Recent questions tagged medium

The length of the unit cell edge of a body-centred cubic metal crystal is 352pm.Calculate the radius of an atom of the metal.

asked Aug 1, 2014 by sreemathi.v

1 answer

By X-ray diffraction it is found that nickel crystals are face-centred cubic.The edge of the unit cell is $3.52A^{\large\circ}$.The atomic mass of nickel is $58.7$ and its density is $8.94g/cm^3$.Calculate Avogadro's number from the data.

asked Aug 1, 2014 by sreemathi.v

1 answer

Iron crystallizes in a bcc system with a lattice parameter of $2.861A^{\large\circ}$.Calculate the density of iron in the bcc system.(Given : Atomic weight of $Fe=56,N=6.023\times 10^{23}mol^{-1}$)

asked Aug 1, 2014 by sreemathi.v

1 answer

A metal of density $7.5\times 10^3kgm^{-3}$ has an fcc crystal structure with lattice parameter $a=400$pm.Calculate the number of unit cells present in 0.015kg of the metal

asked Aug 1, 2014 by sreemathi.v

1 answer

Which of the following salts is not formed when $CuSO_4.5H_2O$ is heated ?

asked Jul 31, 2014 by thanvigandhi_1

1 answer

Which of the following alloys of copper contains nickel ?

asked Jul 31, 2014 by thanvigandhi_1

1 answer

Which of the following alloys of copper does not contain tin ?

asked Jul 31, 2014 by thanvigandhi_1

1 answer

Which of the following alloys of copper does not contain zinc ?

asked Jul 31, 2014 by thanvigandhi_1

1 answer

Ozone reacts with

asked Jul 31, 2014 by thanvigandhi_1

1 answer

Aqua regia reacts with

asked Jul 31, 2014 by thanvigandhi_1

1 answer

Dilute $H_2SO_4$ and dilute $HCl$ in the presence of air react with

asked Jul 31, 2014 by thanvigandhi_1

1 answer

Hot concentrated $H_2SO_4$ reacts with

asked Jul 31, 2014 by thanvigandhi_1

1 answer

The reaction of concentrated $\text{HNO}_3$ with $\text{Cu}$ or $\text{Ag}$ liberates

asked Jul 31, 2014 by thanvigandhi_1

1 answer

The reaction of dilute $\text{HNO}_3$ with $\text{Cu}$ or $\text{Ag}$ libertaes the gas

asked Jul 31, 2014 by thanvigandhi_1

1 answer

Which of the following statements is not correct ?

asked Jul 31, 2014 by thanvigandhi_1

1 answer

Calculate the angle at which second-order reflection will occur in an X-ray spectrometer when X-rays of 0.154nm are diffracted by the atoms of a crystal having distance b/w two planes at 404 pm

asked Jul 31, 2014 by sreemathi.v

1 answer

A sample of crystalline solid scatters a beam of X-rays of wavelength 70.93pm at an angle $2\theta$ of $14.66^{\large\circ}$.If this is a second order reflection (n=2),calculate the distance between the parallel planes of atoms from which the scattered beam appears to have been reflected.

asked Jul 31, 2014 by sreemathi.v

1 answer

In terms of band theory, what is the difference between a conductor and a semiconductor

asked Jul 30, 2014 by sreemathi.v

1 answer

In terms of band theory, what is the difference between a conductor and an insulator

asked Jul 30, 2014 by sreemathi.v

1 answer

Ferric oxide crystallises in a hexagonal close-packed array of oxide ions with two out of every three octahedral holes occupied by ferric ions. Derive the formula of the ferric oxide.

asked Jul 30, 2014 by sreemathi.v

1 answer

Calculate the efficiency of packing in case of a metal crystals for : face-centered cubic (with the assumptions that atoms are touching each other)

asked Jul 30, 2014 by sreemathi.v

1 answer

Calculate the efficiency of packing in case of a metal crystals for : body-centered cubic

asked Jul 30, 2014 by sreemathi.v

1 answer

Calculate the efficiency of packing in case of a metal crystals for : simple cubic

asked Jul 30, 2014 by sreemathi.v

1 answer

Explain : Ionic solids are hard and brittle

asked Jul 30, 2014 by sreemathi.v

1 answer

Explain : The basis of similarities and differences between metallic and ionic crystals.

asked Jul 30, 2014 by sreemathi.v

1 answer

'Stability of a crystal is reflected in the magnitude of its melting points'. Comment. Collect melting points of solid water, ethyl alcohol, diethyl ether and methane from a data book. What can you say about the intermolecular forces between these molecules?

asked Jul 29, 2014 by sreemathi.v

1 answer

How can you determine the atomic mass of an unknown metal if you know its density and the dimension of its unit cell? Explain.

asked Jul 29, 2014 by sreemathi.v

1 answer

Classify the following solid as ionic, metallic, molecular, network (covalent) or amorphous.Rb

asked Jul 29, 2014 by sreemathi.v

1 answer

A cylinder contains $0.03\; m^3$ of Argon gas at a temperature of $25^\circ C$ and a pressure of $1.2\; MPa$. Find the internal energy of the gas.

asked Jul 29, 2014 by balaji.thirumalai

1 answer

What makes a glass different from a solid such as quartz? Under what conditions could quartz be converted into glass?

asked Jul 29, 2014 by sreemathi.v

1 answer

In the preparation of compounds of Xe, Bartlett had taken $O_2^{+} Pt F_6^{-}$ as a base compound. This is because:

asked Jul 29, 2014 by balaji.thirumalai

1 answer

The structure of $ClF_3$ is

asked Jul 29, 2014 by sreemathi.v

1 answer

The hybridization $sp^3d^3$ leads to

asked Jul 29, 2014 by sreemathi.v

1 answer

Which of the following is not a pseudohalogen ?

asked Jul 29, 2014 by sreemathi.v

1 answer

The hybridization of I in $ICl^-_4$ is

asked Jul 29, 2014 by sreemathi.v

1 answer

The hybridization of I in $ICl^-_2$ is

asked Jul 29, 2014 by sreemathi.v

1 answer

Which of the following orders regarding the acid character of hydrogen halides in the aqueous medium is correct?

asked Jul 28, 2014 by sreemathi.v

1 answer

Which of the following reactions regarding the preparation of hydrogen halide is not correct?

asked Jul 28, 2014 by sreemathi.v

1 answer

Which of the following reactions would not proceed to right hand side?

asked Jul 28, 2014 by sreemathi.v

1 answer

Which of the following equations is not shown by the appropriate halogen ?

asked Jul 28, 2014 by sreemathi.v

1 answer

Which of the following statements regarding aluminium is not correct ?

asked Jul 28, 2014 by thanvigandhi_1

1 answer

If $\varepsilon_{C-C}=348kJmol^{-1},\varepsilon_{C-H}=412kJ mol^{-1}$ and $\varepsilon_{H-H}=436KJ mol^{-1}$,the pauling electronegativity of C is about (Given : electronegativity of H =2.1)

asked Jul 28, 2014 by sreemathi.v

1 answer

When XeF$_4$ reacts with water, which of the following are possible product(s) that can be formed? Xe, HF, XeO$_3$, XeOF$_3$, XeO$_4$, O$_3$.

asked Jul 27, 2014 by balaji.thirumalai

1 answer

The structure of XeO$_3$ is

asked Jul 27, 2014 by balaji.thirumalai

1 answer

Which of the following regarding Helium is incorrect?

asked Jul 27, 2014 by balaji.thirumalai

1 answer

In the reaction $H_3BO_3$$ _{\overrightarrow{375k}} A$$ _{\overrightarrow{475k}} B$$ _{\overrightarrow{red\: heat}} C$ The compounds A, B and C respectively are

asked Jul 27, 2014 by thanvigandhi_1

1 answer

Heating of $Al_2(SO_4)_3$ gives

asked Jul 26, 2014 by thanvigandhi_1

1 answer

For the reaction $A+B \rightarrow C+D$, calculate the value of k for this reaction based on the following data collected in three different experiments:

asked Jul 25, 2014 by balaji.thirumalai

1 answer

Calculate the value of k for this reaction based on the following data collected in three different experiments:

asked Jul 25, 2014 by balaji.thirumalai

1 answer

Which of the following statements regarding the structure aluminium chloride is correct ?

asked Jul 25, 2014 by thanvigandhi_1

1 answer

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