The unique behavior of Cu, having a positive Eo accounts for its inability to liberate H2 from acids. Only oxidizing acids (nitric and hot concentrated sulphuric acid) react with Cu, the acids being reduced. The stability of the half-filled (d⁵) subshell in Mn²⁺ and the completely filled (d¹⁰ ) configuration in Zn²⁺ are related to their E^o (M³⁺ /M²⁺) values. The low value for Sc reflects the stability of Sc³⁺ which has a noble gas configuration. The comparatively high value for Mn shows that Mn²⁺(d⁵) is particularly stable, whereas a comparatively low value for Fe shows the extra stability of Fe³⁺ (d⁵). The comparatively low value for V is related to the stability of V²⁺ (half-filled t_2g level).
1. Standard reduction electrode potential of Zn²⁺ /Zn is – 0.76 V. This means
(a) ZnO cannot be reduced to Zn by H₂ under standard conditions
(b) Zn cannot liberate H₂ with concentrated acids
(c) Zn is generally the anode in an electrochemical cell
(d) Zn is generally the cathode in an electrochemical cell.
2. E^o values for the couples Cr³⁺/Cr²⁺ and Mn³⁺ /Mn²⁺ are -0.41 and +1.51 volts respectively. These values suggest that
(a) ZnO cannot be reduced to Zn by H2 under standard conditions
(b) Cr²⁺ is more stable than Cr³⁺ state
(c) Mn³⁺ is more stable than Mn²⁺
(d) Cr²⁺ acts as an oxidizing agent whereas Mn³⁺ acts as a reducing agent
3.The reduction potential values of M, Nand O are +2.46, -1.13 and -3.13 Y respectively. Which of the following order is correct regarding their reducing property?
(a) O>N>M
(b) O>M>N
(c) M>N>O
(d) M>O>N
4. Which of the following statements are true?
(a) Mn²⁺ compounds are more stable than Fe²⁺ towards oxidation to +3 state.
(b) Titanium and copper both in the first series of transition metals exhibits +1 oxidation state most frequently.
(c) Cu⁺ ion is stable in aqueous solutions.
(d) The E⁰ value for the Mn³⁺ /Mn²⁺ couple is much more positive than that for Cr³⁺/Cr²⁺ or Fe³⁺/Fe²⁺.
(a) (b) and (c)
(b) (a) and (d)
(c) (a) and (c)
(d) (b) and (d)

The half-life of a reaction is the time required for the concentration of reactant to decrease by half,

this means t_1/2 is independent of initial concentration. The figure shows a typical variation of concentration of reactant exhibiting first-order kinetics. It may be noted that though the major portion of the first-order kinetics may be over in a finite time, the reaction will never cease as the concentration of reactant will be zero only at infinite time.

1.A first-order reaction has a rate constant k = 3.01 × 10^–3 /s. How long it will take to decompose half of the reactant?
(a) 2.303 s
(b) 23.03 s
(c) 230.3 s
(d) 2303 s
2.The rate constant for a first-order reaction is 7.0 × 10–4 s–1. If the initial concentration of reactant is 0.080 M, what is the half-life of the reaction?
(a) 990 s
(b) 79.2 s
(c) 12375 s
(d) 10.10 × 10^–4 s
3.For the half-life period of a first-order reaction, which one of the following statements is generally false?
(a) It is independent of initial concentration.
(b) It is dependent on the rate of the reaction.
(c) At t1/2, the concentration of the reactant is reduced by half.
(d) None of these
4.The rate of a first-order reaction is 0.04 mol L^–1 s^–1 at 10 minutes and 0.03 mol L^–1 s^–1 at 20 minutes after initiation. The half-life of the reaction is
(a) 4.408 min
(b) 44.086 min
(c) 24.086 min
(d) 2.408 min
5.The plot of t_1/2 vs initial concentration [A]₀ for a first-order reaction is given by

The concentration of a solute is very important in studying chemical reactions because it determines how often molecules collide in solution and thus indirectly determines the rate of reactions and the conditions at equilibrium. There are several ways to express the amount of solute present in a solution. The concentration of a solution is a measure of the amount of solute that has been dissolved in a given amount of solvent or solution. Concentration can be expressed in terms of molarity, molality, parts per million, mass percentage, volume percentage, etc.
(i) The molarity (in mol L^-1) of the given solution will be
(a) 1.56
(b) 1.89
(c) 0.263
(d) 1.44
(ii) Which of the following is temperature dependent?
(a) Molarity
(b) Molality
(c) Mole fraction
(d) Mass percentage
(iii) Which of the following is true for an aqueous solution of the solute in terms of concentration?
(a) 1 M = 1 m
(b) 1M > 1m
(c) 1M < 1 m
(d) Cannot be predicted

Read the passage given below and answer the following questions:
Pentose and hexose undergo intramolecular hemiacetal or hemiketal formation due to combination of the -OH group with the carbonyl group. The actual structure is either of five or six membered ring containing an oxygen atom. In the free state all pentoses and hexoses exist in pyranose form (resembling pyran). However, in the combined state some of them exist as five membered cyclic structures, called furanose (resembling furan).

The cyclic structure of glucose is represented by Haworth structure:

\(\alpha \) and \(\beta\) -D-glucose have different configuration at anomeric (C-l) carbon atom, hence are called anomers and the C-l carbon atom is called anomeric carbon (glycosidic carbon).
The six membered cyclic structure of glucose is called pyranose structure.
The following questions are multiple choice questions. Choose the most appropriate answer:
(i) \(\alpha\) -D(+)-glucose and \(\beta\) -D( +)glucose are

(a) enantiomers

(b) conformers

(c) epimers

(d) anomers

(ii) The following carbohydrate is

(a) a ketohexose	(b) an aldohexose
(c) an \(\alpha \)-furanose	(d) an \(\alpha \)-pyranose

(iii) In the following structure,

anomeric carbon is

(a) C-l

(b) C-2

(c) C-3

(d) C-4

(iv) The term anomers of glucose refers to

(a) isomers of glucose that differ in configurations at carbons one and four (C-l and C-4)

(b) a mixture of (D)-glucose and (L)-glucose

(c) enantiomers of glucose

(d) isomers of glucose that differ in configuration at carbon one (C-l).

Read the passage given below and answer the following questions:
When the mixture contains the three amine salts (1°, 2° and 3°) along with quaternary salt, it is distilled with KOH solution. The three amines distill, leaving the quaternary salt unchanged in the solution. Then the mixture of amines is separated by fractional distillation, Hinsbergs method and Hoffmann's method.

The following questions are multiple choice questions. Choose the most appropriate answer:
(i) Hinsberg reagent is

(a) aliphatic sulphonyl chloride	(b) phthalamide
(c) aromatic sulphonyl chloride	(d) anhydrous ZnCl2 + conc. HCl.

(ii) Primary amine with Hinsberg's reagent forms

(a) N-alkyl benzene sulphonamide soluble in KOH solution

(b) N-alkyl benzene sulphonamide insoluble in KOH solution

(c) N, N-dialkyl benzene sulphonamide soluble in KOH solution

(d) N, N-dialkyl benzene sulphonamide insoluble in KOH solution.

(iii) To separate amines in a mixture Hoffmann's method is used. The Hoffmann's reagent is

(a) benzenesulphonyl chloride	(b) diethyloxalate
(c) benzeneisocyanide	(d) p-toulenesulphonic acid.

(iv) 3^o amines with Hinsberg's reagent give

(a) no reaction	(b) product which is same as that of 10 amine
(c) product which is same as that of 2° amine	(d) products which is a quaternary salt.

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 :
(i) A mixture of benzaldehyde and formaldehyde on heating with aqueous NaOH solution gives

(a) benzyl alcohol and sodium formate	(b) sodium benzoate and methyl alcohol
(c) sodium benzoate and sodium formate	(d) benzyl alcohol and methyl alcohol.

(ii) Which of the following compounds will undergo Cannizzaro reaction?

(a) CH3CHO	(b) CH3COCH3
(c) C6H5CHO	(d) C6H5CH2CHO

(iii) 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

(a) 2, 2, 2-trichloroethanol	(b) trichloromethanol
(c) 2, 2, 2-trichloropropanol	(d) chloroform

(iv) Which of the following reaction will not result in the formation of carbon-carbon bonds?

(a) Cannizzaro reaction	(b) Wurtz reaction
(c) Reimer- Tiemann reaction	(d) Friedel-Crafts acylation

Read the passage given below and answer the following questions:
Haloarenes are less reactive than haloalkanes. The low reactivity of haloarenes can be attributed to
(i) resonance effect
(ii) Sp² hybridisation of C - X bond
(iii) polarity of C - X bond
(iv) instability of phenyl cation (formed by self-ionisation ofhaloarene)
(v) repulsion between the electron rich attacking nucleophiles and electron rich arenes.
Reactivity of haloarenes can be increased or decreased by the presence of certain groups at certain positions for example, nitro (-NO₂) group at olp positions increases the reactivity of haloarenes towards nucleophilc substitution reactions.
The following questions are multiple choice questions. Choose the most appropriate answer:
(i) Aryl halides are less reactive towards nucleophilic substitution reaction as compared to alkyl halides due to

(a) the formation ofless stable carbonium ion	(b) resonance stabilisation
(c) larger carbon-halogen bond	(d) inductive effect.

(ii) Which of the following aryl halides is the most reactive towards nucleophilic substitution?

(iii) Which one of the following will react fastest with aqueous NaOH?

The reactivity of the compounds (i) MeBr, (ii) PhCH₂Br, (iii) MeCI, (iv) p- MeOC₆H₄Br decreases as

(a) (i) > (ii) >(iii) > (iv)	(b) (iv) > (ii) >(i) > (iii)
(c) (iv) > (iii) >(i) > (ii)	(d) (ii) > (i) > (iii) > (iv)

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 ofcoordination 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, CO³⁺ forms both inner orbital and outer orbital complexes, with ammonia it forms [Co(NH₃)₆]³⁺ and with fluorine it forms [CoF₆]^3- complex ion.
The following questions are multiple choice questions. Choose the most appropriate answer:
(i) Which of the following is not true for [CoF₆]^3- ?

(a) It is paramagnetic.	(b) It has coordination number of 6.
(c) It is outer orbital complex.	(d) It involves d2sp3 hybridisation.

Which of the following is true for  [Co(NH₃)₆]³⁺ ?

(a) It is an octahedral, dimagnetic and outer orbital complex.

(b) It is an octahedral, paramagnetic and outer orbital complex.

(c) It is an octahedral, paramagnetic and inner orbital complex.

(d) It is an octahedral, dimagnetic and inner orbital complex.

(iii) The paramagnetism of [CoF₆]^3- is due to

(a) 3 electrons

(b) 4 electrons

(c) 2 electrons

(d) 2 electrons

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

(a) \(\left[\mathrm{Ni}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}\)

(b)\(\left[\mathrm{FeF}_{6}\right]^{3-}\)

(c) \(\left[\mathrm{Co}(\mathrm{CN})_{6}\right]^{3-}\)

(d) \(\left[\mathrm{NiCl}_{4}\right]^{2-}\)

Read the passage given below and answer the following questions:
The concentration of potassium ions inside a biological cell is at least twenty times higher than the outside. The resulting potential difference across the cell is important in several processes such as transmission of nerve impulses and maintaining the ion balance. A simple model for such a concentration cell involving a metal M is M_(s) | M⁺(aq.; 0.05 molar) || M⁺(aq; 1 molar) |M_(s).
The following questions are multiple choice questions. Choose the most appropriate answer:
(i) For the above cell,

(a) \(E_{\text {cell }}<0 ; \Delta G>0\)

(b) \(E_{\text {cell }}>0 ; \Delta G<0\)

(c) \(E_{\text {cell }}<0 ; \Delta G^{\circ}>0\)

(d) \(E_{\text {cell }}>0 ; \Delta G^{\circ}<0\)

(ii) The value of equilibrium constant for a feasible cell reaction is

(a) < 1

(b) = 1

(c) > 1

(d) zero

(iii) What is the emf ofthe cell when the cell reaction attains equilibrium?

(a) 1

(b) 0

(c) > 1

(d) < 1

(iv) The potential of an electrode change with change in

(a) concentration of ions in solution	(b) position of electrodes
(c) voltage of the cell	(d) all of these