Recent questions in 2007

Which one of the following polymers is prepared by condensation polymerization ?

asked Jul 26, 2018 by pady_1

1 answer

RNA and DNA are chiral molecules, their chirality is due to :

asked Jul 26, 2018 by pady_1

1 answer

Which one of the following vitamins is water soluble :

asked Jul 26, 2018 by pady_1

2 answers

In the reaction <img src =""/> Which of the following compounds will be formed ?

asked Jul 26, 2018 by pady_1

0 answers

$CH_3-CHCl-CH_2-CH_3$ has a chiral centre, which one of the following represents its R configurations :

asked Jul 26, 2018 by pady_1

1 answer

For the following : (a) $I^-$ (b) $Cl^-$ (c) $Br^-$ The increasing order of nucleophilicity would be :

asked Jul 26, 2018 by pady_1

1 answer

If there is no rotation of plane polarized light by a compound in a specific solvent, through to the chiral, it may mean that :

asked Jul 26, 2018 by pady_1

1 answer

Which of the compounds with molecular formula $C_5H_{10}$ yield acetone on ozonolysis :

asked Jul 26, 2018 by pady_1

1 answer

Predict the product C obtained in the following reaction of butyne-1 : <img src =""/>

asked Jul 26, 2018 by pady_1

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The order decreasing reactivity towards an electrophilic reagent, for the following : (a) Benzene (b) Toluene (c) Chlorobenzene and (d) Phenol Would be :

asked Jul 26, 2018 by pady_1

2 answers

Which one of the following on reduction with lithium aluminium hydride yield a secondary amine:

asked Jul 26, 2018 by pady_1

1 answer

Which one of the following on treatment with 50% aqueous sodium hydroxide yields the corresponding alcohol and acid :

asked Jul 26, 2018 by pady_1

1 answer

Consider the following compounds : (i) $C_6H_5COCl$ (ii) <img src =" "/> The correct decreasing order of their reactivity towards hydrolysis is

asked Jul 26, 2018 by pady_1

1 answer

Reduction of aldehydes and ketones into hydrocarbons using zinc amalgum and conc. HCl is called :

asked Jul 26, 2018 by pady_1

1 answer

The product formed in Aldol condensation is :

asked Jul 26, 2018 by pady_1

1 answer

Which of the following presents the correct order of the acidity in the given compounds :

asked Jul 26, 2018 by pady_1

1 answer

If $NaCl$ is doped with $10^{-4}$ mole % of $SrCl_2$ , the concentrate of cation vacancies will be : $(N_A = 6.02 \times 10^{23}) mol^{-1}$

asked Jul 26, 2018 by pady_1

1 answer

Which of the following will give a pair of enantiomorphs:( $en = NH_2 CH_2 CH_2 NH_2$ )

asked Jul 26, 2018 by pady_1

1 answer

The d electron configuration of $Cr^{2+}, Mn^{2+}, Fe^{2+}$ and $Ni^{2+}$ are $3d^4$ , $3d^5$ , $3d^6$ and $3d^8$ respectively. Which one of the following aqua complex will exhibit the minimum paramagnetic behaviour ? (At. No. Cr = 24, Mn= 25, Fe = 26, Ni = 28)

asked Jul 26, 2018 by pady_1

1 answer

Which one of the following ions is the most stable in aqueous solution ? (At. No. Ti = 22, V = 23, Cr = 24, Mn = 25)

asked Jul 26, 2018 by pady_1

1 answer

Identify the incorrect statement among the following:

asked Jul 26, 2018 by pady_1

1 answer

Which of the following oxidation states are the most characteristic for lead and tin respectively:

asked Jul 26, 2018 by pady_1

1 answer

Which one of the following orders correctly represents the increasing acid strengths of the given acids:

asked Jul 26, 2018 by pady_1

1 answer

Which one of the following anions is present in the chain structure of silicates:

asked Jul 26, 2018 by pady_1

1 answer

Sulphide ores of metals are usually concentrated by Froth Flotation process. Which one of the following sulphide ores offers and exception and is concentrated by chemical leaching ?

asked Jul 26, 2018 by pady_1

1 answer

The correct order of increasing thermal stability of $K_2CO_3, MgCO_3, CaCO_3$ and $BeCO_3$ is:

asked Jul 26, 2018 by pady_1

1 answer

Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true :

asked Jul 26, 2018 by pady_1

1 answer

In which of the following the hydration energy is higher than the lattice energy:

asked Jul 26, 2018 by pady_1

1 answer

Which one of the following ionic species has the greatest proton affinity to form stable compound:

asked Jul 26, 2018 by pady_1

1 answer

The correct order of C-O bond length among $CO, CO^{2-}_3, CO_2$ is :

asked Jul 26, 2018 by pady_1

2 answers

In which of the following pairs, the two species are iso-structural ?

asked Jul 26, 2018 by pady_1

1 answer

Identify the correct order of the size of the following :

asked Jul 26, 2018 by pady_1

1 answer

The fraction of total volume occupied by the atoms present in a simple cube is :

asked Jul 26, 2018 by pady_1

1 answer

A weak acid HA has a $K_a$ of $1.00 \times 10^{-5}$ . If $0.100\; mol$ of this acid is dissolved in one litre of water the percentage of acid dissociated at equilibrium is closest to :

asked Jul 26, 2018 by pady_1

0 answers

Calculate the pOH of a solution at $25^{\circ} C$ that contains $1 \times 10^{-10} M$ of hydronium ions, i.e. $H_3O^+$ ;

asked Jul 26, 2018 by pady_1

1 answer

The following equilibrium constants are given - The equilibrium constant for the oxidation of $NH_3$ by oxygen to give $NO$ is :

asked Jul 26, 2018 by pady_1

0 answers

The Langmuir adsorption isotherm is deduced using the assumption :

asked Jul 26, 2018 by pady_1

1 answer

Given that bond energies of $H-H$ and $Cl-Cl$ are 430 $kJ mol^{-1}$ and 240 $kJ mol^{-1}$ respectively and $\Delta_f H$ for $HCl$ is -90 $kJ mol^{-1}$ . Bond enthalpy of $HCl$ is :

asked Jul 26, 2018 by pady_1

1 answer

Consider the following reactions : $(a) \; H^+_{(aq)} + OH^- _{(aq)} = H_2O_{(l)}, \Delta H = -X_1kJ\; mol^{-1}$ $(b)\; H_{2(g)} + \frac{1}{2} O_{2(g)} = H_2O_{(l)}, \Delta H = -X_2 kJ mol^{-1}$ $(c)\; CO_{2(g)} + H_{2(g)} = CO_{(g)} + H_2O_{(l)} -X_3 kJ mol^{-1}$ $(d)\; C_2H_{2(g)} + \frac{5}{2} O_{2(g)} = 2CO_{2(g)} + H_2O_{(l)} +X_4 kJ mol^{-1}$ Enthalpy of formation of $H_2O_{(l)}$ is:

asked Jul 26, 2018 by pady_1

1 answer

The efficiency of a fuel cell is given by :

asked Jul 26, 2018 by pady_1

1 answer

0.5 molal aqueous solution of a weak acid (HX) is $20 \%$ ionised. If $K_f$ for water is $1.86 K\; kg\; mol^{-1}$ , the lowering in freezing point of the solution is :

asked Jul 26, 2018 by pady_1

1 answer

The equilibrium constant of the reaction : $Cu(s) + 2Ag^+(aq) \to Cu^{2+}(aq) +2Ag(s);$ $E^o = 0.46V$ at 298 K is :

asked Jul 26, 2018 by pady_1

1 answer

If 60% of a first order reaction was completed in 60 minutes, 50% of the same reaction would be completed in approximately : ( $\log 4 = 0.60, \log 5 = 0.69$ )

asked Jul 26, 2018 by pady_1

1 answer

The reaction of hydrogen an iodic monochloride is given as $H_{2(g)} +2ICl_{(g)} \to 2HCl_{(g)}+I_{2(g)}$ Mechanism B : $H_{2(g)} +ICl_{(g)} \to HCl_{(g)}+HI_{(g)}$ ; Slow $HI_{(g)} +ICl_{(g)} \to HCl_{(g)}+I_{2(g)}$ ; Fast Which of the above mechanism(s) can be consistent with the given information about the reaction :

asked Jul 26, 2018 by pady_1

1 answer

In a first order reaction $[A \to B$ ], if $k$ is rate constant and initial concentration of the reactant A is 0.5 M then the half-life is :

asked Jul 26, 2018 by pady_1

0 answers

The number of moles of $KMnO_4$ that will be needed to react with one mole of sulphite ion in acidic slution is :

asked Jul 26, 2018 by pady_1

1 answer

Consider the following sets of quantum number : Which of the following sets of quantum number is not possible :

asked Jul 26, 2018 by pady_1

1 answer

Concentrated aqueous sulphuric acid is $98\% H_2SO_4$ by mass and has a density of $1.80 g.mL^{-1}$ Volume of acid required to make 1 litre of $0.1 MH_2SO_4$ solution is :

asked Jul 26, 2018 by pady_1

1 answer

An element, X has the following isotopic composition; $^{200}X : 90 \%$ $^{199}X : 8.0 \%$ $^{202}X : 2.0 \%$ The weighted average atomic mass of the naturally - occurring element X is closest to :

asked Jul 26, 2018 by pady_1

1 answer

With which of the following electronic configuration of an atom has the lowest ionization enthalpy :

asked Jul 26, 2018 by pady_1

2 answers

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