A to Z Exams

The hemoglobin from the red blood corpuscles of most mammals contains approximately 0.33% of iron by weight. The molecular weight of hemoglobin as 67200.the number of iron atoms in each molecule of hemoglobin is (atomic weight of iron = 56)

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

Which one of the following noble gases is used in miner's cap lamps

Which of the following is not correct

Which of the following reacts with ethanol to form chloroform

Which of the following not obtained when methyl chloride and n-propyl chloride react with sodium in dry ether

Which of the following alkali metals has the greatest tendency for the half reaction;  M(g) →M+(aq) + e

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

Which of the following is the anhydride of HNO3

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

The conjugate acid of NH2- ion 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

Vicinal dihalide (C2H4Br2) on heating with excess alc.KOH and Zinc dust gives ’y’ and ‘z’ respectively. Both ‘y’ and ’z’ on oxidation with Bayer’s regent gives A and B.A and B respectively are

A radio isotope has a half life 10 days.If today there is 125g of it left,what was its weight 40 days earlier?

The Chemical reaction between NaS2O3 and I2 leads to the formation of

 Which of the following is a pair of functional isomers

In which of the following reactions the product is an ether

The following are some statements related to VA group hydrides,I . Reducing  property increases from NH3 to BiH3.II..Tendency to donate lone pair decreases from NH3 to BiH3III.Thermal stability of hydrides decreases from NH3 to BiH3.IV. Bond angle of hydrides decreases from NH3 to BiH3.The correct statements are

The hydronium ion concentration of a solution is 1X10-4 M at 250 C.The hydroxide ion concentration in the same solution is

Which of the following pair of ions have same paramagnetic moment

An organic compound X on treatment with pyridium dichromate in dichloromethane gives compound Y.Compound Y reacts with I2 and alkali to form idoform.The compound X is

Which of the following is not a conjugate acid-base pair

A solution of concentration "C" g equiv/litre has a specific resistance R, The equivalent conductance of the solution is

The number of sigma and pi (π) bonds present in benzene respectively are :

Which one of the following is a secondary alcohol ?

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 ?

The earthy impurities present in the mineral are called

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

Which one of the following salts give an acidic solution in water

Identify the correct decreasing order of the following with respect to altitude from atmosphere:I. Troposphere    II. Mesosphere  III. Thermosphere

when acetaldehyde is heated with Fehling solution, a red precipitate is formed. Which of the following is that

Hydrolysis of chloroform with aqueous KOH gives finally

The Kc for the reaction A+B↔C is 4 and Kc for 2A+D↔C is 6. The value of Kc for C+D↔2B 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

Identify the reaction for which ΔH ≠ ΔE :

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

Active mass of 56 g of N2 contained in 2 ltr.Flask is

On adding a little phosphorous to silicon, we get a/an

All the three oxygen atoms of ozone are utilized in the oxidation of

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

The rate of gaseous reaction is give by k[A][B].If the volume of reaction vessel is reduced to 1/4 of initial volume the reaction rate relative to the original rate is

Increasing the conc. of the reactant by 27 times, the rate increases by 3 times. What is the order of the reaction?

The number of structural alcoholic isomers for C4H10O is

The molar capacity(Cp)of water at constant pressure is 75 J.K-1.mol-1.The increase in temperature (in K) of 100 g of water when 1 K.J. of heat is supplied to it is

The functional groups present in 'salol' are

Which of the following statements is NOT correct?

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

The standard reduction potentials of Zn2- | Zn, Cu2+| Cu and Ag+| Cu and Ag+| Ag are respectively -0.76, 0.34 and 0.8 V. The following cells were constructed :1) Zn | Zn 2+||Cu 2+| Cu2) Zn | Zn 2+||Ag +| Ag3) Cu | Cu 2+||Ag +| Agwhat is the correct order of Eocell of these cells?

Hydrolysis of sucrose with dilute aqueous sulphuric acid yields

Which of the following is a biodegradable polymer

Which one of the following equation is correct for the reaction N2(g)+3H2(g)→2NH3(g)

Alcohol manufactured from water gas is

Zn(s)+Cu+2(ag)→Cu(s)+Zn+2(ag)Given that ΔfG0 for Cu+2(ag) and Zn+2(ag) are +65.0 K.J.mol-1 and -147.2 K.J.mol-1 respectively then the standard Gibbs energy change for the above reaction is

List -I List-II (A) Flespar (I) [Ag3SbS3] (B) Asbestos (II) Al2O3 . H2O (C) Pyrargyrite (III) MgSO4 . H2O (D) Diaspore (IV) KAlSi3O3 (V) CaMg3(SiO3)4

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)

Which of the following is not correct regarding the properties of ionic compounds ?

Aqueous solution of an organic compound, 'A' on electrolysis liberates acetylene and CO2 at anode. 'A' is

When 9.65 Coulombs of electricity is passed through a solution of AgN03 (atomic weight of silver 108), the amount of silver deposited is

Which among the following element does not liberate H2 gas on reaction with NaOH?

The vapour pressure of water at 230C is 19.8 mm. 0.1 mole of glucose is dissolved in 178.2 g of water. What is the vapour pressure (in mm) of the resultant solution

Study the following table: Buffer solution Volume(in ml) of 0.M weak Volume(in ml) of 0.1 M sodium salt of weak acid I 4.0 4.0 II 4.0 40.0 III 40.0 4.0 IV 0.1 10.0 Which of the two sets of buffer solutions have least pH?

Oxidation number of oxygen in OF2 is

What is the hybridization state of the central atom in the conjugate acid of NH3?

The two sulphur atoms in Na2S2O3 have

A molecule (X ) has (i) four sigma bonds formed by the overlap of sp2 and s orbitals (ii) one sigma bond formed by sp2 and sp2 orbitals and (iii) one π bond formed by px and pz orbitals. Which of the following is X ?

List-I List-II List-III CH3COONa Alc.KOH Ethylene CHCl2-CHCl2 H2O Acetylene C2H5MgI NaOH+CaO Methane CH3-CH2Cl Zn dust Ethane The correct match is

Observe the following statements :I.   Bleaching   powder   is   used   in   the preparation of chloroform.II.  Bleaching powder decomposes in the presence ofCoCl2 to liberate 02.III.Aqueous KHF2 is used in the preparation of fluorine.The correct combination is :

Which of the following is correct

Which of the following is not correct

Oxide of nitrogen which gives reddish brown colour when exposed to air is

In the Dewar's method of separation of noble gases, the mixture of noble gases is kept in contact with coconut charcoal at 173K. Which one of the following gaseous mixtures is not adsorbed on to the charcoal ?

The flux used in the extraction of iron from Haematite in the blast furnace 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

In nuclear reactor, heavy water is used as a :

The atomic numbers of elements X, Y and Z are 19, 21 and 25 respectively. The number of electrons present in the M shell of these elements follow the order

Which one of the following reactions does not form gaseous product

In 0.01 M solution,HCN is 0.01% ionized. Its dissociation constant is

The conjugate acid of SO42- is

138 g of ethyl alcohol is mixed with 72 g of water. The ratio of mole fraction of alcohol to water is

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

In aqueous solutions H2O2 oxidises H2S to

'Natalite' is used as

The difference in ΔH and ΔE for the combustion of methane at 270C would be

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 the cathodes will be in the ratio of

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

Identify the correct order in which the covalent radius of the following elements increasesI. TiII. CaIII. Sc

The molarity of pure water is:

The molar concentrations of A,B and C at equilibrium for the reaction A+2B⇔3C are 2,3 and 4 moles/lit respectively. Its Kc is

The value of Kc for the reaction N2+3H2 ⇔2NH3 depends on

Among  the following, which is water insoluble

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:

Hybridization at 2nd carbon in CH2 = CH – CH3 is

A certain sample of gas has a volume of 0.2 litres measured at 1 atm. pressure and 00 C. At the same pressure but at 273 0c. Its volume will be

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 correct order of reducing abilities of hydrides of V group elements 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

5 moles of acid is required to change the pH of 1 litre of buffer by 2units.Find buffer capacity.

If ΔE is the heat of reaction for C2H5OH(1)+3O2(g)→2CO2(g)+3H2O(l) at constant volume,the ΔH(Heat of reaction at constant pressure)at constant temperature is

Calculate the emf of the cell   Cu (s) | Cu2+ (aq) || Ag+ (aq) | Ag (s)  GivenEoCu2+/Cu  = +0.34V ,  EoAg+/Ag  =0.80 V

If the length of the unit cell is 5 Ao. the smallest distance in Ao between the two neighbouring metal atoms in a face centred cubic lattice is