Partial pressure of ethanol $=4.556 \,kPa$
Total pressure $=$ Partial pressure of methanol $+$ Partial pressure of ethanol
Total pressure $=2.619+4.556=7.175\, kPa$
$X _{\text {methanol: }}$ : Mole fraction of methanol
$X _{\text {ethanol: }}$ : Mole fraction of ethanol
The partial pressure of methanol $= X _{\text {methanol }} \times$ Total pressure
$\therefore X _{\text {methanol }}=\frac{2.619}{7.175}$
$=0.365$
$\therefore$ Mole fraction of ethanol $= 1 -$ Mole fraction of methanol
$=1-0.365$
$=0.635$
Hence, the correct option is $B$.
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$Zn\left( s \right) + C{u^{2 + }}\left( {aq} \right) \rightleftharpoons Z{n^{2 + }}\left( {aq} \right) + Cu\left( s \right)$
Standard reaction enthalpy $\left( {{\Delta _r}{H^ - }} \right)$ ....... $\mathrm{kJ}$
Assertion $A$ :$[6]$ Annulene.$[8]$ Annulene and cis - $[10]$ Annulene, are respectively aromatic, not-aromatic and aromatic.
Reason $R$ : Planarity is one of the requirements of aromatic systems.
In the light of the above statements, choose the most appropriate answer from the options given below.