Read the passage given below and answer the following questions : When an aldehyde with no a-hydrogen reacts with concentrated aqueous NaOH, half the aldehyde is converted to carboxylic acid salt and other half is converted to an alcohol. In other words, half of the reactant is oxidized and other half is reduced. This reaction is known as Cannizzaro reaction The following questions are multiple choice questions. Choose the most appropriate answer: 1. A mixture of benzaldehyde and formaldehyde on heating with aqueous NaOH solution gives: 1. Benzyl alcohol and sodium formate. 2. Sodium benzoate and methyl alcohol. 3. Sodium benzoate and sodium formate. 4. Benzyl alcohol and methyl alcohol. 2. Which of the following compounds will undergo Cannizzaro reaction? 1. CH3CHO 2. CH3COCH3 3. C6H5CHO 4. C6H5CH2CHO 3. Trichloroacetaldehyde is subjected to Cannizzaro's reaction by using NaOH. The mixture of the products contains sodium trichloroacetate ion and another compound. The other compounds is: 1. 2, 2, 2-trichloroethanol 2. Trichloromethanol 3. 2, 2, 2-trichloropropanol 4. Chloroform 4. Which of the following reaction will not result in the formation of carbon-carbon bonds? 1. Cannizzaro reaction 2. Wurtz reaction 3. Reimer- Tiemann reaction 4. Friedel - Crafts acylation

1. (a) Benzyl alcohol and sodium formate. Explanation: It is an example of cross Cannizzaro reaction where aromatic aldehyde gets reduced to alcohol and aliphatic aldehyde gets oxidised to its sodium salt (both aldehydes must not contain any αα-hydrogen). 2. (c) C6H5CHO 3. (a) 2, 2, 2-trichloroethanol Explanation: The Cannizzaro product of given reaction yields 2, 2, 2-trichloroethanol. 4. (a) Cannizzaro reaction Explanation: C - C bond is not formed in Cannizzaro reaction while other reactions result in the formation of C - C bond.

Read the passage given below and answer the following questions :…

Read the passage given below and answer the following questions:

Glucose is known as dextrose because it occurs in nature as the optically active dextrorotatory isomer. lt is essential constituent of human blood. The blood normally contains 65 to 110mg of glucose per 100mL (hence named Blood sugar). The level may be much higher in diabetic persons. The urine of diabetic persons also contain considerable amount of glucose. ln combined form, it occurs in cane sugar and polysaccharides such as starch and cellulose.

Glucose has an aldehyde group (-CHO), one primary alcoholic group (-CH₂OH) and four secondary alcoholic groups (-CHOH) in their structure. Due to the presence five hydroxyl groups (-OH). glucose undergoes acetylation. Glucose also undergoes oxidation with mild oxidising agents like bromine water as well as with strong oxidising agents like nitric acid. Since glucose is readily oxidised, it acts as a strong reducing agent and reduces Tollen's reagent and Fehling solution. Glucose exists in two crystalline forms: $\alpha$-D-glucose and $\beta$-D-glucose. If either of the two forms is dissolved in water and allowed to stand, the specific rotation of the solution changes gradually, until a constant value is obtained. This change is called mutarotation.

A statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.

Assertion and reason both are correct statements and reason is correct explanation for assertion.
Assertion and reason both are correct statements but reason is not correct explanation for assertion.
Assertion is correct statement but reason is wrong statement.
Assertion is wrong statement but reason is correct statement.

Assertion: A diabetic person carries a packet of glucose with him always.

Reason: Glucose increases the blood sugar level almost instantaneously.

Assertion: On oxidation with nitric acid, glucose as well as gluconic acid both yield saccharic acid.

Reason: The pentaacetate of glucose does not react with hydroxylamine indicating the absence of free -CHO group.

Assertion: Glucose reacts with acetyl chloride to form pentaacetyl glucose.

Reason: The formation of pentaacetyl derivative confirms the presence of five -OH groups in glucose.

Assertion: A certain compound gives negative test with ninhydrin and positive test with Benedict's solution, the compound is an amino acid.

Reason: Glucose is a monosaccharide.

Assertion: The rapid interconversion of $\alpha$-D-glucose and $\beta$-D-glucose in solution is known as racemisation.

Reason: Hydrolysis reaction will take place when a mineral acid is treated with sugar.

→

Nemst equation relates the reduction potential of an electrochemical reaction to the standard potential and activities of the chemical species undergoing oxidation and reduction.

Let us consider the reaction, $\text{M}^{\text{n+}}_{(\text{aq})}\xrightarrow{\ \ \ \ \ \ \ \ }\text{nM}_\text{(s)}$

For this reaction, the electrode potential measured with respect to standard hydrogen electrode can be given as

$\text{E}_{\Big(\frac{\text{M}^{\text{n+}}}{\text{M}}\Big)}=\text{E}^\circ_{\Big(\frac{\text{M}^\text{n+}}{\text{M}}\Big)}-\frac{\text{RT}}{\text{nF}}\text{ln}\frac{[\text{M}]}{[\text{M}^{\text{n}+}]}$

In these questions (Q. No. i-iv), a statement of assertion followed by a statement ofreason is given. Choose the correct answer out of the following choices.

Assertion and reason both are correct statements and reason is correct explanation for assertion.
Assertion and reason both are correct statements but reason is not correct explanation for assertion.
Assertion is correct statement but reason is wrong statement.
Assertion is wrong statement but reason is correct statement.

Assertion: For concentration cell, $\text{Zn}_{(\text{s})}|\text{ Zn}^{2+}_{\text{(aq)}}||\text{ Zn}^{2+}_{(\text{aq})}|\text{ Zn}\\\ \ \ \ \ \ \ \ \ \ \ \ \text{C}_1\ \ \ \ \ \ \ \ \text{C}_2$

For spontaneous cell reaction, C₁ < C₂

Reason: For concentration cell, $\text{E}_\text{cell}=\frac{\text{RT}}{\text{nF}}\log\frac{\text{C}_2}{\text{C}_1}$

For spontaneous reaction, $\text{E}_\text{cell}=+\text{ve}\Rightarrow\text{C}_2>\text{C}_1$

Assertion: For the cell reaction, $\text{Zn}_{(\text{s})}+\text{Cu}^{2+}_{(\text{aq})}\xrightarrow{\ \ \ \ \ }\text{Zn}^{2+}_{(\text{aq})}+\text{Cu}_{(\text{s})}$ voltmeter gives zero reading at equilibrium.

Reason: At the equilibrium, there is no change in concentration of Cu2+ and Zn2+ ions.

Assertion: The Nernst equation gives the concentration dependence of emf of the cell.

Reason: In a cell, current flows from cathode to anode.

Assertion: Increase in the concentration of copper half cell in a cell, increases the emfofthe cell.

Reason: $\text{E}_\text{cell}=\text{E}^\circ_\text{cell}+\frac{0.059}{2}\log\frac{[\text{Cu}^{2+}]}{[\text{Zn}^{2+}]}$

Assertion: Electrode potential for the electrode $\frac{\text{Mn}^+}{\text{Mn}}$ with concentration is given by the expression under STP conditions.

$\text{E}=\text{E}^\circ+\frac{0.059}{\text{n}}\log[\text{Mn}^{+}]$

Reason: STP conditions require the temperature to be 273K.

→

Read the passage given below and answer the following questions:

Proteins are high molecular mass complex biomolecules of amino acids. The important proteins required for our body are enzymes, hormones, antibodies, transport proteins, structural proteins, contractile proteins etc. Except for glycine, all $\alpha$-amino acids have chiral carbon atom and most of them have L-configuration. The amino acids exists as dipolar ion called zwitter ion, in which a proton goes from the carboxyl group to the amino group. A large number of $\alpha$-amino acids are joined by peptide bonds forming polypeptides. The peptides having very large molecular mass (more than 10,000) are called proteins. The structure of proteins is described as primary structure giving sequence of linking of amino acids; secondary structure giving manner in which polypeptide chains are arranged and folded; tertiary structure giving folding, coiling or bonding polypeptide chains producing three dimensional structures and quaternary structure giving arrangement of sub-units in an aggregate protein molecule.

A statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.

Assertion and reason both are correct statements and reason is correct explanation for assertion.
Assertion and reason both are correct statements but reason is not correct explanation for assertion.
Assertion is correct statement but reason is wrong statement.
Assertion is wrong statement but reason is correct statement.

Assertion: Except glycine, all naturally occurring CL-amino acids are optically active.

Reason: All naturally occurring CL-amino acids, except glycine, has at least one asymmetric carbon.

Assertion: All amino acids are optically active.

Reason: Amino acids contain asymmetric carbon atoms.

Assertion: In $\alpha$-helix structure, intramolecular H-bonding takes place whereas in $\beta$-pleated structure, intermolecular H-bonding takes place.

Reason: An egg contains a soluble globular protein called albumin which is present in the white part.

Assertion: Secondary structure of protein refers to regular folding patterns of continuos portions of the polypeptide chain.

Reason: Out of 20 amino acids, only 12 amino acids can be synthesised by human body.

Assertion: The helical structure of protein is stabilised by intramolecular hydrogen bond between -NH and carbonyl oxygen.

Reason: Sanger's reagent is used for the identification of N-tenninal amino acid of peptide chain.

→

Electrical work done in unit time is equal to electrical potential multiplied by total charge passed. ln order to obtain maximum work from a cell, the charge has to be passed reversibly. The reversible work done by a cell is equal to decrease in its Gibb's energy. Hence, Gibb's energy of reaction is given by

$\Delta\text{G}=\text{nFE}_\text{cell}$

Hence, Eis the emfof the cell and nFis the amount of energy.

In these questions (Q. No. i-Iv), a statement of assertion followed by a statement ofreason is given. Choose the correct answer out of the following choices.

Assertion and reason both are correct statements and reason is correct explanation for assertion.
Assertion and reason both are correct statements but reason is not correct explanation for assertion.
Assertion is correct statement but reason is wrong statement.
Assertion is wrong statement but reason is correct statement.

Assertion: $\Delta\text{G}^\circ=-\text{nFE}^\circ$

Reason: E^º should be positive for a spontaneous reaction.

Assertion: An electrochemical cell can be set up only if the red ox reaction is spontaneous.

Reason: A reaction is spontaneous if free energy change is negative.

Assertion: For an electrochemical cell, $\Delta\text{G}<0$ and $\text{E}_\text{cell}>0.$

Reason: The given cell is non-spontaneous.

Assertion: Current stops flowing when E_cell = 0.

Reason: Equilibrium of the cell reaction is attained.

Assertion: E_cell should have a positive value for the cell to function.

Reason: E_cell = E_cathode - E_anode

→

Read the passage given below and answer the following questions:
At 298 K, the vapour pressure of pure benzene, C₆, H₆ is 0.256 bar and the vapour pressure of pure toluene C₆ H₅ CH₃ is 0.0925 bar. Two mixtures were prepared as follows:

7.8g of C₆ H₆ + 9.2g of toluene
3.9g of C₆ H₆ + 13.8g of toluene

The following questions are multiple choice questions. Choose the most appropriate answer:

The total vapour pressure (bar) of solution I is.

0.128
0.174
0.198
0.258

Which of the given solutions have higher vapour pressure?

I
II
Both have equal vapour pressure
Cannot be predicted

Mole fraction of benzene in vapour phase in solution I is.

0.128
0.174
0.734
0.266

Which of the following statements is/are correct?

Mole fraction of toluene in vapour phase is more in solution I.
Mole fraction of toluene in vapour phase is less in solution I.
Mole fraction of benzene in vapour phase is less in solution I.

Only II
Only I
I and III
II and III

Solution I is an example of a/an.

Ideal solution.
Non-ideal solution with positive deviation.
Non-ideal solution with negative deviation.
Can't be predicted.

→

Read the passage given below and answer the following questions:

Williamson's synthesis is used for the preparation of symmetrical as well as unsymmerical ether. It is S_N2 reaction mechanism. In Williamson's synthesis, 1º alkyl halide are used for preparation of ethers because 2º and 3º alkyl halide give alkene. Ethers are cleaved by hydrogen halides to alcohol and alkyl halide where alkyl halide is corresponding to that alkyl which has less number of carbon atom (it is because of less steric hindrance). In polar media unsymmetrical ether like tertiary butyl ethyl ether gives ethyl alcohol and tertiary butyl halide as reaction proceeds via carbocation.

In these questions (Q. No. i-iv), a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.

Assertion and reason both are correct statements and reason is correct explanation for assertion.
Assertion and reason both are correct statements but reason is not correct explanation for assertion.
Assertion is correct statement but reason is wrong statement.
Assertion is wrong statement but reason is correct statement.

Assertion: Rate of reaction of alkyl halide in Williamson's synthesis reaction is 1ºRX > 2ºRX > 3ºRX.

Reason: It is a type of bimolecular substitution reaction (S_N2).

Assertion: T-Butyl methyl ether is not prepared by the reaction of t-butyl bromide with sodium methoxide.

Reason: Sodium methoxide is a weak nucleophile.

Assertion: Williamson's synthesis method cannot be used for preparing diphenyl ether.

Reason: Aryl halides do not undergo nucleophilic substitution easily.

Assertion: When isopropyl bromide is treated with sodium isopropoxide, di-isopropyl ether is obtained as a major product.

Reason: With secondary alkyl halides, both substitution and elimination occur.

Assertion: Both symmetrical and unsymmetrical ethers can be prepared by Williamson's synthesis.

Reason: Williamson's synthesis is an example of nucleophilic substitution reaction.

→

Read the passage given below and answer the following questions:
The amines are basic in nature due to the presence of a lone pair of electron on N-atom of the -NH₂ group, which it can donate to electron deficient compounds. Aliphatic amines are stronger bases than NH₃ because of the +I effect of the alkyl groups. Greater the number of alkyl groups attached to N-atom, higher is the electron density on it and more will be the basicity. Thus, the order of basic nature of amines is expected to be 3º > 2º > 1º, however the observed order is 2º > 1º > 3º. This is explained on the basis of crowding on N-atom of the amine by alkyl groups which hinders the approach and bonding by a proton, consequently, the electron pair which is present on N is unavailable for donation and hence 3º amines are the weakest bases.
Aromatic amines are weaker bases than ammonia and aliphatic amines. Electron-donating groups such as -CH₃, -OCH₃, etc. increase the basicity while electron-withdrawing substitutes such as -NO₂, -CN, halogens, etc. decrease the basicity of amines. The effect of these substituents is more at p than at m-positions.
The following questions are multiple choice questions. Choose the most appropriate answer:

Which one of the following is the strongest base in aqueous solution?

Methyl amine.
Tri methyl amine.
Aniline.
Dimethyl amine.

Which order ofbasicity is correct?

Aniline > m-toluidine > o-toluidine
Aniline> o-toluidine > m-toluidine
o-toluidine > aniline> m-toluidine
o-toluidine < aniline < m-toluidine

What is the decreasing order of basicity of primary, secondary and tertiary ethylamines and NH₃?

NH₃ > C₂H₅NH₂ > (C₂H₅)₂NH > (C₂H₅)₃N
(C₂H₅)₃N > (C₂H₅)₂NH> C₂H₅NH₂ > NH₃
(C₂H₅)₂NH > C₂H₅NH₂> (C₂H₅)₃N > NH₃
(C₂H₅)₂NH > (C₂H₅)₃N > C₂H₅NH₂ > NH₃

The order of basic strength among the following amines in benzene solution is:

CH₃NH₂ > (CH₃)₃N > (CH₃)₂NH
(CH₃)₃N > (CH₃)₂NH > CH₃NH₂
CH₃NH₂ > (CH₃)₂NH > (CH₃)₃N
(CH₃)₃N > CH₃NH₂ > (CH₃)₂NH

Choose the correct statement.

Methylamine is slightly acidic.
Methylamine is less basic than ammonia.
Methylamine is a stronger base than ammonia.
Methylamine forms salts with alkalies.

→

Read the passage given below and answer the following questions:

Carbohydrates are polyhydroxy aldehydes and ketones and those compounds which on hydrolysis give such compounds are also carbohydrates. The carbohydrates which are not hydrolysed are called monosaccharides. Monosaccharides with aldehydic group are called aldose and those which free ketonic groups are called ketose. Carbohydrates are optically active. Number of optical isomers = 2ⁿ

Where n = numberofasymmetric carbons. Carbohydrates are mainlysynthesised by plants during photosynthesis. The monosaccharides give the characteristic reactions of alcohols and carbonyl group (aldehydes and ketones). It has been found that these monosaccharides exist in the form of cyclic structures. In cyctization, the -OH groups (generally C₅ or C₄ in aldohexoses and C₅ or C₆ in ketohexoses) combine with the aldehyde or keto group. As a result, cyclic structures of five or six membered rings containing one oxygen atom are formed, e.g., glucose forms a ring structure. Glucose contains one aldehyde group, one IO alcoholic group and four 2° alcoholic groups in its open chain structure.

The following questions are multiple choice questions. Choose the most appropriate answer:

First member of ketos sugar is:

Ketotriose.
Ketotetrose.
Ketopentose.
Ketohexose.

In CH₂OHCHOHCHOHCHOHCHOHCHO, the number of optical isomers will be:

16
8
32
4

Some statements are given below:

Glucose is aldohexose.
Naturally occurring glucose is dextrorotatory.
Glucose contains three chiral centres.
Glucose contains one 1° alcoholic group and four 2° alcoholic groups.

Among the above, correct statements are:

1 and 2 only
3 and 4 only
1, 2 and 4 only
1, 2, 3 and 4

Two hexoses fonn the same osazone, find the correct statement about these hexoses.

Both of them must be aldoses.
They are epimers at C-3.
The carbon atoms I and 2 in both have the same configuration.
The carbon atoms 3, 4 and 5 in both have the same configuration.

Which of the following reactions of glucose can be explained only by its cyclic structure?

Glucose forms cyanohydrin with HCN.
Glucose reacts with hydroxylamine to form an oxime.
Pentaacetate of glucose does not react with hydroxylamine.
Glucose is oxidised by nitric acid to gluconic acid.

→

Answer

Need a full question paper?

Explore more

Similar questions

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

Answer

Need a full question paper?

Explore more

Similar questions