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Chemistry Questions

Copper sulphate solution (250 ml) was electrolyzed using a platinum anode and copper cathode. A constant current of 2 mA was passed for 16 minute. It was found that after electrolysis, the absorbance of the solution was reduced to 50% of its original value. Calculate the concentration of copper sulphate ion in the solution to begin with.

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Copper sulphate solution (250 ml) was electrolyzed using a platinum anode and copper cathode. A constant current of 2 mA was passed for 16 minute. It was found that after electrolysis, the absorbance of the solution was reduced to 50% of its original value. Calculate the concentration of copper sulphate ion in the solution to begin with.

Anonymous User tag : Chemistry 10 Nov, 2019 1 Answer 59 views

A compound is composed of two elements A and B, element A constitute f.c.c. lattice, while B occupy all the tetrahedral voids, in this way another simple cubic is constituted by element B, inside the fcc unit cell of element A. If all the points/particles along any one edge of inner cube of every unit cell, are missing then what is the new empirical formula of the compound

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A compound is composed of two elements A and B, element A constitute f.c.c. lattice, while B occupy all the tetrahedral voids, in this way another simple cubic is constituted by element B, inside the fcc unit cell of element A. If all the points/particles along any one edge of inner cube of every unit cell, are missing then what is the new empirical formula of the compound?

Anonymous User tag : Chemistry 29 Oct, 2019 1 Answer 60 views

hc

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Sample of 2,3 dibromopentane is heat in zinc dust the resulting compound is isolated and heated with hi in presence of p to yield---------

Anonymous User tag : Chemistry 14 Jul, 2019 1 Answer 57 views

In a crystal structure of an element, atoms are present in ccp arrangement and tetrahedral voids, which of the following relation between the atomic radius and edge length is correct for the unit cell which is formed in this arrangement? (a is the edge length and R is the radius of atom)

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In a crystal structure of an element, atoms are present in ccp arrangement and tetrahedral voids, which of the following relation between the atomic radius and edge length is correct for the unit cell which is formed in this arrangement? (a is the edge length and R is the radius of atom)

Anonymous User tag : Chemistry 12 Jul, 2019 1 Answer 63 views

The electron of hydrogen atom was excited from ground state to a higher orbit. During de-excitation of the electron, photons of six different wavelengths were emitted. If each photon forms a spectral line, how many spectral line will be visible to naked eye?

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The electron of hydrogen atom was excited from ground state to a higher orbit. During de-excitation of the electron, photons of six different wavelengths were emitted. If each photon forms a spectral line, how many spectral line will be visible to naked eye?

Anonymous User tag : Chemistry 23 Jun, 2019 1 Answer 61 views

For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia was absorbed in 60 mL of M/10 sulphuric acid. The unreacted acid required 20 mL of M/10 sodium hydroxide for complete neutralization. The percentage of nitrogen in the compound is ?

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For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia was absorbed in 60 mL of M/10 sulphuric acid. The unreacted acid required 20 mL of M/10 sodium hydroxide for complete neutralization. The percentage of nitrogen in the compound is ?

Rahul Kumar tag : Chemistry 21 Jun, 2019 1 Answer 116 views

equilibrium-The equilibrium constant of the reaction CH3COOH (l)+C2H5OH (l)=CH3COOC2H5+H2O is 4.if one mole of each of acetic acid and ethyl alcohol are heated in presence of little concentrated H2SO4 at equilibrium the amount of ester present is

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The equilibrium constant of the reaction CH3COOH (l)+C2H5OH (l)=CH3COOC2H5+H2O is 4.if one mole of each of acetic acid and ethyl alcohol are heated in presence of little concentrated H2SO4 at equilibrium the amount of ester present is

Anonymous User tag : Chemistry 28 May, 2019 1 Answer 205 views

solid state

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 an elemental crystal has a density of 8570kgm3 the packing efficiency is 0.68 if closest distance b/w neighbouring atom is 2.86 angstrom the mass of 1 atom

Anonymous User tag : Chemistry 22 May, 2019 1 Answer 75 views

An organic compound is found to contain C, H and O as elements. It is soluble in water. chars with conc. sulphuric acid and also gives purple colour and Molisch reagent. The solution test is negative but it forms a blue colour with iodine. The organic compound should be

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An organic compound is found to contain C, H and O as elements. It is soluble in water. chars with conc. sulphuric acid and also gives purple colour and Molisch reagent. The solution test is negative but it forms a blue colour with iodine. The organic compound should be?

Anonymous User tag : Chemistry 06 May, 2019 1 Answer 59 views

0.6 mL of acetic acid (CH3COOH), having density 1.06 g mL–1, is dissolved in 1 litre of water. The depression in freezing point observed for this strength of acid was 0.0205°C. Calculate the van’t Hoff factor and the dissociation constant of acid

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0.6 mL of acetic acid (CH3COOH), having density 1.06 g mL–1, is dissolved in 1 litre of water. The depression in freezing point observed for this strength of acid was 0.0205°C. Calculate the van’t Hoff factor and the dissociation constant of acid.

Anonymous User tag : Chemistry 04 May, 2019 1 Answer 371 views

1.00 g of a non-electrolyte solute dissolved in 50 g of benzene lowered the freezing point of benzene by 0.40 K. The freezing point depression constant of benzene is 5.12 K kg mol–1. Find the molar mass of the solute

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1.00 g of a non-electrolyte solute dissolved in 50 g of benzene lowered the freezing point of benzene by 0.40 K. The freezing point depression constant of benzene is 5.12 K kg mol–1. Find the molar mass of the solute

Anonymous User tag : Chemistry 04 May, 2019 1 Answer 54 views

1.00 g of a non-electrolyte solute dissolved in 50 g of benzene lowered the freezing point of benzene by 0.40 K. The freezing point depression constant of benzene is 5.12 K kg mol–1. Find the molar mass of the solute

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1.00 g of a non-electrolyte solute dissolved in 50 g of benzene lowered the freezing point of benzene by 0.40 K. The freezing point depression constant of benzene is 5.12 K kg mol–1. Find the molar mass of the solute

Rajkumar Yadav tag : Chemistry 01 May, 2019 1 Answer 96 views

The boiling point of benzene is 353.23 K. When 1.80 g of a non-volatile solute was dissolved in 90 g of benzene, the boiling point is raised to 354.11 K. Calculate the molar mass of the solute. Kb for benzene is 2.53 K kg mol–1

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The boiling point of benzene is 353.23 K. When 1.80 g of a non-volatile solute was dissolved in 90 g of benzene, the boiling point is raised to 354.11 K. Calculate the molar mass of the solute. Kb for benzene is 2.53 K kg mol–1 

Rajkumar Yadav tag : Chemistry 01 May, 2019 1 Answer 88 views

The vapour pressure of pure benzene at a certain temperature is 0.850 bar. A non-volatile, non-electrolyte solid weighing 0.5 g when added to 39.0 g of benzene (molar mass 78 g mol-1). Vapour pressure of the solution, then, is 0.845 bar. What is the molar mass of the solid substance?

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The vapour pressure of pure benzene at a certain temperature is 0.850 bar. A non-volatile, non-electrolyte solid weighing 0.5 g when added to 39.0 g of benzene (molar mass 78 g mol-1). Vapour pressure of the solution,
then, is 0.845 bar. What is the molar mass of the solid substance?

Anonymous User tag : Chemistry 01 May, 2019 1 Answer 122 views

Vapour pressure of chloroform (CHCl3) and dichloromethane (CH2Cl2) at 298 K are 200 mm Hg and 415 mm Hg respectively. (i) Calculate the vapour pressure of the solution prepared by mixing 25.5 g of CHCl3 and 40 g of CH2Cl2 at 298 K and, (ii) mole fractions of each component in vapour phase.

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Vapour pressure of chloroform (CHCl3) and dichloromethane (CH2Cl2) at 298 K are 200 mm Hg and 415 mm Hg respectively. (i) Calculate the vapour pressure of the solution prepared by mixing 25.5 g of CHCl3 and 40 g of H2Cl2 at 298 K and, (ii) mole fractions of each component in vapour phase.

Anonymous User tag : Chemistry 01 May, 2019 1 Answer 1228 views

If N2 gas is bubbled through water at 293 K, how many millimoles of N2 gas would dissolve in 1 litre of water. Assume that N2 exerts a partial pressure of 0.987 bar. Given that Henry’s law constant for N2 at 293 K is 76.48 kbar.

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If N2 gas is bubbled through water at 293 K, how many millimoles of N2 gas would dissolve in 1 litre of water. Assume that N2 exerts a partial pressure of 0.987 bar. Given that Henry’s law constant for N2 at 293 K is
76.48 kbar.

Anonymous User tag : Chemistry 01 May, 2019 1 Answer 653 views

X-ray diffraction studies show that copper crystallises in an fcc unit cell with cell edge of 3.608×10-8 cm. In a separate experiment, copper is determined to have a density of 8.92 g/cm3, calculate the atomic mass of copper

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X-ray diffraction studies show that copper crystallises in an fcc unit cell with cell edge of 3.608×10-8 cm. In a separate experiment, copper is determined to have a density of 8.92 g/cm3, calculate the atomic mass of copper

Rajkumar Yadav tag : Chemistry 19 Apr, 2019 1 Answer 59 views

A 200 mL of solution of I2 is divided into two unequal parts. I part reacts with hypo solution in acidic medium, 30 ml of 0.2 M hypo was consumed, II part was added with 50 mL of 0.6 M NaOH solution. What was the initial concentration of I2.

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A 200 mL of solution of I2 is divided into two unequal parts. I part reacts with hypo solution in acidic medium, 30 ml of 0.2 M hypo was consumed, II part was added with 50 mL of 0.6 M NaOH solution. What was the initial concentration of I2.

Anonymous User tag : Chemistry 07 Apr, 2019 1 Answer 126 views

Potassium. The name is derived from the english word potash. The chemical symbol K comes from kalium, the Mediaeval Latin for potash, which may have derived from the arabic word qali, meaning alkali. Potassium is a soft, silvery-white metal, member of the alkali group of the periodic chart.

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Potassium. The name is derived from the english word potash. The chemical symbol K comes from kalium, the Mediaeval Latin for potash, which may have derived from the arabic word qali, meaning alkali. Potassium is a soft, silvery-white metal, member of the alkali group of the periodic chart.
 

Anonymous User tag : Chemistry 11 Jul, 2018 1 Answer 59 views

Based on the statements given here choose the correct answer.

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Based on the statements given here choose the correct answer.

P.Gases can be cooled and converted into liquid below its critical temperature by increasing the pressure on it.

Q.Above the critical temperature, a gas (vapour) can not be liquefied however great the pressure it is subjected to

(A)Both P and Q are true and Q explain P

(B)Both P and Q are the true but Q cannot explains P

(C)Only P is true

(D)Q is true

Anonymous User tag : Chemistry 13 Jun, 2018 1 Answer 59 views

Classify the following solids in different categories based on the nature of intermolecular forces operating in them: Potassium sulphate, tin, benzene, urea, ammonia, water, zinc sulphide, graphite, rubidium, argon, silicon carbide.

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Classify the following solids in different categories based on the nature of intermolecular forces operating in them: Potassium sulphate, tin, benzene, urea, ammonia, water, zinc sulphide, graphite, rubidium, argon, silicon carbide.

Anonymous User tag : Chemistry 24 Feb, 2018 1 Answer 307 views

In Dumas' method of estimation of nitrogen 0.35 g of an organic compound gave 55 mL of nitrogen collected at 300 K temperature and 715 mm pressure. The percentage composition of nitrogen in the compound would be (Aqueous tension at 300 K = 15 mm) ?

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In Dumas' method of estimation of nitrogen 0.35 g of an organic compound gave 55 mL of nitrogen collected at 300 K temperature and 715 mm pressure. The percentage composition of nitrogen in the compound would be (Aqueous tension at 300 K = 15 mm) ?

Yogesh Mangal tag : Chemistry 09 Jan, 2018 1 Answer 663 views

The colour of the X2 molecules of group 17 elements changes gradually from yellow to violet down the group. This is due to?

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The colour of the X2 molecules of group 17 elements changes gradually from yellow to violet down the
group. This is due to


[A] the physical state of X2 at atom temperature changes from gas to solid down the group


[B] decrease in HOMO-LUMO gap down the group


[C] decrease in  gap down the group


[D] decrease in ionization energy down the group

Rahul Kumar tag : Chemistry 30 Dec, 2017 1 Answer 345 views