Recent questions in Chemistry

An aqueous solution of 2% non-volatile solute exerts a pressure of 1.004 bar at the normal boiling point of the solvent. What is the molar mass of the solute?

asked Aug 5, 2014 by sreemathi.v

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What is meant by positive and negative deviations from Raoult's law and how is the sign of $\Delta_{mix}H$ related to positive and negative deviations from Raoult's law?

asked Aug 5, 2014 by sreemathi.v

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The partial pressure of ethane over a solution containing $6.56 × 10^{–3}$ g of ethane is 1 bar. If the solution contains $5.00 ×\times 10^{–2}$ g of ethane, then what shall be the partial pressure of the gas?

asked Aug 4, 2014 by sreemathi.v

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State Henry’s law and mention some important applications?

asked Aug 4, 2014 by sreemathi.v

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Why do gases always tend to be less soluble in liquids as the temperature is raised?

asked Aug 4, 2014 by sreemathi.v

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What role does the molecular interaction play in a solution of alcohol and water?

asked Aug 4, 2014 by sreemathi.v

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A sample of drinking water was found to be severely contaminated with chloroform $(CHCl_3$) supposed to be a carcinogen. The level of contamination was 15 ppm (by mass): determine the molality of chloroform in the water sample.

asked Aug 4, 2014 by sreemathi.v

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A sample of drinking water was found to be severely contaminated with chloroform $(CHCl_3$) supposed to be a carcinogen. The level of contamination was 15 ppm (by mass): express this in percent by mass

asked Aug 4, 2014 by sreemathi.v

1 answer

An antifreeze solution is prepared from 222.6 g of ethylene glycol $(C_2H_6O_2$) and 200 g of water. Calculate the molality of the solution. If the density of the solution is $1.072 g mL^{–1}$, then what shall be the molarity of the solution?

asked Aug 4, 2014 by sreemathi.v

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A solution is obtained by mixing 300 g of 25% solution and 400 g of 40% solution by mass. Calculate the mass percentage of the resulting solution.

asked Aug 4, 2014 by sreemathi.v

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How many mL of 0.1 M HCl are required to react completely with 1 g mixture of $Na_2CO_3$ and $NaHCO_3$ containing equimolar amounts of both?

asked Aug 4, 2014 by sreemathi.v

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A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is $1.2 g mL^{–1}$, then what shall be the molarity of the solution?

asked Aug 4, 2014 by sreemathi.v

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Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in aqueous solution. What should be the molarity of such a sample of the acid if the density of the solution is $1.504 g mL^{–1}$?

asked Aug 4, 2014 by sreemathi.v

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Define the following term : Mass percentage

asked Aug 4, 2014 by sreemathi.v

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Define the following term : Molarity

asked Aug 4, 2014 by sreemathi.v

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Define the following term : Molality

asked Aug 4, 2014 by sreemathi.v

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Define the following term : Mole fraction

asked Aug 4, 2014 by sreemathi.v

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Give an example of a solid solution in which the solute is a gas.

asked Aug 4, 2014 by sreemathi.v

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Define the term solution. How many types of solutions are formed? Write briefly about each type with an example.

asked Aug 4, 2014 by sreemathi.v

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How many unit cells are present in a cube-shaped ideal crystal of NaCl of mass 1.00g.

asked Aug 4, 2014 by sreemathi.v

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A metallic element has a cubic lattice .Each edge of the unit cell is $2A^{\large\circ}$.The density of the metal is $2.5gcm^{-3}$.The unit cells in 200g of the metal are ?

asked Aug 4, 2014 by sreemathi.v

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At room temperature ,sodium crystallises in a body-centred cubic lattice with $a=4.24A^{\large\circ}$.The theoretical density of sodium (At.wt of Na=23) is ?

asked Aug 4, 2014 by sreemathi.v

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Potassium has a bcc structure with nearest neighbour distance $4.52A^{\large\circ}$.Its atomic weight is 39.Calculate its density.

asked Aug 4, 2014 by sreemathi.v

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An element crystallises in a structure having fcc unit cell with edge length of 200pm.Calculate its density .If 200g of this element contains $24\times 10^{23}$ atoms.

asked Aug 4, 2014 by sreemathi.v

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An element crystallizes in the simple cubic structure.Its density is $8gcm^{-3}$ and its 200g contains $24\times 10^{23}$ atoms.Calculate the edge length.

asked Aug 4, 2014 by sreemathi.v

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A metal (atomic mass =50) has a body-centred cubic lattice.The density of the metal is $5.91gcm^{-3}$.Find out the volume of the unit cell.$[N_A=6.023\times 10^{23}]$

asked Aug 4, 2014 by sreemathi.v

1 answer

An element (atomic mass =60) having face-centred cubic unit cell has a density of $6.23gcm^{-3}$.What is edge length of unit cell ?

asked Aug 4, 2014 by sreemathi.v

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Sodium crystallises in the cubic lattice and the edge of the unit cell is 430pm.Calculate the number of atoms in a unit cell.

asked Aug 4, 2014 by sreemathi.v

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An element has a body centred cubic structure with a cell edge of 288 pm.The density of the element is $7.2gcm^{-3}$.calculate the number of atoms present in 280g of the element.

asked Aug 4, 2014 by sreemathi.v

1 answer

An element E crystallizes in body-centred cubic structure.If the edge centre of the cell is $1.469\times 10^{-10}$m and the density is $19.3gcm^{-3}$.Calculate the atomic mass of this element.Also calculate the radius of an atom of this element.

asked Aug 4, 2014 by sreemathi.v

1 answer

In an ionic compound the anion $(N^-)$ from cubic close type of packing,while the cation $(M^+)$ ions occupy one third of the tetrahedral voids.Deduce the empirical formula of the compound and the coordination number of $(M^+)$ ions.

asked Aug 4, 2014 by sreemathi.v

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Analysis shows that a metal oxide has the empirical formula $M_{0.96}O_{1.00}$.Calculate the percentage of $M^{2+}$ and $M^{3+}$ ions in the crystal?

asked Aug 4, 2014 by sreemathi.v

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The pycnometric density of sodium chloride crystal is $2.165\times 10^3kg m^{-3}$ while its X-ray density is $2.178\times 10^3kg m^{-3}$.The fraction of the unoccupied sites in sodium chloride crystal is

asked Aug 1, 2014 by sreemathi.v

1 answer

In a cubic lattice each edge of the unit cell is 400pm.Atomic weight of the element is 60 and its density is $6.25g/c.c$.Avogadro number =$6.023\times 10^{23}$.What will be the crystal lattice.

asked Aug 1, 2014 by sreemathi.v

1 answer

You are given marbles of diameter 10mm.They are to be placed such their centres are lying in a square bond by four lines each of length 40mm.What will be the arrangement of marbles in a plane so that maximum number of marbles can be placed inside the area?Derive the expression for the number of molecules per unit area.

asked Aug 1, 2014 by sreemathi.v

1 answer

The first order reflection of a beam of X-rays of wavelength $1.54A^{\large\circ}$ from the (1 0 0) plane of a crystal of the simple cubic type occurs at an angle of $11.29^{\large\circ}$.Calculate the length of the unit cell.

asked Aug 1, 2014 by sreemathi.v

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A sample of wustite $Fe_xO$ contains one Fe(III) for every three Fe(II).Calculate the value of $x$.

asked Aug 1, 2014 by sreemathi.v

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The edge length of a cubic unit cell of metallic calcium is 556 pm.If the density of calcium is $1.54gcm^{-3}$ and its molar mass is $40.08gmol^{-3}$.Calculate the radius of calcium atom.

asked Aug 1, 2014 by sreemathi.v

1 answer

An element having atomic mass 60 has face-centered cubic unit cells.The edge length of the unit cell is 400pm.Find the density of the element.

asked Aug 1, 2014 by sreemathi.v

1 answer

Calcium crystallises in a face-centred cubic unit cell with a=0.556nm.Calculate the density if it contained 0.1% Schottky defects.

asked Aug 1, 2014 by sreemathi.v

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Calcium crystallises in a face-centred cubic unit cell with a=0.556nm.Calculate the density if it contained 0.1% Frenkel defects.

asked Aug 1, 2014 by sreemathi.v

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If NaCl is doped with $10^{-3}$ mole percentage of $SrCl_2$,what is the concentration of cation vacancy?

asked Aug 1, 2014 by sreemathi.v

1 answer

In a crystalline solid,having formula $AB_2O_4$,oxide ions are arranged in cubic close packed lattice while cations A are present in tetrahedral voids and cations B are present in octahedral voids.What percentage of the tetrahedral voids is occupied by A and B?

asked Aug 1, 2014 by sreemathi.v

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Copper has the fcc crystal structure.Assuming an atomic radius of 130pm for copper atom (Cu = 63.54).Find the density of Cu.

asked Aug 1, 2014 by sreemathi.v

1 answer

Copper has the fcc crystal structure.Assuming an atomic radius of 130pm for copper atom (Cu = 63.54).How many atoms belong to the unit cell?

asked Aug 1, 2014 by sreemathi.v

1 answer

Copper has the fcc crystal structure.Assuming an atomic radius of 130pm for copper atom (Cu = 63.54).What is the volume of the unit cell?

asked Aug 1, 2014 by sreemathi.v

1 answer

Copper has the fcc crystal structure.Assuming an atomic radius of 130pm for copper atom (Cu = 63.54).What is the length of unit cell of Cu?

asked Aug 1, 2014 by sreemathi.v

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X-ray diffraction studies show that copper crystallizes in an fcc unit cell with cell edge of $3.608\times 10^{-8}$cm.In a separate environment,copper is determined to have a density of $8.92g/cm^3$,calculate the atomic (molar) mass of the copper.

asked Aug 1, 2014 by sreemathi.v

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Prove that the void space percentage in zinc blende structure is 25%

asked Aug 1, 2014 by sreemathi.v

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KCl crystallizes in the same type of lattice as does $NaCl$.Given that,$\large\frac{r_{Na^+}}{r_{Cl^-}}=$$0.5,\large\frac{r_{Na^+}}{r_{K^+}}=$$0.7$.Calculate the ratio of the side of the unit cell for KCl to that for NaCl and the ratio of density of NaCl to that for KCl.

asked Aug 1, 2014 by sreemathi.v

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