8.1. Aldehydes and ketones — Chemistry STD 12 Science — Question

Assertion $A$: $\mathrm{pK}_{\mathrm{a}}$ value of phenol is $10.0$ while that of ethanol is $15.9$.

Reason $R$: Ethanol is stronger acid than phenol.In the light of the above statements, choose the correct answer from the options given below:

(Assume : Densities of the solutions $A$ and $B$ are the same as that of water and the soluble salts dissociate completely.)

Use: Molal elevation constant (Ebullioscopic Constant), $K _{ b }=0.5 K kg mol ^{-1}$; Boiling point of pure water as $100^{\circ} C$.)

($1$) The value of $x$ is

($2$) The value of $|y|$ is

${X_{\left( s \right)}} + Y_{\left( {aq} \right)}^{ + 2} \rightleftharpoons {Y_{\left( s \right)}} + X_{\left( {aq} \right)}^{2 + }$

Given : 

$E_{{x^{ + 2}}/x}^o =  - 1.36\,volt$ ;   

$E_{{y^{ + 2}}/y}^o =  - 0.76\,volt\,\frac{{2.303\,RT}}{F} = 0.06$

Assertion $A:$ $3.1500\,g$ of hydrated oxalic acid dissolved in water to make $250.0\,mL$ solution will result in $0.1\,M$ oxalic acid solution.

Reason $R:$ Molar mass of hydrated oxalic acid is $126\,g\,mol ^{-1}$.

In the light of the above statements, chose the correct answer from the options given below:

$[i.e.\, \Lambda ^o_{m(NH_4OH)}]$ is equal to