What is the value of percent atom economy when reactants having a sum of formula weight $78 \ u$ result in the formation of a product with a formula weight of $65 \ u$ (in $\%$)?

At $T \ K$,$100 \ L$ of dry oxygen is present in a sealed container. It is subjected to silent electric discharge,until the volumes of oxygen and ozone become equal. What is the volume (in litres) of ozone formed at $T \ K$?

The conversion of oxygen to ozone occurs to the extent of $15\%$ only. The mass of ozone that can be prepared from $67.2 \ L$ of oxygen at $1 \ atm$ and $273 \ K$ will be ............ $g$.

What is the amount of water formed by combustion of $1.6 \ g$ methane (in $g$)?

When oxygen is heated in the presence of a catalyst,$15 \%$ of it is converted into ozone. How many grams of oxygen are required to produce $33.6 \, L$ of $O_3$ at $STP$?

$A$ cylinder of cooking gas in a household contains $11.6 \, kg$ of butane. The thermochemical reaction for the combustion of butane is,
$2 C_4H_{10(g)} + 13 O_{2(g)} \longrightarrow 8 CO_{2(g)} + 10 H_2O_{(l)}$
$\Delta H = -2658 \, kJ/mol$
If the household needs $15000 \, kJ$ of energy per day,the cooking gas cylinder will last for about $...... \, days$.