_3)$ (molar mass $84 \ g \ mol^{-1}$) on heating gives $CO_2$,which can completely react with $0.2 \ mol$ of $MOH$ (molar mass $40 \ g \ mol^{-1}$) to give $MHCO_3$. The value of '$x$' is

How many grams of calcium chloride are required to produce $14.35 \ g$ of $AgCl$? (Atomic weights: $Ca = 40, Ag = 108, Cl = 35.5$)