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Chemistry Questions

2 g of a gas A is introduced into an evacuated flask kept at 25°C. The pressure is found to be 1 atm. If 3 g of another gas B is added to the same flask the total pressure becomes 1.5 atm, assuming ideal gas behaviour. The ratio of molecular weight of gas A to gas B (MA : MB) is

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2 g of a gas A is introduced into an evacuated flask kept at 25°C. The pressure is found to be 1 atm. If 3 g of another gas B is added to the same flask the total pressure becomes 1.5 atm, assuming ideal gas behaviour. The ratio of molecular weight of gas A to gas B (MA : MB) is

Anonymous User tag : Chemistry State of matter 05 Apr, 2020 1 Answer 52 views

50 ml of mixture of NH3 and H2 are decomposed to yield N2 and H2 and to the resulting mixture 40 ml O2 is added and the mixture is sparked to yield H2O. When the resulting mixture of gases were passed through alkaline pyrogallol 6 ml contraction was observed. Calculate the percentage composition of NH3 in the original mixture

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50 ml of mixture of NH3 and H2 are decomposed to yield N2 and H2 and to the resulting mixture 40 ml O2 is added and the mixture is sparked to yield H2O. When the resulting mixture of gases were passed through alkaline pyrogallol 6 ml contraction was observed. Calculate the percentage composition of NH3 in the original mixture

Anonymous User tag : Chemistry State of matter 05 Apr, 2020 1 Answer 52 views

A 10 cm air column is trapped inside the tube (having uniform area of cross section) by 6 cm of Hg and is placed horizontally to the plane. Calculate the length of air column when the tube is placed vertically with opened end up.

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A 10 cm air column is trapped inside the tube (having uniform area of cross section) by 6 cm of Hg and is placed horizontally to the plane. Calculate the length of air column when the tube is placed vertically with opened end up.

Anonymous User tag : Chemistry State of matter 05 Apr, 2020 1 Answer 52 views

A vertical hollow cylinder of height 152 cm is fitted with a weightless piston. The lower half is filled with an ideal gas and the upper half with mercury.The cylinder is now heated at300K,so that 1/4th of the mercury comes out.Find the temperature at which it will happen assuming thermal expansion of Hg to be negligible

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A vertical hollow cylinder of height 152 cm is fitted with a weightless piston. The lower half is filled with an ideal gas and the upper half with mercury.The cylinder is now heated at300K,so that 1/4th of the mercury comes out.Find the temperature at which it will happen assuming thermal expansion of Hg to be negligible

Anonymous User tag : Chemistry State of matter 05 Apr, 2020 1 Answer 52 views

1 mole of gas H2 and 4 moles of gas O2 is taken inside the vessel, which effuse through a small orifice of the vessel having same area of cross section and at the same temperature, then which is the correct % of effused volume of gas H2 and O2 initially respectively? (Assume that the gas H2 does not react with O2 gas)

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1 mole of gas H2 and 4 moles of gas O2 is taken inside the vessel, which effuse through a small orifice of the vessel having same area of cross section and at the same temperature, then which is the correct % of effused volume of gas H2 and O2 initially respectively? (Assume that the gas H2 does not react with O2 gas)

Anonymous User tag : Chemistry State of matter 05 Apr, 2020 1 Answer 52 views

Explain the following a) Although Au is soluble in aqua-regia, Ag is not b) Zinc and hot copper is used for recovery of Ag from the complex [Ag(CN)2]– c) Aluminium metal is frequently used as a reducing agent for extraction of metal such as chromium manganese etc. d) Partial roasting of sulphide ore is done in the metallurgy of copper.

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Explain the following
a) Although Au is soluble in aqua-regia, Ag is not
b) Zinc and hot copper is used for recovery of Ag from the complex [Ag(CN)2]–

c) Aluminium metal is frequently used as a reducing agent for extraction of metal such as chromium manganese etc.

d) Partial roasting of sulphide ore is done in the metallurgy of copper.

Anonymous User tag : Chemistry Matallurgy 31 Mar, 2020 1 Answer 60 views

Solubility product of silver bromide is 5.0 × 10–13. The quantity of potassium bromide (molar mass taken as 120 g mol–1) to be added to 1 litre of 0.05 M solution of silver nitrate to start the precipitation of AgBr is

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Solubility product of silver bromide is 5.0 × 10–13. The quantity of potassium bromide (molar mass taken as 120 g mol–1) to be added to 1 litre of 0.05 M solution of silver nitrate to start the precipitation of AgBr is

Anonymous User tag : Chemistry Equilibrium 29 Mar, 2020 1 Answer 55 views

29.5 mg of an organic compound containing nitrogen was digested according to Kjeldahl's method and the evolved ammonia was absorbed in 20 mL of 0.1 M HCl solution. The excess of the acid required 15 mL of 0.1 M NaOH solution for complete neutralisation. The percentage of nitrogen in the compound is?

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29.5 mg of an organic compound containing nitrogen was digested according to Kjeldahl's method and the evolved ammonia was absorbed in 20 mL of 0.1 M HCl solution. The excess of the acid required 15 mL of 0.1 M NaOH solution for complete neutralisation. The percentage of nitrogen in the compound is?

Anonymous User tag : Chemistry 29 Mar, 2020 1 Answer 56 views

In a multi­electron atom, which of the following orbitals described by the three quantum numbers will have the same energy in the absence of magnetic and electric fields? (i)  n=1,l=0,m=0 (ii)  n=2,l=0,m=0 (iii)  n=2,l=1,m=1 (iv)  n=3,l=2,m=1 (v)  n=3,l=2,m=0

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In a multi­electron atom, which of the following orbitals described by the three quantum numbers will have the same energy in the absence of magnetic and electric fields?

(i)  n=1,l=0,m=0

(ii)  n=2,l=0,m=0

(iii)  n=2,l=1,m=1

(iv)  n=3,l=2,m=1

(v)  n=3,l=2,m=0

Anonymous User tag : Chemistry Structure of Atom 24 Mar, 2020 1 Answer 52 views

Benzene and toluene form nearly ideal solutions. At 20°C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20°C for a solution containing 78 g of benzene and 46 g of toluene in torr is

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Benzene and toluene form nearly ideal solutions. At 20°C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20°C for a solution containing 78 g of benzene and 46 g of toluene in torr is

Anonymous User tag : Chemistry Solutions 15 Mar, 2020 1 Answer 50 views

An organic liquid with sweet smell and b.pt 78°C contains C, H and O. On heating with conc. H2SO4 gives a gaseous product (B) of empirical formula (CH2)n. Compound (B) decolourises bromine water and alk. KMnO4. (B) also reacts with one mole of H2 in presence of Ni. What are (A) and (B)?

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An organic liquid with sweet smell and b.pt 78°C contains C, H and O. On heating with conc. H2SO4 gives a gaseous product (B) of empirical formula (CH2)n. Compound (B) decolourises bromine water and alk. KMnO4. (B) also reacts with one mole of H2 in presence of Ni. What are (A) and (B)?

Anonymous User tag : Chemistry Alcohols Phenols and Ethers 15 Mar, 2020 0 Answer 51 views

Although both polymers are prepared by free radical processes, poly (vinyl chloride) is amorphous and poly (vinylidene chloride) (saran) is highly crystallilne. How do you account for the different? (vinylidene chloride is 1,1- dichloroethene).

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Although both polymers are prepared by free radical processes, poly (vinyl chloride) is amorphous and poly (vinylidene chloride) (saran) is highly crystallilne. How do you account for the different? (vinylidene chloride is 1,1- dichloroethene).

Anonymous User tag : Chemistry Polymers 15 Mar, 2020 1 Answer 53 views

In a fcc arrangement of A & B atoms, where A atoms are at the Corners of the unit cell, B atoms at the face centers, two atoms are missing from two corners in each unit cell, then the simplest formula of the compound is

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In a fcc arrangement of A & B atoms, where A atoms are at the Corners of the unit cell, B atoms at the face centers, two atoms are missing from two corners in each unit cell, then the simplest formula of the compound is

Anonymous User tag : Chemistry Solid State 14 Mar, 2020 1 Answer 55 views

In a face centred lattice with all the positions occupied by A atoms the body centred octahedral hole in it is occupied by an atom B of an appropriate size for such a crystal, calculate the void space per unit volume of unit cell. Also predict the formula of the compound?

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In a face centred lattice with all the positions occupied by A atoms the body centred octahedral hole in it is occupied by an atom B of an appropriate size for such a crystal, calculate the void space per unit volume of unit cell. Also predict the formula of the compound?

Anonymous User tag : Chemistry Solid State 14 Mar, 2020 1 Answer 57 views

A tube of uniform cross sectional area 1 cm2 is closed at one end with semi permiable membrane. A solution having 5 gm glucose per 100 ml is placed inside the tube and dipped in pure water at 27°C. When the equilibrium is established, what will be the osmotic pressure, height developed in vertical column. Also calculate molality and molarity of the solution. Density of glucose solution is 1 gm/ml

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A tube of uniform cross sectional area 1 cm2 is closed at one end with semi permiable membrane. A solution having 5 gm glucose per 100 ml is placed inside the tube and dipped in pure water at 27°C. When the equilibrium is established, what will be the osmotic pressure, height developed in vertical column. Also calculate molality and molarity of the solution. Density of glucose solution is 1 gm/ml

Anonymous User tag : Chemistry Solutions 13 Mar, 2020 1 Answer 60 views

Dry air was passed successively through a solution of 5 g of a solute in 180 g of water and then through pure water. The loss in weight of solution was 2.50 g and that of pure solvent 0.04 g. The molecular weight of the solute is:

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Dry air was passed successively through a solution of 5 g of a solute in 180 g of water and then through pure water. The loss in weight of solution was 2.50 g and that of pure solvent 0.04 g. The molecular weight of the solute is:

Anonymous User tag : Chemistry Solutions 13 Mar, 2020 1 Answer 53 views

Solute A is a ternary electrolyte and solute B is non-electrolyte. If 0.1 M solution of solute B produces an osmotic pressure of 2P, then 0.05 M solution of A at the same temperature will produce on osmotic pressure equal to

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Solute A is a ternary electrolyte and solute B is non-electrolyte. If 0.1 M solution of solute B produces an osmotic pressure of 2P, then 0.05 M solution of A at the same temperature will produce on osmotic pressure equal to

Anonymous User tag : Chemistry Solutions 13 Mar, 2020 1 Answer 53 views

The vapour pressure of benzene at 80°C is lowered by 10 mm by dissolving 2g of a non-volatile substance in 78g of benzene. The vapour pressure of pure benzene at 80°C is 750 mm. The molecular weight of the substance will be:

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The vapour pressure of benzene at 80°C is lowered by 10 mm by dissolving 2g of a non-volatile substance in 78g of benzene. The vapour pressure of pure benzene at 80°C is 750 mm. The molecular weight of the substance will be:

Anonymous User tag : Chemistry Solutions 13 Mar, 2020 1 Answer 57 views

The vapour pressures of ethanol and methanol are 42.0 mm and 88.5 mm Hg respectively. An ideal solution is formed at the same temperature by mixing 46.0 g of ethanol with 16.0 g of methanol. The mole fraction of methanol in the vapour is:

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The vapour pressures of ethanol and methanol are 42.0 mm and 88.5 mm Hg respectively. An ideal solution is formed at the same temperature by mixing 46.0 g of ethanol with 16.0 g of methanol. The mole fraction of methanol in the vapour is:

Anonymous User tag : Chemistry Solutions 13 Mar, 2020 1 Answer 53 views

In a reaction at equilibrium ‘X’ moles of the reactant A decomposes to give 1 mole each of C and D. If the fraction of A decomposed at equilibrium is independent of initial concentration of A then the value ‘X’ is

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In a reaction at equilibrium ‘X’ moles of the reactant A decomposes to give 1 mole each of C and D. If the fraction of A decomposed at equilibrium is independent of initial concentration of A then the value ‘X’ is

Anonymous User tag : Chemistry Equilibrium 12 Mar, 2020 1 Answer 53 views

The partial pressure of CH3OH (g), CO(g) and H2(g) in equilibrium mixture for the reaction CO(g) + 2H2(g) ----> CH3OH(g) are 2.0, 1.0, and 0.1 atm respectively at 427°C. The value of Kp for decomposition of CH3OH to CO and H2 is

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The partial pressure of CH3OH (g), CO(g) and H2(g) in equilibrium mixture for the reaction

CO(g) + 2H2(g) ----> CH3OH(g)

are 2.0, 1.0, and 0.1 atm respectively at 427°C. The value of Kp for decomposition of CH3OH to CO and H2 is

Anonymous User tag : Chemistry Equilibrium 12 Mar, 2020 1 Answer 53 views

In the system, LaCl3(s) + H2O (g)+heat  ------------>.   LaClO(s)+2HCl (g), equilibrium is established. More water vapour is added to reestablish the equilibrium. The pressure of water vapour is doubled. The factor by which pressure of HCl is changed is  

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In the system, LaCl3(s) + H2O (g)+heat  ------------>.   LaClO(s)+2HCl (g), equilibrium is established. More water vapour is added to reestablish the equilibrium. The pressure of water vapour is doubled. The factor by which pressure of HCl is changed is

 

Anonymous User tag : Chemistry Equilibrium 12 Mar, 2020 1 Answer 57 views

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 69 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 163 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 59 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 70 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 71 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 181 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 561 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 83 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 73 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 2150 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 64 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 114 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 161 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 190 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 3590 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 2345 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 85 views