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Why is the dipole moment of NH3 greater then that of NF3 ??
chemistry chapter wise marks(cbse board)
what is F centre?
the most closely packed among the following crystal lattices is(A)simple cubic close packing
(B)body centred cubic arrangement
(C)face centred cubic arrangement
(D)both fcc and bcc
If Nacl is doped with 10-3 mole % of Srcl2 , what is the concentration of cation vacancies?
equivalent weight of silver nitrate
why are frenkel defects not found in pure alkali halides?
which of the following is an example of metallic crystal solid?
(a) C ( b) Si (c) W (d) AgCl
best reference books for class12 science[cbse]
1. what r true solids and pseudo solids?
2. why crystalline solids are true solids and amorphous solids r pseudo solids?
Q. Why old glass objects appear slightly milky instead of being transparent?
What is Schottky and Frenkel defects?
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?
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
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)
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?
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?
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?
difference between molten and aqueous???
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.......
how many second neighbours are in hcp and fcc?
difference between schottky defect and frenkel 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)
what is the full form of hcp and ccp?
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?
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
Strontium chloride has a fluorite structure, which of the following statement is true ?
1. The strontium ions are in a body-centered cubic arrangement
2. The strontium ions are in a face-centered cubic arrangement
3. each chloride ion is at the centre of a cube of 8 strontium ions
4. each strontium ion is at the centre of a tetrahedron of 4 chloride ions
which stoichiometric defect in crystals increases the density of a solid?
What are non-polar molecular solids?
Ques.Which point defect in its crystal units alters the density of a solid?
(1 mark)
2008 CBSE Delhi
Sol:Schottky defect in crystals units alters the density of a solid.
it isnt only schottky defect isnt it? it can also be vacancy and interstitial defect isnt it?
What is the maximum possible coordination No. of an atom in a hcp crystal structure?
whta type of crystal defect is produced when NaCl is doped with MgCl2?
Diamond is hard and a bad conductor of electricity while graphite is soft and a good conductor of electricity..Explain state of hybridisation of carbon in both in both substance....
pls explain metal excess and metal deficiency defect again...or by a video...ASAP
which of these two CdCl2 or NaCl will produce schottky defect if added to AgCl crystal ?
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..
name the crystal class for which all four types of unit cells are possible .
can u store copper sulphate solution in zinc pot?
conductivity of silicon increases on doping it with phosphorus reason
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?
(the question is from relative molecular mass and mole)
What is the weight of one mole of solute,0.132g of which in 29.70 of benzene gave a freezing point depression of 0.108K?Kf for C6H6 is 5.12 K mol-1 kg .
(Ans is 210.69)
WHT IS OCTAHEDRAL VOID AND TETRAHEDRAL VOIDS
Q1)What is the coordination no. of each type of ions in a rock-salt type crystal structure? how?
(the question is from Relative molecular mass and mole)
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
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Syllabus
Why is the dipole moment of NH3 greater then that of NF3 ??
chemistry chapter wise marks(cbse board)
what is F centre?
the most closely packed among the following crystal lattices is
(A)simple cubic close packing
(B)body centred cubic arrangement
(C)face centred cubic arrangement
(D)both fcc and bcc
If Nacl is doped with 10-3 mole % of Srcl2 , what is the concentration of cation vacancies?
(1) 6.023 x 1023 (2) 6.023 x 1018
(3) 6.023 x 1016 (4) 1.2046 x 1017
equivalent weight of silver nitrate
why are frenkel defects not found in pure alkali halides?
which of the following is an example of metallic crystal solid?
(a) C ( b) Si (c) W (d) AgCl
best reference books for class12 science[cbse]
1. what r true solids and pseudo solids?
2. why crystalline solids are true solids and amorphous solids r pseudo solids?
Q. Why old glass objects appear slightly milky instead of being transparent?
What is Schottky and Frenkel defects?
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?
, density = 7.9 g/cm^3
. Calculate the edge length of the unit cell?
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) x = 4, y = 6 (b) x = 3, y = 8 (c) x = 8, y = 6 (d) x = 8, y = 3
Which point defects lowers the density of a crystal?
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
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)
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?
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-
Why is this statement incorrect? explain please!
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?
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?
difference between molten and aqueous???
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!!!!!!.
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
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.......
how many second neighbours are in hcp and fcc?
difference between schottky defect and frenkel 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?what is the full form of hcp and ccp?
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?
(1) 75% of octahedral voids
(2) 50% of octahedral voids
(3) 12.5% of tetrahedral voids
(4) 25% of octahedral void
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
Strontium chloride has a fluorite structure, which of the following statement is true ?
1. The strontium ions are in a body-centered cubic arrangement
2. The strontium ions are in a face-centered cubic arrangement
3. each chloride ion is at the centre of a cube of 8 strontium ions
4. each strontium ion is at the centre of a tetrahedron of 4 chloride ions
which stoichiometric defect in crystals increases the density of a solid?
What are non-polar molecular solids?
Ques.Which point defect in its crystal units alters the density of a solid?
(1 mark)
2008 CBSE Delhi
Sol:Schottky defect in crystals units alters the density of a solid.
it isnt only schottky defect isnt it? it can also be vacancy and interstitial defect isnt it?
(i) Si O2 (ii) Mg O (iii) SO2(s) (iv) Cr O2
What is the maximum possible coordination No. of an atom in a hcp crystal structure?
whta type of crystal defect is produced when NaCl is doped with MgCl2?
Diamond is hard and a bad conductor of electricity while graphite is soft and a good conductor of electricity..Explain state of hybridisation of carbon in both in both substance....
pls explain metal excess and metal deficiency defect again...or by a video...ASAP
which of these two CdCl2 or NaCl will produce schottky defect if added to AgCl crystal ?
valency of silver nitrate
why frenkel defect does not change the density of agcl crystals???
Q.54. Which is true about Piezoelectric crystals?
(1) They produce an electric current on heating
(2) They produce an electric current when a mechanical stress is applied
(3) They are insulators
(4) They are magnetic in nature
what is the difference between isomorphism and polymorphism pls explain with some examples too..
Q. Octahedral void at edge center in ccp arrangement is equally distributed amongst
(1) 8 unit cells
(2) 6 unit cells
(3) 4 unit cells
(4) 2 unit cells
name the crystal class for which all four types of unit cells are possible .
can u store copper sulphate solution in zinc pot?
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."
conductivity of silicon increases on doping it with phosphorus reason
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?
(the question is from relative molecular mass and mole)
What is the weight of one mole of solute,0.132g of which in 29.70 of benzene gave a freezing point depression of 0.108K?Kf for C6H6 is 5.12 K mol-1 kg .
(Ans is 210.69)
WHT IS OCTAHEDRAL VOID AND TETRAHEDRAL VOIDS
(1) 6 (2) 8 (3) 12 (4) 4
Q1)What is the coordination no. of each type of ions in a rock-salt type crystal structure? how?
(the question is from Relative molecular mass and mole)
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?