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. 1. Assertion and reason both are correct statements and reason is correct explanation for assertion. 2. Assertion and reason both are correct statements but reason is not correct explanation for assertion. 3. Assertion is correct statement but reason is wrong statement. 4. Assertion is wrong statement but reason is correct statement. 1. 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). 2. 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. 3. Assertion: Williamson's synthesis method cannot be used for preparing diphenyl ether. Reason: Aryl halides do not undergo nucleophilic substitution easily. 4. 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. 5. 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: …

Read the passage given below and answer the following questions:
The aryl halides are relatively less reactive towards nucleophilic substitution reactions as compared to alkyl halides. This low reactivity can be attributed to the following factors:

The $C - X$ bond in halobenzene has a partial double bond character due to involvement of halogen electrons in resonance with benzene ring.
The $C - X$ bond in aryl halides is less polar as compared to that in alkyl halides as $sp^2$ hyridised carbon is more electronegative than $sp^3$ hybridised carbon.

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: Primary benzylic halides are more reactive than primary alkyl halides towards $S_N1$ reactions.

Reason: Reactivity depends upon the nature of the nucleophile and the solvent.

Assertion: is more reactive than towards nucleophilic substitution reactions.

Reason: Tertiary alkyl halides react predominantly by $S_N1$ mechanism.

Assertion: Chlorobenzene is more reactive than p-chloroanisole to nucleophilic substitution reactions.

Reason: Greater the stability of carbanion, greater is its ease of formation and hence, more reactive is the aryl halide.

Assertion: $4-$Nitrochlorobenzene undergoes nucleophilic substitution more readily than chlorobenzene.

Reason: Chlorobenzene undergoes nucleophilic substitution by elimination-addition mechanism while 4-nitrochlorobenzene undergoes nucleophilic substitution by addition-elimination mechanism.

Assertion: Chlorobenzene is less reactive than benzene towards the electrophilic substitution reaction.

Reason: Resonance destabilises the carbocation.

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Read the passage given below and answer the following questions:
Metal carbonyl is an example of coordination compounds in which carbon monoxide (CO) acts as ligand. These are also called homoleptic carbonyls. These compounds contain both $\sigma$ and $\pi$ character. Some carbonyls have metal-metal bonds. The reactivity of metal carbonyls is due to (i) the metal centre and (ii) the CO ligands. CO is capable of accepting an appreciable amount of electron density from the metal atom into their empty $\pi$ or $\pi-\text{orbital}.$ These types of ligands are called $\pi-\text{accepter}$ or $\pi-\text{acid}$ ligands. These interactions increases the $\Delta_0$ value.
The following questions are multiple choice questions. Choose the most appropriate answer:

What is the oxidation state of metal in $[Mn_2(CO)_{10}]?$

$+1$
$-1$
$+2$
$0$

Among the following metal carbonyls, the $C-O$ bond order is lowest in:

$[Mn(CO)_6]^+$
$[Fe(CO)_5]$
$[Cr(CO)_6]$
$[V(CO)_6]^-$

Which of the following can be reduced easily?

$V(CO)_6$
$Mo(CO)_6$
$[Co(CO)_4]^-$
$Fe(CO)_5$

The oxidation state of cobalt in $K[Co(CO)_4]$ is:

$+1$
$+3$
$-1$
$0$

Structure of decacarbonyl manganese is:

Trigonal bipyramidial
Octahedral
Tetrahedral
Square pyramidal

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What is the most suitable pKa value of the substituted propylamine formed with substituent "X" with electronegativity 3.0
(i)10.67 (ii)10.08 (iii) 10.15 (iv)11.10

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Read the passage given below and answer the following questions:
Amines are basic in nature. The basic strength of amines can be expressed by their dissociation constant, $K_b$ or $pK_b$.
$\text{RNH}_2+\text{H}_2\text{O}\rightleftharpoons\text{RNH}^+_3+\text{OH}^-$
$\text{k}_\text{b}=\frac{[\text{RNH}^+_3][\text{OH}^-]}{[\text{RNH}_2]}\text{and}\text{ pk}_\text{b}=-\log\text{k}_\text{b}$
Greater the $K_b$ value or smaller the $pK_b$ value, more is the basic strength of a mine. Aryl amines such as aniline are less basic than aliphatic amines due to the involvement of lone pair of electrons on N-atom with the resonance in benzene. In derivatives of aniline, the electron releasing groups increase the basic strength while electron withdrawing groups decrease the basic strength. The base weakening effect of electron withdrawing group and base strengthening effect of electron releasing group is more marked at p-position than at m-position. a-Substituted aniline is less basic than aniline due to ortho effect and is probable due to combination of electronic and steric effect.
The following questions are multiple choice questions. Choose the most appropriate answer:

Which of the following has lowest $pK_b$ value?

The strongest base among the following is:

$C_6H_5NH_2$
$p-NO_2 - C_6H_4NH_2$
$m-NO_2 - C_6H_4NH_2$
$C_6H_5CH_2NH_2$

Maximum $pK_b$ value of:

$(CH_3CH_2)_2NH$
$(CH_3)_2NH$

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

Methylamine is more basic than $NH_3$.
Amines form hydrogen bonds.
Ethylamine has higher boiling point than propane.
Dimethylamine is less basic than methylamine.

$CH_3CH_2NH_2$ contains a basic $-NH_2$ group, but $CH_3CONH_2$ does not because:

Acetamide is amphoteric in character.
In ethylamine the electron pair on N-atom is delocalised by resonance.
In ethylamine there is no resonance while in acetamide the lone pair of electrons on N-atom is delocalised and is less available for protonation.
None of these.

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Read the passage given below and answer the following questions:
Amines are produced when an alcoholic solution of ammonia and an alkyl or a benzyl halide is heated in a sealed tube at 373K. This reaction is called ammonolysis and usually gives a mixture of primary, secondary and tertiary amines along with some quarternary ammonium salts. This reaction is an example of nucleophilic substitution reaction in which ammonia acts as a nucleophile due to the presence of a lone pair of electrons on the nitrogen atom. However this method cannot be used for the preparation of aryl amines. One of the most convenient methods for the preparation of aryl amines is reduction of nitro compounds. Aryl amines can also be prepared by reduction of nitrites or Gabriel phthalimide synthesis.
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: Ammonolysis of alkyl halides only produces 2° amines.

Reason: Ammonolysis of alkyl halides involves the reaction between alkyl halides and alcoholic ammonia.

Assertion: Gabriel-phthalimide reaction can be used to prepare both aryl and alkyl primary amines.

Reason: Aryl halides are more reactive alkyl halides towards nucleophilic substitution reactions.

Assertion: Anunonolysis method cannot be used for the preparation of aryl amines.

Reason: Aryl halides are much less reactive than alkyl halides towards nucleophilic substitution reaction.

Assertion: Ammonolysis can be used to prepare pure primary amines.

Reason: Ammonolysis of haloalkanes lead to multiple ammonium salts.

Assertion: Aromatic 1º amines can not be prepared by Gabriel phthalimide synthesis.

Reason: Aryl halides do not undergo nucleophilic substitution with anion formed by phthalimide.

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Read the passage given below and answer the following questions:
When haloalkanes with $\beta-$hydrogen atom are boiled with alcoholic solution of KOH, they undergo elimination of hydrogen halide resulting in the formation of alkenes. These reactions are called $\beta-$elimination reactions or dehydrohalogenation reactions. These reactions follow Saytzeff's rule. Substitution and elimination reactions often compete with each other. Mostly bases behave as nucleophiles and therefore can engage in substitution or elimination reactions depending upon the alkyl halide and the reaction conditions.
The following questions are multiple choice questions. Choose the most appropriate answer:

Among the following the most reactive towards alcoholic $KOH$ is:

$CH_2 = CHBr$
$CH_3COCH_2CH_2Br$
$CH_3CH2Br$
$CH_3CH_2CH_2Br$

The general reaction, $\text{R}-\text{X}\xrightarrow{\text{aq.OH}^-}\text{ROH}+\text{X}^-,$ is expected to follow decreasing order of reactivity as in:

$t-BuI> t-BuBr > t-BuCI > t-BuF$
$t-BuF > t-BuCI > t-BuBr > t-BuI$
$t-BuBr > t-BuCI >t-BuI> t-BuF$
$t-BuF > t-BuCI > t-BuI > t-BuBr$

Reaction of t-butyl bromide with sodium methoxide produces:

Sodium t-butoxide.
t-butyl methyl ether.
Iso-butane.
Iso-butylene.

In the elimination reactions, the reactivity of alkyl halides follows the sequence:

$R - F > R - CI > R - Br > R - I$
$R - I > R - Br > R - Cl > R - F$
$R - I > R - F > R - Br > R - CI$
$R - F > R - I > R - Br > R - CI$

The ease of dehydrohalogenation of alkyl halide with alcoholic $KOH$ is:

$3^\circ < 2^\circ < 1^\circ$
$3^\circ > 2^\circ > 1^\circ$
$3^\circ < 2^\circ > 1^\circ$
$3^\circ > 2^\circ < 1^\circ$

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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 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: $E_{cell} = E_{cathode} - E_{anode}$

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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 $= 2^n$
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 $C_5$ or $C_4$ in aldohexoses and $C_5$ or $C_6$ 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 $2^\circ$ 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 $CH_2OHCHOHCHOHCHOHCHOHCHO$, 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 $1^\circ$ alcoholic group and four $2^\circ$ 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.

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Read the passage given below and answer the following questions:
The addition reaction of enol or enolate to the carbonyl functional group of aldehyde or ketone is known as aldol addition. The β-hydroxyaldehyde or ββ-hydroxyketone so obtained undergo dehydration in second step to produce a conjugated enone. The first part of reaction is an addition reaction and the second part is an elimination reaction. Carbonyl compound having αα-hydrogen undergoes aldol condensation reaction.

Condensation reaction is the reverse of which of the following reaction?

Lock and key hypothesis
Oxidation
Hydrolysis
Glycogen formation

Which of the following compounds would be the main product of an aldol condensation of acetaldehyde and acetone?

$CH_3CH=CHCHO$
$CH_3CH=CHCOCH_3$
$(CH_3)_2C=CHCHO$
$(CH_3)_2C=CHCOCH_3$

Which combination of carbonyl compounds gives phenyl vinyl ketone by an aldol condensation?

Acetophenone and Formaldehyde
Acetophenone and acetaldehyde
Benzaldehyde and acetaldehyde
Benzaldehyde and acetone
Which of the following will undergo aldol condensation?

$HCHO$
$CH_3CH_2OH$
$C_6H_5CHO$
$CH_3CH_2CHO$

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Read the passage given below and answer the following questions:
The adjective 'crystalline' when applied to solids, implies an ideal crystal in which the structural units, termed as unit cells, are repeated regularly and indefinitely in three dimensions in space. The unit cell, containing at least one molecule, has a definite orientation and shape defined by the translational vectors, a, b and c. The unit cell therefore has a definite volume, V that contains the atoms and molecules necessary for generating the crystal. Every crystal can be classified as a member of one of the seven possible crystal systems or crystal classes that are defined by the relationships between the individual dimensions, a, b and c of the unit cell and between the individual angles, ⁣$\alpha,\beta$ and $\gamma$ of the unit cell. The structure of the given crystal may be assigned to one of the $7$ crystal systems, to one of the $14$ Bravais lattices, and to one of the 230 space groups. These uniquely define the possible ways of arranging atoms in a three-dimensional solid. Based on these observations, seven crystal systems were identified: triclinic, monoclinic, trigonal or rhombohedral, tetragonal, hexagonal, rhombic or orthorhombic and cubic.
The following questions are multiple choice questions. Choose the most appropriate answer:

The crystal system of a compound with unit cell dimensions, $a = 0.38$7nm, $b = 0.387$nm and $c = 0.504$nm $\alpha=\beta=90^\circ$ and $\gamma=120^\circ$ is.

Cubic
Hexagonal
Orthorhombic
Rhombohedral.

The unit cell with the structure given below represents________________crystal system.

Cubic
Orthorhombic
tetragonal
trigonal

In a triclinic crystal.

$\text{a}=\text{b}=\text{c},\ \alpha=\beta=\gamma\neq90^\circ$
$\text{a}\neq\text{b}=\text{c},\ \alpha=\beta=\gamma=90^\circ$
$\text{a}\neq\text{b}\neq\text{c},\ \alpha\neq\beta\neq\gamma\neq90^\circ$
$\text{a}\neq\text{b}\neq\text{c},\ \alpha=\gamma=90^\circ\beta\neq90^\circ$

The unit cell with dimensions $\alpha=\beta=\gamma=90^\circ,\ \text{a}=\text{b}\neq\text{c}$ is.

Cubic
Triclinic
Hexagonal
Tetragonal.

An example of orthorhombic crystal system is.

$SnO_2$
$KN0_3$
$ZnO$
$K_2Cr_2O_7$

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