Aldehyde ketones & carboxylic Acid MCQs for NEET — Chemistry Questions with Answers

 ${\mathrm{CH}}_4\stackrel{\left[\mathrm{O}\right]}{\to }{\mathrm{H}}_2\mathrm{O} + \mathrm{CO}$

(b) If BaSO₄ is not used, the reaction will give alcohol. BaSO₄ retards the activity of Pd.

             RCOCl $\underset{\mathrm{Pd}/{\mathrm{BaSO}}_4}{\overset{{\mathrm{H}}_2}{\to }}$ RCHO

             RCOCl$\underset{\mathrm{Pd}}{\overset{{\mathrm{H}}_2}{\to }}$RCHO$\to$RCH₂OH

The partial hydrolysis of one mole of peroxodisulfuric acid (H₂S₂O₈) produces one mole of sulfuric acid (H₂SO₄) and one mole of peroxomonosulfuric acid (H₂SO₅). The reaction is: H₂S₂O₈ + H₂O → H₂SO₄ + H₂SO₅.

(a) H₃BO₃ acts as weak monobasic Lewis acid.

(i) B(OH)₃ + NaOH  $\to$Na[B(OH)₄] 

on addition of cis 1,2 diol in H3bo3 solution, acidic strength of H₃BO₃ increases due to chelation effect.

$$\begin{gathered} \left(2\right) {\mathrm{PCl}}_3+3{\mathrm{H}}_2\mathrm{O}\to {\mathrm{H}}_3{\mathrm{PO}}_3+3\mathrm{HCl} \\ {\mathrm{H}}_3{\mathrm{PO}}_3 \mathrm{is} \mathrm{a} \mathrm{diabasic} \mathrm{acid}. \end{gathered}$$

Acidity is directly proportional to free oxygen and inversely proportional to -OH group.

The double bonded oxygen has negative inductive effect (-I). And this electron withdrawing effect is experienced by one H$\mathrm{H}$ of the one −OH$-\mathrm{O}\mathrm{H}$ group in H3PO2. Hence it has greatest acidic strength.

Similarly, the -I effect of O is experienced by two H of the two −OH groups in H3PO3, hence electron withdrawing effect is reduced because it is getting distributed between two groups. Hence, it has lesser acidic strength. Similarly, in H3PO4, it is distributed between 3 groups and so the acidic strength is least.

(b) SO₂ gas is obtained when any sulphide ore is roasted.

2M₂S + 3O₂ $\to$2M₂O + 2SO₂

This gas exhibits all the characteristics given in the question.

When Cl₂ gas reacts with hot and concentrated NaOH solution, chlorine undergoes disproportionation. Its oxidation states change from 0 to -1 (in NaOCl) and 0 to +5 (in NaClO₃). This disproportionation reaction is used in the manufacturing of bleaching powder.

(b) ${\mathrm{HIO}}_4>{\mathrm{HBrO}}_4>{\mathrm{HCIO}}_4$$\Rightarrow$ acidic strength has been decided on the basis of 

      electronnegativity or charge density on central atom.

(C)Conjugate base of $HN{O}_3$, the $N{O}_3^{-}$ is more stable (charge dispersion on three oxygen atoms) than conjugate base of $HN{O}_2$, the $N{O}_2^{-}$ (charge dispersion on two oxygen atoms).

There are three nitrogen to oxygen bonds in $HN{O}_3$ and two in $HN{O}_2.$