A to Z Exams

Which of the following is an example of interstitial hydride

Given that ∆Hf(H) = 218 k J / mol, express the H - H bond energy in k cal/mol

The earthy impurities present in the mineral are called

On passing a current through molten KCl 19.5 of K is deposited. The amount of aluminium deposited by the same quantity of electricity if passed through molten AlCl3 is

X,Y,Z hydrocarbons molecular formula are CH4, C2H4, C2H2, these three are passed through porcelain tube containing ammonical cuprous chloride. The out coming gases would be

Assertion (A) : At 300 K,kinetic energy of 16 g of methane is equal to the kinetic energy of 32 g of oxygen. Reason (R) : At constant temperature,kinetic energy of one mole of all gases is equal. The correct answer is:

The equilibrium constant for the reaction is 6.The initial concentration of each of CH3COOH and C2H2OH is two(mole/lit).What is the concentration of CH3COOC2H5 at equilibrium in moles /lit

When aniline is treated with CHCI3 and KOH, the product is :

Beryllium shows diagonal relationship with aluminium.Which one of the following similarity is not correct

Assertion(A): A catalyst has no effect on the state of equilibrium Reason:A catalyst influences the rates of both forward and backward reactions to the same extent

Which one of the following is used as an acid flux in metallurgy ?

In the reaction AlCl3+Cl-→AlCl4-, AlCl3 is

Which of the following is correct

Exhausted permutit does not contain .... ion :

Oxidation number of oxygen in OF2 is

A(g)+2B(g)⇔2C(g)+D(g) was studied using an initial concentration of B which was 1.5 times that of A .But the equilibrium concentrations of A and B were found to be equal .Then Kc for the equilibrium

The gold numbers of three protective colloids A, B, and C are 0.05, 0.01 and 0.5 respectively. The decreasing order of their protective power is:

In the extraction of iron from haematite,the charge used is haematite,coke and lime stone in the following weight ratio

What are the metal ions present in carnallite ?

H3O++OH-→2H2O

Bhopal gas tragedy of 1984 was caused by

Carbogen to

When a sample of gas expands from 4.0L to 12.0L against a constant pressure of 0.30 atm, the work involved is (1L ATM=101.35 J)

The number of oxygen atoms bonded to one phosphorus atom in P4O6 is:

The order of decrease in atomic radii for Be;Na;Mg is

Assertion (A) : Equal moles of different substances contain same number of constituent particles.Reason (R) : Equal weights of different substances contain the same number of constituent particles.The correct answer is

The equilibrium constant for the reaction H2(g)+I2(g)⇔2HI(g) is 81 at a certain temperature.If the concentrations of H2 and I2 are 3mole.lit each at equilibrium,the equilibrium concentration of HI is

The half-life period of a radioactive substance is 150 days. Starting with an initial quantity of 1 mg of the substance the fraction of that has disintegrated in 600 days is

Which of the following is not correct

CH3COOH ----LiAlH4--->  AA + CH3COOH ---H3O+ ----->  B + H2OIn the above reactions 'A' and 'B' respectively are

The charge present onn one azide ion in columbs is

An organic compound containing C and H has 92.3% of carbon, Its empirical formula is:

Which one of the following compounds in aqueous solution gives a white precipitate with perichloric acid ?

In which of the following reactions, the concentration of product is higher than the concentration of reactant at equilibrium (K=equilibrium constant)

During the electrolysis of cyrolite,aluminium and fluorine are formed in.......molar ratio

The bonds in K4Fe(CN)6 are:

For the reversible reaction C2H4 + H2 ⇔ C2H6 the equilibrium constant can be expressed in units of

One mole of fluorine is reacted with two moles of hot concentrated KOH. The products formed are KF, H2O and O2. The molar ratio of KF, H2O and O2 respectively is

The standard reduction electrode potential values of the elements A, B and C are +0.68V, -2.5V and -0.5V respectively. The order of their reducing power is

The number of pπ - dπ 'pi' bonds present in XeO3and XeO4molecules, respectively are

Which of the following statements is not correct ?

In lime kiln the reaction CaCO3(s)⇔CaO(s)+CO2(g)

Which of the following is a linear molecule

At 270C the ratio of root mean square velocities of ozone to oxygen is :

Chloroethane reacts with Y to form NaCl and Z. One mole of Z reacts with two moles of HI to form water and iodo ethane. Which of the following is Y

Ordinary glass is a combination of the following

The charge required to reduce 1 mole Cr2O7-2 to Cr+3 ions is

At 270C, 500 mL of helium diffuses in 30 minutes. What is the time (in hours) taken for 1000 mL of SO2 to diffuse under same experimental conditions ?

The decreasing order of bond dissociation  energies of   C-C , C-H and H-H i bond is

For a given reaction which one is higher than the rest among the following

Resonance in benzene is accompanied by delocalization of π –electrons. Each π electron is attached with

Which of the following is used for making optical instruments ?

If in a 100 mL of an aqueous HC1 of pH 1.00, 900 mL of more distilled water is added, the pH of the resultant solution will be :

Number of coulombs of current required to convert completely 1 mole of MnO4-ions in acid medium to one mole of Mn2+ions electrolytically is

Assertion (A): The PH of a buffer solution containing equal moles of acetic acid and sodium acetate is 4.8  (pKa of acetic acid is 4.8)Reason (R): The ionic product of water at  250C is l0-14 mol2 .L-2. The correct answer is

A sample of gas has a volume of 0.2 lit. measured at 1 atm. pressure and 00C. At the same pressure, but at 2730C its volume will become

In the reaction BCl3+PH3→[Cl3B←PH3] the lewis base is

Solubility product of Ba(OH)2 and Al(OH)3 are 1.8x10-10 and 2.4x10-20 respectively.If both Al3+ and Ba+2 ions are present is a solution,which one will be precipated on addition of Ammonium hydroxide solution

The chemical formula of feldspar is

Three faradays of electricity are passed through molten Al2O3,aqueous solution of CuSO4 and molten NaCl taken in three different electrolytic cells.The amount of Al,Cu and Na deposited at cathodes will be in the ratio

A and B are ideal gases. The molecular weights of A and B are in the ratio of 1 : 4. The pressure of a gas mixture containing equal weights of A and B is P atm. What is the partial pressure (in atm) of B in the mixture ?

Absolute alcohol (100% alcohol) is prepared by distilling rectified spirit over:

The oxidation state of Mo in MO2 (Cl8)4- ion is

In nuclear reactor, heavy water is used as a :

The metal used for the de-bromination reaction of 1, 2 dibromoethane

 Fluorine reacts with dilute NaOH and forms a gaseous product A. The bond angle in the molecule of A is

Identify the reaction for which ΔH ≠ ΔE :

The equilibrium constants for the reactions N2(g)+O2(g)⇔2NO(g) and NO(g)+1/2O2(g)⇔NO2(g) are K1 and K2 respectively. Then the equilibrium constant for the reaction N2(g)+2O2(g)⇔2NO2(g) is

Method used for the concentration of tinstone ore is

A sample of 100ml water required 0.294mg of K2Cr2O7(mol.wt=294)for oxidizing dissolved organic compounds in it. The C.O.D of water sample is

Calculate ∆H0 for the reaction Na2O(s) + SO3 (g)→ Na2SO4(g) given the following1. Na(s) + H2O(l) →NaOH (s)+ 1/2 H2(g) ∆H0  = -146kJ2.Na2SO4(s) + H2O(l) →2NaOH(s) + SO3(g) ∆H0  = +418kJ3. 2Na2O(s) + 2H2(g) →4Na (s) + 2 H2O(l) ∆H0 = +259kJ

3-hydroxybutanal is formed when (X) reacts with (Y) in dilute (Z) solution. Whatare X, Y and Z

'Natalite' is used as

 Which of the following is not correct

The conjugate acid of SO42- is

The heat of formation of HI from the equation H2+I2→2HI,ΔH=+52 KJ is

The number of structural alcoholic isomers for C4H10O is

Conjugate base of H2SO4 is

The chemicals and the reaction conditions required for the preparation of ethane are

CH2=CH2+HCl→CH3CH2Cl is an example for

For the redox reaction Cr2O72+ + C2O42+ + H+ → Cr3+ + CO2 + H2O the correct coefficients of Cr2O72-, C2O42- and H+ in the balanced equation are

Anhydrous Magnesium chloride can be prepared by heating MgCl2.2H2O

The correct order of reducing abilities of hydrides of V group elements is

Which one of the following compounds liberates CO2 from aqueous NaHCO3

Which of the following set of variables give a straight line with a negative slope when plotted ?(P - vapour pressure, T = Temperature in K)

Ethylene reacts with Br2 in CCl4 to from X. When X is reacted with alcoholic KOH. Y is formed. Here X and Y are

5.85 gms of NaCl (Mol. wt. 58.5) is dissolved in water and the solution made up to 500ml; the molarity of the solution will be

The   IUPAC    name    of   the    compound(CH3)2CH-CH=CH-CHOH-CH3 is

PH of a solution produced when aqueous solution of PH 6 is mixed with an equal volume of an aqueous solution oh PH is about

What is the time (in sec) required for depositing all the silver present in 125mL of 1 M AgN03 solution by passing a current of 241.25 A ? (1 F = 96500 coulombs)

When the same amount of zinc is treated with excess of H2SO4 and with excess NaOH, the ratio of the volume of H2 evolved is

1 mole of PCl5 is heated with 0.2 mole of chlorine in a one litre vessel till equilibrium is established. At equilibrium if 0.8 mole of chlorine in the vessel, the value of equilibrium constant for the dissociation of PCl5 is (in moles-lit-1)

The conjugate base of HSO4- ion is:

9.8 g of H2SO4is present in two litres of a solution.The molarity of the solution is:

The experimental data for the reaction 2NO(g)+Cl2(g)→2NOCl(g) are given below Expt [Cl2] [NO] Initial rate 1 0.020 0.010 2.4x10-4 2 0.020 0.030 2.16x10-3 3 0.040 0.030 4.32x10-3 What is the order of the reaction

Which of the following is added to chloroform to slow down its aerial oxidation in presence of light ?

8 gram of NaOH is mixed with 9.8 gram of H2SO4 in litre of solution the pH of the solution is

In which of the following cases, the reaction is spontaneous at all temperatures

Which of the following halide does not contain a lone pair of electrons on the central atom

Which of the following is not correct