Recent questions in 2013

Nylon is an example of-

asked Aug 20, 2018 by pady_1

1 answer

Among the following ethers, which one will produce methyl alcohol on treatment with hot concentrated HI ?

asked Aug 20, 2018 by pady_1

1 answer

Antiseptics and disinfectants either kill or prevent growth of microrganisms. Identify which of the following statements is not true-

asked Aug 20, 2018 by pady_1

1 answer

Which one of the following molecules contains no $\pi$ bond ?

asked Aug 20, 2018 by pady_1

1 answer

Which of the following statements about the interstitial compounds is incorrect ?

asked Aug 20, 2018 by pady_1

1 answer

Which of these is not a monomer for a high molecular mass silicone polymer ?

asked Aug 20, 2018 by pady_1

1 answer

Structure of the compound whose IUPAC name is 3-Ethyl-2-hydroxy-4-methylhex-3-en-5-ynoic acid is :

asked Aug 20, 2018 by pady_1

1 answer

Which of the following is electron-deficient ?

asked Aug 20, 2018 by pady_1

1 answer

$KMnO_4$ can be prepared from $K_2MnO_4$ as per the reaction : $3MnO_4^{2-} + 2H_2O \rightleftharpoons 2MnO_4^- + MnO_2 + 4 OH^-$ . The reaction can go to completion by removing $OH^-$ ions by adding -

asked Aug 20, 2018 by pady_1

1 answer

Which of these is least likely to act as a Lewis base ?

asked Aug 20, 2018 by pady_1

1 answer

In excess of $AgNO_3$ is added to 100 mL of a 0.01 M solution of dichlorotetraaquachrominum (III) chloride. The number of moles of AgCl precipitated would be-

asked Aug 20, 2018 by pady_1

1 answer

$XeF_2$ is isostructural with-

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1 answer

Identify the correct order of solubility in aqueous medium-

asked Aug 20, 2018 by pady_1

1 answer

Which of the following lanthanoid ions is diamagnetic ? (At. No. Ce = 58, Sm = 62, Eu = 63, Yb = 70)

asked Aug 20, 2018 by pady_1

0 answers

Which of the following does not give oxygen on heating ?

asked Aug 20, 2018 by pady_1

1 answer

Reaction by which Benzaldehyde cannot be prepared-

asked Aug 20, 2018 by pady_1

1 answer

The basic structural unit of silicates is -

asked Aug 20, 2018 by pady_1

1 answer

Which of the following structure is similar to graphite ?

asked Aug 20, 2018 by pady_1

1 answer

Which of the following is paramagnetic ?

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1 answer

Which is the strongest acid in the following ?

asked Aug 20, 2018 by pady_1

1 answer

Roasting of sulphides gives the gas X as a byproduct. This is colorless gas with choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic, acts as a reducing agent and its acid has never been isolated. The gas X is -

asked Aug 20, 2018 by pady_1

1 answer

A magnetic moment of 1.73 BM will be shown by one among the following -

asked Aug 20, 2018 by pady_1

1 answer

Dipole - induced dipole interactions are present in which of the following pairs :

asked Aug 20, 2018 by pady_1

1 answer

A metal has a fcc lattice. The edge length of the unit cell is 404 pm. The density of the metal is $2.72 \; g \;cm^{–3}$ . The molar mass of the metal is : [NA Avogadro's constant = $6.02 \times 10^{23} mol^{–1}$ ]

asked Aug 20, 2018 by pady_1

1 answer

Maximum deviation from ideal gas is expected from :

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1 answer

The number of carbon atoms per unit cell of diamond unit cell is -

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1 answer

How many grams of concentrated nitric acid solution should be used to prepare 250 mL of 2.0 M $HNO_3$ ? The concentrated acid is 70 % $HNO_3$ .

asked Aug 20, 2018 by pady_1

1 answer

A button cell used in watches functions as following $Zn(s) + Ag_2O(s) + H_2O (l) \rightleftharpoons 2Ag(s) + Zn^{2+} (aq) + 2OH^- (aq)$ If half cell potentials are $Zn^{2+} (aq) + 2e^- \to Zn (s) ; \; \; \; E^o = -0.76V$ $Ag_2O(s) + H_2O (l) + 2e^- \to 2Ag(s) + 2OH^- (aq),\; \; \; E^o = 0.34 V$ The cell potential will be -

asked Aug 20, 2018 by pady_1

1 answer

Based on equation $E = -2.178 \times 10^{-18} J (\frac{Z^2}{n^2})$ , certain conclucsions are written. Which of them is not correct ?

asked Aug 20, 2018 by pady_1

1 answer

At $25^oC$ molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is $9.54 \; ohm^{-1} cm^2 mol^{-1}$ and at infinite dilution its molar conductance is $238 \; ohm^{-1} cm^2 mol^{-1}$ . The degree of ionisation of ammonium hydroxide at the same concentration and temperature is -

asked Aug 20, 2018 by pady_1

1 answer

A reaction having equal energies of activation for forward and reverse reactions has -

asked Aug 20, 2018 by pady_1

2 answers

A hydrogen gas electrode is made by dipping platinum wire in a solution of HCl of pH = 10 and by passing hydrogen gas around the platinum wire at one atm pressure. The oxidation potential of electrode would be ?

asked Aug 20, 2018 by pady_1

2 answers

What is the activation energy for a reaction if its rate doubles when the temperature is raised from $20^oC$ to $35^oC$ ? (R = 8.314 $J mol^{-1} K^{-1}$ )

asked Aug 20, 2018 by pady_1

2 answers

What is the maximum numbers of electrons that can be associated with the following set of quantum numbers ? n = 3, l = 1 and m = -1

asked Aug 20, 2018 by pady_1

2 answers

The value of Planck's constant is $6.63 \times 10^{-34} Js$ . The speed of light is $3 \times 10^{17} nms^{-1}$ . Which value is closest to the wavelength in nanometer of a quantum of light with frequency of $6 \times 10^{15} s^{-1}$ ?

asked Aug 20, 2018 by pady_1

1 answer

The output (X) of the logic circuit shown in figure will be -

asked Aug 20, 2018 by pady_1

1 answer

In a common emitter (CE) amplifier having a voltage gain G, the transistor used has transconductance 0.03 mho and current gain 25. If the above transistor is replaced with another one with transconductance 0.02 mho and current gain 20, the voltage gain will be -

asked Aug 20, 2018 by pady_1

1 answer

In a n-type semiconductor, which of the following statements is true -

asked Aug 20, 2018 by pady_1

1 answer

A parallel beam of fast moving electrons is incident normally on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statements is correct ?

asked Aug 20, 2018 by pady_1

1 answer

In Young’s double slit experiment, the slits are 2mm apart and are illuminated by photons of two wavelengths $\lambda_1 = 12000 Å$ and $\lambda_2 = 10000 Å$ . At what minimum distance from the common central bright fringe on the screen 2m from the slit will a bright fringe from one interference pattern coincide with a bright fringe from the other ?

asked Aug 20, 2018 by pady_1

1 answer

For a normal eye, the cornea of eye provides a converging power of 40D and the least converging power of the eye lens behind the cornea is 20D. Using this information, the distance between the retina and the corneaeye lens can be estimated to be -

asked Aug 20, 2018 by pady_1

1 answer

A plano convex lens fits exactly into a plano concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive indices $\mu_1$ and $\mu_2$ and R is the radius of curvature of the curved surface of the lenses, then the focal length of the combination is -

asked Aug 20, 2018 by pady_1

1 answer

The wavelength $\lambda_e$ of an electron and $\lambda_p$ of a photon of same energy E are related by -

asked Aug 20, 2018 by pady_1

1 answer

For photoelectric emission from certain metal the cutoff frequency is $ν$ . If radiation of frequency $2ν$ impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass) -

asked Aug 20, 2018 by pady_1

1 answer

A certain mass of Hydrogen is changed to Helium by the process of fusion. The mass defect in fusion reaction is 0.02866 u. The energy liberated per u is – (Given 1 u = 931 MeV)

asked Aug 20, 2018 by pady_1

1 answer

The half-life of a radioactive isotope ‘X’ is 20 years. It decays to another element ‘Y’ which is stable. The two elements ‘X’ and ‘Y’ were found to be in the ratio 1 : 7 in a sample of a given rock. The age of the rock is estimated to be -

asked Aug 20, 2018 by pady_1

1 answer

Ratio of longest wave lengths corresponding to Lyman and Balmer series in hydrogen spectrum is -

asked Aug 20, 2018 by pady_1

1 answer

The condition under which a microwave oven heats up a food item containing water molecules most efficiently is -

asked Aug 20, 2018 by pady_1

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A coil of self-inductance L is connected in series with a bulb B and an AC source. Brightness of the bulb decreases when -

asked Aug 20, 2018 by pady_1

1 answer

A wire loop is rotated in a magnetic field. The frequency of change of direction of the induced e.m.f. is -

asked Aug 20, 2018 by pady_1

2 answers

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