Select Board & Class
Why is the dipole moment of NH3 greater then that of NF3 ??
chemistry chapter wise marks(cbse board)
which of the following is an example of metallic crystal solid?
(a) C ( b) Si (c) W (d) AgCl
what is F centre?
If Nacl is doped with 10-3 mole % of Srcl2 , what is the concentration of cation vacancies?
A unit cell of ccp or fcc lattice is divided into eight small cubes. Then, each small cube has 4 atoms at alternate corners. When these are joined to each other, a regular tetrahedron is formed.
Cnt undrstnd it.. That how tetrahedron is formed on joining them???
equivalent weight of silver nitrate
why are frenkel defects not found in pure alkali halides?
In numericals,we use Z values-1 for sc,2 for bcc and 4 for fcc, but in this given question:
Potassium crystallises in a bcc lattice,hence the coordination number of potassium metal is 8. Why is it so?
best reference books for class12 science[cbse]
Q. Why old glass objects appear slightly milky instead of being transparent?
What is Schottky and Frenkel defects?
what is the full form of hcp and ccp?
why does AgBr show both frenkel n schottky defect? and why does ONLY AgBr show both d defects?
The number of atoms in 100g of FCC crystal with density = 10g/cm3 and cell edge equal to 200 pm is equal to _____?
what is cryoscopic constant?
If the radius of the tetrahedral void is r and radius of the atoms in close packing is R, derive the relation between r and R?
A compound formed by elements X and Y crystallizes in the cubic structure where Y atoms are at the corners of the cube and X atoms are at the alteranate faces. What is the formula of the compound?
Which point defects lowers the density of a crystal?
sodium metal crystallizes in BCC structure . Its unit cell edge length is 420pm calculate density. (Atomic mass is 23u and NA= 6.022 x 1023 mol -1.)
calculate the distance between Na+ and Cl- ions in NaCl crystal if its density is 2.165 gcm-3 (molar mass of NaCl = 58.5gmol-1 NA = 6.02 x 10 23 mol-1)
what is pseudo solid
THE density of 3M aqueous solution of sodium thiosulphate is 1.25g/mL. Calculate 1. mole fraction of sodium thiosulphate
2. molalities of Na+ and S2O32-
in a face centered cubic lattice, a unit cell is shared equally by how many unit cells?
(The queston is from relative molecular mass and mole)
A solution of glycol containing 1.82g per litre has an osmotic pressure of 51.8cm of mercury at 10°C .What is the molecular weight of glycol?
(ans is 62.04)
what is the coordination number in hcp and ccp arrangement????
what r the differences between tetrahedral and octahedral void?
wwhich one of the following will have a low heat of fusion?(A)a covalent solid
(B)an ionic solid
(C)a mettallic solid
(D)a molecular solid
atoms of the element B form hcp lattice and those of element A occupy 2by3rd part of tetrahydral voids what is the formula of the compound formed by the element A and B
two differences between tetrahedral void and octahedral void?
how many second neighbours are in hcp and fcc?
Why does KCl turn violet on heating in the potassium vapor?
Please reply to this question as soon as possible.It's very important for me!!!!!!.
25.3 g of sodium carbonate is dissolved in enough water to make 250 mL of solution.If sodium carbonate dissociates completely,molar concentration of sodium ion,Na+ and carbonate ions,CO3^2- are respectively.......
1. what r true solids and pseudo solids?
2. why crystalline solids are true solids and amorphous solids r pseudo solids?
difference between schottky defect and frenkel defect
why CN of atoms is high in schottky defect
Ques.The density of copper metal is 8.95 g cm3. If the radius of copper atom is 127.8 pm, is the copper unit cell a simple cubic, a body-centred cubic or a face centred cubic structure? (Given: At. Mass of Cu = 63.54 g mol1and NA= 6.02 × 1023mol1)
a compound forms hexagonal close packed structure. what is the total number of voids in 0.5mol of it? how many of these are tetrahedral voids?
What is the difference between crystal lattice and unit cell?
What is a Chalk crystalline or amporphous? and why?
Specific volume of cylindrical virus particle is 6.02 * 10-2 cc/gm whose radius and length are 7angstrom and 10angstrom respectively.If NA=6.02 *10^23 find molecular weight of virus???
Sodium crystallizes in a BCC unit cell. Calculate the approximate no. of unit cell in 9.2 gm of sodium?
what is the distance bet'n 2 tetrahedral voids in ccp structure ???????
ans is
1. a/root 2
2.a/2
3.root3*a/2
4.all above
answer is 4
Write the I.U.P.A.C name:-
i) Fe4 [Fe(CN)6]3
ii) Na3 [Fe(C2O4)3]
iii) K3[Fe(C2O4)3]
iv) [Cr(en)3]Cl3
v) [CoBr(H2o)(NH3)](NO3)2
why argon is considered as a non polar molecular solid?
which stoichiometric defect in crystals increases the density of a solid?
What are non-polar molecular solids?
whta type of crystal defect is produced when NaCl is doped with MgCl2?
pls explain metal excess and metal deficiency defect again...or by a video...ASAP
valency of silver nitrate
why frenkel defect does not change the density of agcl crystals???
what is the difference between isomorphism and polymorphism pls explain with some examples too..
Dipole moment of p-dichlorobenzene is zero, but for p-dihydroxybenzene dipole moment is not zero.
can u store copper sulphate solution in zinc pot?
conductivity of silicon increases on doping it with phosphorus reason
Vapours of an organic compound when passed over hot reduced cu at 573k give acetone. Identify the compund.
an element has bcc with a cell edge of 288pm the density of the element is 7.2 gm/cm^3. how many atoms are present in 208gm of the element?
WHT IS OCTAHEDRAL VOID AND TETRAHEDRAL VOIDS
what is the coordination number of Co in [Co(NO2)2 (en)2]+
Q1)What is the coordination no. of each type of ions in a rock-salt type crystal structure? how?
Potassium crystallizes in a body centred cubic lattice.calculate the approximate number of unit cells in 1g of potassium.(Atomic mass of the potassium is 39u)
The pyknometric density of sodium chloride crystal is 2.165 x 103 kg m-3 while its X-ray density is 2.178 x 103 kg m-3. The fraction of the unoccupied sites in sodium chloride crytal is?
E.g: 9876543210, 01112345678
We will give you a call shortly, Thank You
Office hours: 9:00 am to 9:00 pm IST (7 days a week)
Syllabus
Why is the dipole moment of NH3 greater then that of NF3 ??
(1) 6.023 x 1023 (2) 6.023 x 1018
(3) 6.023 x 1016 (4) 1.2046 x 1017
chemistry chapter wise marks(cbse board)
which of the following is an example of metallic crystal solid?
(a) C ( b) Si (c) W (d) AgCl
what is F centre?
If Nacl is doped with 10-3 mole % of Srcl2 , what is the concentration of cation vacancies?
A unit cell of ccp or fcc lattice is divided into eight small cubes. Then, each small cube has 4 atoms at alternate corners. When these are joined to each other, a regular tetrahedron is formed.
Cnt undrstnd it.. That how tetrahedron is formed on joining them???
equivalent weight of silver nitrate
why are frenkel defects not found in pure alkali halides?
In numericals,we use Z values-1 for sc,2 for bcc and 4 for fcc, but in this given question:
Potassium crystallises in a bcc lattice,hence the coordination number of potassium metal is 8. Why is it so?
best reference books for class12 science[cbse]
Q. Why old glass objects appear slightly milky instead of being transparent?
What is Schottky and Frenkel defects?
what is the full form of hcp and ccp?
why does AgBr show both frenkel n schottky defect? and why does ONLY AgBr show both d defects?
The number of atoms in 100g of FCC crystal with density = 10g/cm3 and cell edge equal to 200 pm is equal to _____?
P4, S8, SiC, Al2O3, He, Al2Cl6
what is cryoscopic constant?
If the radius of the tetrahedral void is r and radius of the atoms in close packing is R, derive the relation between r and R?
A compound formed by elements X and Y crystallizes in the cubic structure where Y atoms are at the corners of the cube and X atoms are at the alteranate faces. What is the formula of the compound?
a)2
b)4
c)6
d)8
Which point defects lowers the density of a crystal?
sodium metal crystallizes in BCC structure . Its unit cell edge length is 420pm calculate density. (Atomic mass is 23u and NA= 6.022 x 1023 mol -1.)
calculate the distance between Na+ and Cl- ions in NaCl crystal if its density is 2.165 gcm-3 (molar mass of NaCl = 58.5gmol-1 NA = 6.02 x 10 23 mol-1)
what is pseudo solid
THE density of 3M aqueous solution of sodium thiosulphate is 1.25g/mL. Calculate 1. mole fraction of sodium thiosulphate
2. molalities of Na+ and S2O32-
in a face centered cubic lattice, a unit cell is shared equally by how many unit cells?
(The queston is from relative molecular mass and mole)
A solution of glycol containing 1.82g per litre has an osmotic pressure of 51.8cm of mercury at 10°C .What is the molecular weight of glycol?
(ans is 62.04)
what is the coordination number in hcp and ccp arrangement????
(1) 2X ml (2) X ml (3) ml (4) 3X ml
what r the differences between tetrahedral and octahedral void?
wwhich one of the following will have a low heat of fusion?
(A)a covalent solid
(B)an ionic solid
(C)a mettallic solid
(D)a molecular solid
atoms of the element B form hcp lattice and those of element A occupy 2by3rd part of tetrahydral voids what is the formula of the compound formed by the element A and B
two differences between tetrahedral void and octahedral void?
how many second neighbours are in hcp and fcc?
Why does KCl turn violet on heating in the potassium vapor?
Please reply to this question as soon as possible.It's very important for me!!!!!!.
1) how temperature remains constant
By heat liberation ??
"Cooling curve : Amorphous solids show smooth cooling curve while crystalline solids show two
breaks in cooling curve. In the case of crystalline solids two breaks points 'a' and 'b' are appear. These
points indicate the beginning and the end of the process of crystallization. In this time interval temperature
remains constant. This is due to the fact that during crystallisation process energy is liberated which
compensates for the loss of heat thus the temperature remains constant."
25.3 g of sodium carbonate is dissolved in enough water to make 250 mL of solution.If sodium carbonate dissociates completely,molar concentration of sodium ion,Na+ and carbonate ions,CO3^2- are respectively.......
1. what r true solids and pseudo solids?
2. why crystalline solids are true solids and amorphous solids r pseudo solids?
28 u nitrogen gas .
28 g N2 gas at STP.
difference between schottky defect and frenkel defect
why CN of atoms is high in schottky defect
Ques.The density of copper metal is 8.95 g cm3. If the radius of copper atom is 127.8 pm, is the copper unit cell a simple cubic, a body-centred cubic or a face centred cubic structure? (Given: At. Mass of Cu = 63.54 g mol1and NA= 6.02 × 1023mol1)
can you please explain how it is fcc?d=M.z a3.NAOn substituting we get,8.95=z.63.54 6.022X1023X(1.27X10-8)3z=0.17.please help me out! where did i go wrong?a compound forms hexagonal close packed structure. what is the total number of voids in 0.5mol of it? how many of these are tetrahedral voids?
What is the difference between crystal lattice and unit cell?
What is a Chalk crystalline or amporphous? and why?
Specific volume of cylindrical virus particle is 6.02 * 10-2 cc/gm whose radius and length are 7angstrom and 10angstrom respectively.If NA=6.02 *10^23 find molecular weight of virus???
Sodium crystallizes in a BCC unit cell. Calculate the approximate no. of unit cell in 9.2 gm of sodium?
what is the distance bet'n 2 tetrahedral voids in ccp structure ???????
ans is
1. a/root 2
2.a/2
3.root3*a/2
4.all above
answer is 4
Q). When heated above 916C iron changes from bcc crystalline form to fcc form without any changes in the radius of atom. The ratio of density of the crystal before and after heating is
(1) 1.069
(2) 0.918
(3) 0.725
(4) 1.231
Write the I.U.P.A.C name:-
i) Fe4 [Fe(CN)6]3
ii) Na3 [Fe(C2O4)3]
iii) K3[Fe(C2O4)3]
iv) [Cr(en)3]Cl3
v) [CoBr(H2o)(NH3)](NO3)2
why argon is considered as a non polar molecular solid?
which stoichiometric defect in crystals increases the density of a solid?
What are non-polar molecular solids?
(i) Si O2 (ii) Mg O (iii) SO2(s) (iv) Cr O2
whta type of crystal defect is produced when NaCl is doped with MgCl2?
pls explain metal excess and metal deficiency defect again...or by a video...ASAP
valency of silver nitrate
why frenkel defect does not change the density of agcl crystals???
what is the difference between isomorphism and polymorphism pls explain with some examples too..
Dipole moment of p-dichlorobenzene is zero, but for p-dihydroxybenzene dipole moment is not zero.
can u store copper sulphate solution in zinc pot?
conductivity of silicon increases on doping it with phosphorus reason
Vapours of an organic compound when passed over hot reduced cu at 573k give acetone. Identify the compund.
an element has bcc with a cell edge of 288pm the density of the element is 7.2 gm/cm^3. how many atoms are present in 208gm of the element?
2 -7 xl03 kgm-
3 . Calculate edge length of the unit cell. Given atomic mass of
aluminium equal to 27 ?0amu.
WHT IS OCTAHEDRAL VOID AND TETRAHEDRAL VOIDS
what is the coordination number of Co in [Co(NO2)2 (en)2]+
Q1)What is the coordination no. of each type of ions in a rock-salt type crystal structure? how?
Potassium crystallizes in a body centred cubic lattice.calculate the approximate number of unit cells in 1g of potassium.(Atomic mass of the potassium is 39u)
The pyknometric density of sodium chloride crystal is 2.165 x 103 kg m-3 while its X-ray density is 2.178 x 103 kg m-3. The fraction of the unoccupied sites in sodium chloride crytal is?