For the combustion reaction of $1 \, mol$ of hydrocarbon $C_xH_{2y}$,the number of moles of $O_2$ required will be............

The yield of each step as actually carried out in the laboratory is given in the reaction scheme below. Calculate the overall percentage yield of the reaction.
$Me_3C-CO-CH_3$ $\xrightarrow{58\% (A)} Me_3C-CO-CH_2Br$ $\xrightarrow{54\% (B)} Me_3C-CH(OH)-CH_2Br$ $\xrightarrow{68\% (C)} Me_3C-CH(O)CH_2$

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 $KClO_3 = 122.5 \, g \, mol^{-1}$)

$10 \ mL$ of a gaseous hydrocarbon on combustion gives $40 \ mL$ of $CO_{2(g)}$ and $50 \ mL$ of $H_2O_{(g)}$. The hydrocarbon is $-$

$1.44 \ g$ of titanium (At. wt. $= 48$) reacted with excess of $O_2$ to produce $x \ g$ of a non-stoichiometric compound $Ti_{1.44}O$. The value of $x$ is:

$x$ grams of calcium carbonate was completely burnt in air. The weight of the solid residue formed is $28 \,g$. What is the value of $x$ (in grams)?