Read the passage given below and answer the following questions: Iron forms many complexes in its +2 and +3 oxidation states such as [Fe(H_2O)_6]^ 2+ (A); [Fe(CN)_6]^ 4- (B); [Fe(H_2O)_6]^ 3+ (C); [Fe(CN)_6]^ 3- (D) , etc., They exhibit, different magnetic properties and undergo different hybridisation of iron. The following questions are multiple choice questions. Choose the most appropriate answer: 1. Which of the following statements is correct? 1. (B) is paramagnetic while (C) is diamagnetic. 2. Both (B) and (D) are outer orbital complexe. 3. Both (A) and (C) are paramagnetic. 4. (A) is outer orbital complex and (C) is inner orbital complex. 2. The complex having maximum magnetic moment is: 1. (A) 2. (B) 3. (C) 4. (D) 3. Which of the following does not represent correct configuration of the d- orbitals in the given complexes? 1. (A):t^4_ 2g e^2_g 2. (B):t^6_ 2g e^0_g 3. (C):t^4_ 2g e^1_g 4. (D):t^5_ 2g e^0_g 4. The spin only magnetic moment of complexes (A), (B), (C) and (D) are respectively (in BM). 1. 26,0,35,3 2. 0,26,35,3 3. 15,26,3,0 4. 3,8,0,15 5. Which of the given complexes are outer orbital complexes? 1. (A) and (B) only 2. (B) and (C) only 3. (A) and (C) only 4. (B) and (D) only

1. (c) Both (A) and (C) are paramagnetic. (A): sp^3d^2 hybridisation (outer orbital) No. of unpaired electrons = 4 (B): d^2sp^3 hybridisation (inner orbital) No. of unpaired electrons = 0 (C): sp^3d^2 hybridisation (outer orbital) No. of unpaired electrons = 5 (D): d^2sp^3 hybridisation (inner orbital) No. of unpaired electron = 1 2. (c) (C) It has 5 unpaired electrons. 3. (c) (C):t^4_ 2g e^1_g As H_2O is a weak ligand so, it should be t^4_ 2g e^1_g. 4. (a) 26,0,35,3 Magnetic moments of (A), (B), (C) and (D) are respectively. 4(4+2),0,5(5+2),1(1+2) 5. (c) (A) and (C) only

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

Dependence of the rate of reaction on the concentration of reactants, temperature, and other factors is the most general method for weeding out unsuitable reaction mechanisms. The term mechanism means all the individual collisional or elementary processes involving molecules $($atoms, radicals, and ions included$)$ that take place simultaneously or consecutively to produce the observed overall reaction. For example, when hydrogen gas reacts with bromine, the rate of the reaction was found to be proportional to the concentration of $H_2$ and to the square root of the concentration of $Br_2.$ Furthermore, the rate was inhibited by increasing the concentration of $HBr$ as the reaction proceeded. These observations are not consistent with a mechanism involving bimolecular collisions of a single molecule of each kind. The currently accepted mechanism is considerably more complicated, involving the dissociation of bromine molecules into atoms followed by reactions between atoms and molecules:
It is clear from this example that the mechanism cannot be predicted from the overall stoichiometry.
$($source: Moore, J. W., Pearson, $R. G. (1981).$ Kinetics and mechanism. John Wiley Sons.$)$
$(a).$ Predict the expression for the rate of reaction and order for the following:
$H_2 + Br_2 \rightarrow 2 HBr$
What are the units of rate constant for the above reaction?
$(b).$ How will the rate of reaction be affected if the concentration of $Br_2$ is tripled?

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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 $, C_1 < C_2$
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 $\ce{Cu2+}$ and $\ce{Zn2+}$ 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 $\text{STP}$ conditions.

$\text{E}=\text{E}^\circ+\frac{0.059}{\text{n}}\log[\text{Mn}^{+}]$
Reason : $\text{STP}$ conditions require the temperature to be $273K$.

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Read the passage given below and answer the following questions:
To explain bonding in coordination compounds various theories were proposed. One of the important theory was valence bond theory. According to that, the central metal ion in the complex makes available a number of empty orbitals for the formation of coordination bonds with suitable ligands. The appropriate atomic orbitals of the metal hybridise to give a set of equivalent orbitals of definite geometry.
The $d-$orbitals involved in the hybridisation may be either inner $d-$orbitals i.e.$, (n - 1)d$ or outer $d-$orbitals i.e.$, nd.$
For example, $Co^{3+}$ forms both inner orbital and outer orbital complexes, with ammonia it forms $[\ce{Co(NH3)6]^{3+}}$ and with fluorine it forms $[\ce{CoF6]^{3-}}$ complex ion.
The following questions are multiple choice questions. Choose the most appropriate answer :

Which of the following is not true for $[\ce{CoF6}]^{3-}$?

It is paramagnetic.
It has coordination number of $6.$
It is outer orbital complex.
It involves $d^2sp^3$ hybridisation.

$[\ce{Cr(H2O)6]Cl3}\ ($at. no. of $Cr = 24)$ has a magnetic moment of $3.83\ B.M.$ The correct distribution of $3d-$electrons in the central metal of the complex is :

$3\text{d}^1_\text{xy},3\text{d}^1_{\text{x}^2-\text{y}^2},3\text{d}^1_\text{yz}$
$3\text{d}^1_\text{xy},3\text{d}^1_{\text{yz}},3\text{d}^1_\text{zx}$
$3\text{d}^1_\text{xy},3\text{d}^1_{\text{zy}},3\text{d}^1_{\text{z}^2}$
$3\text{d}^1_{\text{x}^2-\text{y}^2},3\text{d}^1_{\text{z}^2},3\text{d}^1_\text{xz}$

Which of the following is true for $[\ce{Co(NH3)6}]^{3+}$?

It is an octahedral, di magnetic and outer orbital complex.
It is an octahedral, paramagnetic and outer orbital complex.
It is an octahedral, paramagnetic and inner orbital complex.
It is an octahedral, di magnetic and inner orbital complex.

The paramagnetism of $[\ce{CoF6}]^{3-}$ is due to.

$3$ electrons.
$4$ electrons.
$2$ electrons.
$1$ electron.

Which of the following is an inner orbital or low spin complex?

$[\ce{Ni(H2O)6}]^{3+}$
$[\ce{FeF6}]^{3-}$
$[\ce{Co(CN)6}]^{3-}$
$[\ce{NiCl4}]^{2-}$

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ln a reaction, the rates of disappearance of different reactants or rates of formation of different products may not be equal but rate of reaction at any instant of time has the same value expressed in terms of any reactant or product. Further, the rate of reaction may not depend upon the stoichiometric coefficients of the balanced chemical equation. The exact powers of molar concentrations of reactants on which rate depends are found experimentally and expressed in terms of 'order of reaction'. Each reaction has a characteristic rate constant depends upon temperature. The units of the rate constant depend upon the order of reaction.
The following questions are multiple choice questions. Choose the most appropriate answer:

The rate constant of a reaction is found to be $3 \times 10^{-3} \text{mol}^{-2} L^2 \sec^{-1}$. The order of the reaction is:

$0.5$
$2$
$3$
$1$

ln the reaction$, A + 3B \rightarrow 2C,$ the rate of formation of $C$ is:

The same as rate of consumption of $A$.
The same as the rate of consumption of $B$.
Twice the rate of consumption of $A$.
$\frac{3}{2}$ times the rate of consumption of $B$.

Rate of a reaction can be expressed by following rate expression, Rate $= k[A]^2 [B],$ if concentration of $A$ is increased by $3$ times and concentration of $B$ is increased by $2$ times, how many times rate of reaction increases?

$9$ times
$27$ times
$18$ times
$8$ times

The rate of a certain reaction is given by, rate $= k[H^+]^n.$ The rate increases $100$ times when the $pH$ changes from $3$ to $1$. The order $(n)$ of the reaction is:

$2$
$0$
$1$
$1.5$

ln a chemical reaction $A + 2B \rightarrow$ products, when concentration of $A$ is doubled, rate of the reaction increases $4$ times and when concentration of $B$ alone is doubled rate continues to be the same. The order of the reaction is:

$1$
$2$
$3$
$4$

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Read the passage given below and answer the following questions:
At $298 K,$ the vapour pressure of pure benzene $, C_6, H_6$ is $0.256$ bar and the vapour pressure of pure toluene $\ce{C_6 H_5 CH_3}$ is $0.0925$ bar. Two mixtures were prepared as follows:

$7.8g$ of $\ce{C_6 H_6 + 9.2g}$ of toluene
$3.9g$ of $\ce{C_6 H_6 + 13.8g}$ 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.

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Amines are basic in nature. The $pK_b$ value is a measure of the basic strength of an amine. Lower the value of $pK_b$ more basic is the amine. The effect of substituent on the basic strength of amines in aqueous solution was determined using titrations. The substituent $''X\ ''$ replaced $''-CH_2\ ''$ group in piperidine $($ compound $1)$ and propylamine $\ce{CH_3CH_2CH_2NH_2}, ($compound $2).$
Compound $1:$

Compound $2: \ce{HXCH_2CH_2NH_2}$

$($source: Hall $\text{Jr, H. K.} (1956).$ Field and inductive effects on the base strengths of amines. Journal of the American Chemical Society, $78(11), 2570-2572.)$
Study the above data and answer the following questions:
$a.$ Plot a graph between the electronegativity of the substituent vs $pK_b$ value of the corresponding substituted propyl amine $($given that $pK_a + pK_b =14).$ Is there any relation between the electronegativity of the substituent and its basic strength?
$b.$ The electronegativity of the substituent $''C_6H_5CON\ ''$ is $3.7,$ what is the expected $pKa$ value of compound $\ce{C_6H_5CONHCH_2CH_2NH_2}$?
$(i)\ 9.9\ (ii)\ 9.5\ (iii)\ 9.3\ (iv)\ 9.1$
$c.$ The pKa value of the substituted piperidine formed with substituent $''X\ ''$ is found to be $8.28.$ What is the expected electronegativity of $''X\ ''$
$(i)\ 3.5\ (ii)\ 3.4\ (iii)\ 3.8\ (iv)\ 3.1$

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Read the passage given below and answer the following questions:
The properties of the solutions which depend only on the number of solute particles but not on the nature of the solute are called colligative properties. Relative lowering in vapour pressure is also an example of colligative properties. For an experiment, sugar solution is prepared, for which lowering in vapour pressure was found to be 0.061 mm of Hg. (Vapour pressure of water at 20° C is 17.5 mm of Hg)
The following questions are multiple choice questions. Choose the most appropriate answer:

Relative lowering of vapour pressure for the given solution is.

0.00348
0.061
0.122
1.75

The vapour pressure (mm of Hg) of solution will be.

17.5
0.61
17.439
0.00348

Mole fraction of sugar in the solution is.

0.00348
0.9965
0.061
1.75

If weight of sugar taken is 5g in 108g of water, then molar mass of sugar will be.

358
120
240
400

The vapour pressure (mm of Hg) of water at 293K when 25g of glucose is dissolved in 450g of water is.

17.2
17.4
17.120
17.02

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Read the passage given below and answer the following questions :
Valence bond theory considers the bonding between the metal ion and the ligands as purely covalent. On the other hand, crystal field theory considers the metal$-$ligand bond to be ionic arising from electrostatic interaction between the metal ion and the ligands. In coordination compounds, the interaction between the ligand and the metal ion causes the five $d-$orbitals to split$-$up. This is called crystal field splitting and the energy difference between the two sets of energy level is called crystal field splitting energy. The crystal field splitting energy $(\Delta_0)$ depends upon the nature of the ligand. The actual configuration of complexes is divided by the relative values of $\Delta_0$ and $P\ ($pairing energy$)$.
If $\Delta_0<\text{P},$ then complex will be high spin.
If $\Delta_0>\text{P},$ then complex will be low spin
The following questions are multiple choice questions. Choose the most appropriate answer :

Which of the following ligand has lowest $\Delta_0$ value?

$CN^-$
$CO$
$F^-$
$NH_3$

The crystal field splitting energy for octahedral $(\Delta_0)$ and tetrahedral $(\Delta_t)$ complex is related as :

$\Delta_\text{t}=\frac{1}{2}\Delta_0$
$\Delta_\text{t}=\frac{4}{9}\Delta_0$
$\Delta_\text{t}=\frac{3}{5}\Delta_0$
$\Delta_\text{t}=\frac{2}{5}\Delta_0$

On the basis of crystal field theory, the electronic configuration of $d_4$ in two situations : $(i)\ t.0 > P$ and $(ii)\ t.0$

	$(i)$	$(ii)$
$(a)$	$\text{t}^4_{2\text{g}}\text{e}^0_\text{g}$	$\text{t}^3_{2\text{g}}\text{e}^1_\text{g}$
$(b)$	$\text{t}^3_{2\text{g}}\text{e}^1_\text{g}$	$\text{t}^4_{2\text{g}}\text{e}^0_\text{g}$
$(c)$	$\text{t}^3_{2\text{g}}\text{e}^1_\text{g}$	$\text{t}^3_{2\text{g}}\text{e}^1_\text{g}$
$(d)$	$\text{t}^4_{2\text{g}}\text{e}^0_\text{g}$	$\text{t}^4_{2\text{g}}\text{e}^0_\text{g}$

Using crystal field theory, calculate magnetic moment of central metal ion of $[FeF_6]^{4-}.$

$1.79B.M.$
$2.83B.M.$
$3.85B.M.$
$4.9B.M.$

Electronic configuration of $d-$orbitals in $[Ti(H_2O)_6]^{3+}$ ion in an octahedral crystal field is:

$\text{t}^1_{2\text{g}}\text{e}^0_\text{g}$
$\text{t}^2_{2\text{g}}\text{e}^0_\text{g}$
$\text{t}^0_{2\text{g}}\text{e}^1_\text{g}$
$\text{t}^1_{2\text{g}}\text{e}^1_\text{g}$

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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:
Carbohydrates can exist in either of two conformations, as determined by the orientation of the hydroxyl group about the asymmetric carbon farthest from the carbonyl.

By convention, a monosaccharide is said to have $D-$configuration if the hydroxyl group attached to the asymmetric carbon atom adjacent to the $-\ce{CH_2OH}$ group is on the right hand side irrespective of the positions of the other hydroxyl groups. On the other hand, the molecule is assigned $L-$configuration if the $-OH$ group attached to the carbon adjacent to the $- \ce{CH_2OH}$ group is on the left hand side.
The following questions are multiple choice questions. Choose the most appropriate answer:

$D-$Glyceraldehyde and $L-$Glyceraldehyde are:

Epimers.
Enantiomers.
Anomers.
Conformational diasteriomers.

Which of the following monosaccharides, is the majority found in the human body?

$D-$type.
$L-$type.
Both of these.
None of these.

The two functional groups present in a typical carbohydrate are:

$-\ce{OH}$ and $-\ce{COOH}$
$-\ce{CHO}$ and $-\ce{COOH}$
$ > \ce{C= O}$ and $-\ce{OH}$
$-\ce{OH}$ and $-\ce{CHO}$

Monosaccharides contain:

Always six carbon atoms.
Always five carbon atoms.
Always four carbon atoms.
May contain $3$ to $7$ carbon atoms.

The correct corresponding order of names of four aldoses with configuration given below respectively, is:

$L-$erythrose, $L-$threose, $L-$erythrose, $D-$threose.
$D-$threose, $D-$erythrose, $L-$threose, $L-$erythrose.
$L-$erythrose, $L-$threose, $D-$erythrose, $D-$threose.
$D-$erythrose, $D-$threose, $L-$erythrose, $L-$threose.

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