Download App

Aldehydes, Ketones, and Carboxylic Acids — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryAldehydes, Ketones, and Carboxylic Acids3 Marks
Question
Mention a chemical property in which methanoic acid differs from acetic acid.
✓

Answer

Methanoic acid acts as a reducing agent and hence decolourises the pink colour of acidified $KMnO_4$ solution but acetic acid does not.
$5\text{HCOOH}+2\text{KMnO}_4+3\text{H}_2\text{SO}_4 \rightarrow 5\text{CO}_2+\text{K}_2\text{SO}_4+2\text{MnSO}_4+8\text{H}_2\text{O}\\ ^\text{Methanoic acid}\ \ \ \ \ \ ^\text{(Pink)}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ ^\text{(Colourless)}$
$\text{CH}_3\text{COOH}\ \xrightarrow{\text{KMnO}_4/\text{H}_2\text{SO}_4}$ No change in pink colour of $KMNO_4$ solution.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from Aldehydes, Ketones, and Carboxylic Acids→Aldehydes, Ketones, and Carboxylic Acids — all question types→Chemistry STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Calculate the following:
  1. Number of $NaCl$ units in a unit cell of $NaCl.$
  2. Number of $CsCl$ unit in a unit cell of $CsCl.$
→
A special thermometer (Beckmann thermometer) is used to determine molecular weight by freezing point depression method instead of ordinary thermometer. Why?
→
Give reasons:
a. $E ^{\circ}$ value for $Mn ^{3+} / Mn ^{2+}$ couple is much more positive than that for $Fe ^{3+} / Fe ^{2+}$.
b. Iron has higher enthalpy of atomization than that of copper.
c. $Sc ^{3+}$ is colourless in aqueous solution whereas $Ti ^{3+}$ is coloured.
→
The equilibrium constant of cell reaction :
$Sn^{4+}(.aq) + Al(s) Al^{3+ }\rightarrow + Sn^{2+} (aq)$ is $4.617 x 10^{184},$ at $25 ^\circ C$
$a.$ Calculate the standard emf of the cell. $($Given: $\log 4.617 x 10^{184} = 184.6644)$
$b.$ What will be the $E^\circ $ of the half cell $Al^{3+}/Al,$ if $E^\circ $ of half cell $Sn^{4+}/Sn^{2+} $ is $4+ 0.15 V.$
→
Explain the importance of carbohydrate compounds.
→
An organic compound ' $A$ ' $\left(\mathrm{C}_3 \mathrm{H}_4\right)$ on hydration in presence of $\mathrm{H}_2 \mathrm{SO}_4 / \mathrm{HgSO}_4$ gives compound '$B$' $\left(\mathrm{C}_3 \mathrm{H}_6 \mathrm{O}\right)$. Compound 'B' gives white crystalline product ( D ) with sodium hydrogensulphite. It gives negative Tollens' test and positive iodoform's test. On drastic oxidation 'B' gives compound ' $\mathrm{C}^{\prime}\left(\mathrm{C}_2 \mathrm{H}_4 \mathrm{O}_2\right)$ along with formic acid. Identify compounds ' A ', ' B ' and ' C ' and explain all the reactions.
→
Write the chemical equation for the following conversion (not more than 2 steps):
Acetaldehyde to butane-1,3-diol.
→
Sodium metal crystallises in bcc lattice with the cell edge, $4.29\mathring{\text{A}}.$ What is the radius of sodium metal? What is the length of the body diagonal of the unit cell?
→
In a reaction between A and B, the initial rate of reaction $(r_0)$ was measured for different initial concentrations of A and B as given below:
$A/mol L^{-1}$ $0.20$ $0.20$ $0.40$
$B/mol L^{-1}$ $0.30$ $0.10$ $0.05$
$r_0/mol L^{-1} s^{-1}$ $5.07 \times 10^{-5}$ $5.07 \times 10^{-5}$ $1.43 \times 10^{-4}$
What is the order of the reaction with respect to $A$ and $B$?
→
Explain the following cases giving appropriate reasons:
  1. Nickel does not form low spin octahedral complexes.
  2. The $\pi$-complexes are known for the transition metals only.
  3. $Co^{2+}$ is easily oxidised to $Co^{3+}$ in the presence of a strong ligand.
→