7248 + Interview Questions in Chemistry Page 3 InterviewSolution

101.	why can dilute solution of hydrogen peroxide not concentrated by heating.how can a concentrated solution of hydrogen peroxide be obtained?refer exemplar problem
Answer» why can dilute solution of hydrogen peroxide not concentrated by heating.how can a concentrated solution of hydrogen peroxide be obtained? refer exemplar problem

Discussion

102.	Refining of metals is done by:
Answer» Refining of metals is done by:

Discussion

103.	2. Why does kerosene burn with a blue flame in wick stove but produces a yellow flame when burnt in a lamp
Answer» 2. Why does kerosene burn with a blue flame in wick stove but produces a yellow flame when burnt in a lamp

Discussion

104.	Will a certain gas kept in large room and the same amount of the same gas compressed in a cylinder have the same mass?
Answer» Will a certain gas kept in large room and the same amount of the same gas compressed in a cylinder have the same mass?

Discussion

105.	N2O4 AT 2 ATM IS INTRODUCED IN A 12L RIGID VESSEL AT 300 K .TEMP. IS INCRESED TO 600K DUE TO WHICH 50% OF N2O4 DISSOCIATE INTO NO2.CALCULATE FINAL PRESSURE OF SYSTEM
Answer» N2O4 AT 2 ATM IS INTRODUCED IN A 12L RIGID VESSEL AT 300 K .TEMP. IS INCRESED TO 600K DUE TO WHICH 50% OF N2O4 DISSOCIATE INTO NO2.CALCULATE FINAL PRESSURE OF SYSTEM

Discussion

106.	ntQ.1. A + B -------> C H = +60 KJ/moln ntEa is 150 KJ. What is the activation energy for a backward reaction?n
Answer» ntQ.1. A + B -------> C H = +60 KJ/moln ntEa is 150 KJ. What is the activation energy for a backward reaction?n

Discussion

107.	Assertion (A): Permanent hardness of water is removed by treatment with washing soda.Reason(R): Washing soda reacts with soluble magnesium and calcium sulphate to form water-soluble compounds.
Answer» Assertion (A): Permanent hardness of water is removed by treatment with washing soda. Reason(R): Washing soda reacts with soluble magnesium and calcium sulphate to form water-soluble compounds.

Discussion

108.	57.The volume of co2 obtained (at STP) by the complete combustion of 24g of methane gas is
Answer» 57.The volume of co2 obtained (at STP) by the complete combustion of 24g of methane gas is

Discussion

109.	11. heat of which of the following reactions gives the enthalpy of formation directly 1 H2 (g) + I2 (g) == 2HI(g) 2 N2(g)+ 3H2(g) ==== 2NH3(g) 3 C graphite + 2H2(g) =====CH4(g) 4 all of these
Answer» 11. heat of which of the following reactions gives the enthalpy of formation directly 1 H2 (g) + I2 (g) == 2HI(g) 2 N2(g)+ 3H2(g) ==== 2NH3(g) 3 C graphite + 2H2(g) =====CH4(g) 4 all of these

Discussion

110.	Identify the products in which Paraffin wax is used.
Answer» Identify the products in which Paraffin wax is used.

Discussion

111.	How do insects such as pond skaters stay afloat on water?
Answer» How do insects such as pond skaters stay afloat on water?

Discussion

112.	Question 7Metals generally react with dilute acids to produce hydrogen gas. Which one of the following metals does not react with dilute hydrochloric acid?(a) magnesium(b) aluminium(c) iron(d) copper
Answer» Question 7 Metals generally react with dilute acids to produce hydrogen gas. Which one of the following metals does not react with dilute hydrochloric acid? (a) magnesium (b) aluminium (c) iron (d) copper

Discussion

113.	The effective collision of molecules increases because of the increase in their
Answer» The effective collision of molecules increases because of the increase in their

Discussion

114.	Fill in the following balnks with suitable words: (a) Metals are ........................... conductors of heat and ............................ (b) Most non-metals are ........................... conductors of heat and ........................... (c) Phosphorous is a very ........................... non-metal. (d) Metals react with acids to produce ........................... gas. (e) Iron is more ........................... than copper. (f) Metals form ........................... oxides whereas non-metals form ........................... oxides. (g) Sulphur forms ........................... oxide whereas magnesium forms ........................... oxide. (h) A non-metal is used to make an antiseptic solution called tincture ...........................
Answer» Fill in the following balnks with suitable words: (a) Metals are ........................... conductors of heat and ............................ (b) Most non-metals are ........................... conductors of heat and ........................... (c) Phosphorous is a very ........................... non-metal. (d) Metals react with acids to produce ........................... gas. (e) Iron is more ........................... than copper. (f) Metals form ........................... oxides whereas non-metals form ........................... oxides. (g) Sulphur forms ........................... oxide whereas magnesium forms ........................... oxide. (h) A non-metal is used to make an antiseptic solution called tincture ...........................

114.

Fill in the following balnks with suitable words: (a) Metals are ........................... conductors of heat and ............................ (b) Most non-metals are ........................... conductors of heat and ........................... (c) Phosphorous is a very ........................... non-metal. (d) Metals react with acids to produce ........................... gas. (e) Iron is more ........................... than copper. (f) Metals form ........................... oxides whereas non-metals form ........................... oxides. (g) Sulphur forms ........................... oxide whereas magnesium forms ........................... oxide. (h) A non-metal is used to make an antiseptic solution called tincture ...........................

Answer»

Fill in the following balnks with suitable words:

(a) Metals are ........................... conductors of heat and ............................

(b) Most non-metals are ........................... conductors of heat and ...........................

(c) Phosphorous is a very ........................... non-metal.

(d) Metals react with acids to produce ........................... gas.

(e) Iron is more ........................... than copper.

(f) Metals form ........................... oxides whereas non-metals form ........................... oxides.

(g) Sulphur forms ........................... oxide whereas magnesium forms ........................... oxide.

(h) A non-metal is used to make an antiseptic solution called tincture ...........................

Discussion

115.	Describecharacteristics and uses of coke.
Answer» Describe characteristics and uses of coke.

Discussion

116.	The temporary hardness of water is due to:
Answer» The temporary hardness of water is due to:

Discussion

117.	what is order of overlapping of sigma and pi bonds.
Answer» what is order of overlapping of sigma and pi bonds.

Discussion

118.	When you look around and start writing the things seen and the materials used in making those things, to your surprise you will find that maximum things are made up of plastics, why is it so?
Answer» When you look around and start writing the things seen and the materials used in making those things, to your surprise you will find that maximum things are made up of plastics, why is it so?

Discussion

119.	Two metallic oxides contain 27.6% and 30%oxygen respectively. If the formula of the first oxideis X304, that of the second will be
Answer» Two metallic oxides contain 27.6% and 30%oxygen respectively. If the formula of the first oxideis X304, that of the second will be

Discussion

120.	Fire undergoes a chemical reaction known as ___.
Answer» Fire undergoes a chemical reaction known as ___.

Discussion

121.	Name one source and one harmful effect of each of the following air pollutants : (a) Sulphur dioxide (b) Nitrogen oxides (c) Carbon monoxide (d) Chlorofluorocarbons (CFCs)
Answer» Name one source and one harmful effect of each of the following air pollutants : (a) Sulphur dioxide (b) Nitrogen oxides (c) Carbon monoxide (d) Chlorofluorocarbons (CFCs)

121.

Name one source and one harmful effect of each of the following air pollutants : (a) Sulphur dioxide (b) Nitrogen oxides (c) Carbon monoxide (d) Chlorofluorocarbons (CFCs)

Answer»

Name one source and one harmful effect of each of the following air pollutants :

(a) Sulphur dioxide

(b) Nitrogen oxides

(c) Carbon monoxide

(d) Chlorofluorocarbons (CFCs)

Discussion

122.	at 40degrees the vapour pressure of mix of methyl alcohol ethyl alcohol is represented by P=199x+135 where x is mol fraction of methyl alcohol .what are thressure of pure ethyl alcohol at 40degrees
Answer» at 40degrees the vapour pressure of mix of methyl alcohol ethyl alcohol is represented by P=199x+135 where x is mol fraction of methyl alcohol .what are thressure of pure ethyl alcohol at 40degrees

Discussion

123.	Gasoline is produced by refining which fossil fuel?
Answer» Gasoline is produced by refining which fossil fuel?

Discussion

124.	the ratio of mass of an electron to that of the mass of hydrogen atom is
Answer» the ratio of mass of an electron to that of the mass of hydrogen atom is

Discussion

125.	Question 10A change in the physical state can be brought about(a) Only when energy is given to the system(b) Only when energy is taken (c) When energy is either given to, or taken out from the system(d) Without any energy change
Answer» Question 10 A change in the physical state can be brought about (a) Only when energy is given to the system (b) Only when energy is taken (c) When energy is either given to, or taken out from the system (d) Without any energy change

Discussion

126.	1) What is critical temperarture?2) What is the critical temperature of water?
Answer» 1) What is critical temperarture? 2) What is the critical temperature of water?

Discussion

127.	Identify the correct balanced equation from the following chemical reactions.
Answer» Identify the correct balanced equation from the following chemical reactions.

Discussion

128.	Question 11Fresh milk has a pH of 6. How do you think the pH will change as the milk turns into curd? Explain your answer.
Answer» Question 11 Fresh milk has a pH of 6. How do you think the pH will change as the milk turns into curd? Explain your answer.

128.

Question 11Fresh milk has a pH of 6. How do you think the pH will change as the milk turns into curd? Explain your answer.

Answer»

Question 11

Fresh milk has a pH of 6. How do you think the pH will change as the milk turns into curd? Explain your answer.

Discussion

129.	Which zone of a candle flame is the hottest ?
Answer» Which zone of a candle flame is the hottest ?

Discussion

130.	Question 8 Categorize the materials of the following products into 'can be recycled' and 'cannot be recycled'. Telephone instruments, plastic toys, cooker handles, carry bags, ball point pens, plastic bowls, plastic covering on electrical wires, plastic chairs, electrical switches.
Answer» Question 8 Categorize the materials of the following products into 'can be recycled' and 'cannot be recycled'. Telephone instruments, plastic toys, cooker handles, carry bags, ball point pens, plastic bowls, plastic covering on electrical wires, plastic chairs, electrical switches.

Discussion

131.	Aluminium oxide reacts with hot concentrated solution of sodium hydroxide to form:
Answer» Aluminium oxide reacts with hot concentrated solution of sodium hydroxide to form:

Discussion

132.	The decomposition of ozone proceeds as O3⇔O2+O(fast)O+O3→2O2(slow) The rate expression should be
Answer» The decomposition of ozone proceeds as $O_{3} \Leftrightarrow O_{2} + O (f a s t) O + O_{3} \to 2 O_{2} (s l o w)$ The rate expression should be

Discussion

133.	the ratio of kinetic energy of a planet at perigee and apogee during its motion around the sun in elliptical orbit of eccentricity e is
Answer» the ratio of kinetic energy of a planet at perigee and apogee during its motion around the sun in elliptical orbit of eccentricity e is

Discussion

134.	Oil is forced out of the earth during the primary recovery process due to:
Answer» Oil is forced out of the earth during the primary recovery process due to:

Discussion

135.	Match the following acids with the food substance in which they are present. (a) Buttermilk (b) Vinegar (c) Tamarind (d) Lemon (i) Tartaric Acid (ii) Acetic Acid (iii) Citric Acid (iv) Lactic Acid
Answer» Match the following acids with the food substance in which they are present. (a) Buttermilk (b) Vinegar (c) Tamarind (d) Lemon (i) Tartaric Acid (ii) Acetic Acid (iii) Citric Acid (iv) Lactic Acid

135.

Match the following acids with the food substance in which they are present. (a) Buttermilk (b) Vinegar (c) Tamarind (d) Lemon (i) Tartaric Acid (ii) Acetic Acid (iii) Citric Acid (iv) Lactic Acid

Answer»

Match the following acids with the food substance in which they are present.

(a) Buttermilk (b) Vinegar (c) Tamarind (d) Lemon

(i) Tartaric Acid (ii) Acetic Acid (iii) Citric Acid (iv) Lactic Acid

Discussion

136.	Velocity of electron in the nth bohr orbit of hydrogen like atom is given by 2.18×10raise to power 8Z/n cm/s the velocity of electron in the first bohr orbit of hydrogen atom ? (a) c/1.37 (b)c/13.7 (c)c/137 (d)c/1370
Answer» Velocity of electron in the nth bohr orbit of hydrogen like atom is given by 2.18×10raise to power 8Z/n cm/s the velocity of electron in the first bohr orbit of hydrogen atom ? (a) c/1.37 (b)c/13.7 (c)c/137 (d)c/1370

Discussion

137.	What is acrylic ? State one important property of acrylic.
Answer» What is acrylic ? State one important property of acrylic.

Discussion

138.	Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?
Answer» Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?

Discussion

139.	What would you observe on adding dilute hydrochloric acid to (i) sodium bicarbonate placed in a test tube? (ii) zinc metal in a test tube? [3 MARKS]
Answer» What would you observe on adding dilute hydrochloric acid to (i) sodium bicarbonate placed in a test tube? (ii) zinc metal in a test tube? [3 MARKS]

Discussion

140.	The difference between number of shared electron pairs and unpaired electrons in NH_{3 }is a.4 b.2 c.0 d.3 which is correct and why
Answer» The difference between number of shared electron pairs and unpaired electrons in NH_{3 }is a.4 b.2 c.0 d.3 which is correct and why

Discussion

141.	What is a Kinetic energy ?
Answer» What is a Kinetic energy ?

Discussion

142.	How many valency electrons are present in z=26
Answer» How many valency electrons are present in z=26

Discussion

143.	To set fire to a combustible substance, you have to heat it to a certain minimum temperature. What is the minimum temperature called? If this minimum temperature is very low for a certain substance, what is the substance called?
Answer» To set fire to a combustible substance, you have to heat it to a certain minimum temperature. What is the minimum temperature called? If this minimum temperature is very low for a certain substance, what is the substance called?

Discussion

144.	Why should curd and sour substances not be kept in brass and copper vessels?
Answer» Why should curd and sour substances not be kept in brass and copper vessels?

Discussion

145.	Match the following : Column AColumn B1.A product of incomplete burning (a) Hopcolite 2.Nature of carbon monoxide (b) Combustible gas 3.A compound formed by the combination (c) Carboxy-haemoglobinof haemoglobin and carbon monoxide4. A mixture of metallic oxides (d) Carbon monoxide 5.Carbon monoxide (e)Highly poisonous
Answer» Match the following : $\begin{matrix} Column A & Column B 1. A product of incomplete burning & (a) Hopcolite 2. Nature of carbon monoxide & (b) Combustible gas 3. A compound formed by the combination & (c) Carboxy-haemoglobin of haemoglobin and carbon monoxide 4. A mixture of metallic oxides & (d) Carbon monoxide 5. Carbon monoxide & (e)Highly poisonous \end{matrix}$

145.

Match the following : Column AColumn B1.A product of incomplete burning (a) Hopcolite 2.Nature of carbon monoxide (b) Combustible gas 3.A compound formed by the combination (c) Carboxy-haemoglobinof haemoglobin and carbon monoxide4. A mixture of metallic oxides (d) Carbon monoxide 5.Carbon monoxide (e)Highly poisonous

Answer»

Match the following :

$\begin{matrix} Column A & Column B 1. A product of incomplete burning & (a) Hopcolite 2. Nature of carbon monoxide & (b) Combustible gas 3. A compound formed by the combination & (c) Carboxy-haemoglobin of haemoglobin and carbon monoxide 4. A mixture of metallic oxides & (d) Carbon monoxide 5. Carbon monoxide & (e)Highly poisonous \end{matrix}$

Discussion

146.	How rusting takes place?
Answer» How rusting takes place?

Discussion

147.	1 kg of ice at -10 degree Celsius mixed with 4.4kg water at 30 degree. Final temperature of mixture is
Answer» 1 kg of ice at -10 degree Celsius mixed with 4.4kg water at 30 degree. Final temperature of mixture is

Discussion

148.	Choose the most appropriate answer from the options given below :(a) a mixture of sand and ammonium chloride can be separated by(i) filtration(ii) distillation(iii) sublimation(iv) crystallisation(b) A pair of metalloids are(i) Na and Mg(ii) B and Si(iii) C and P(iv) He and Ar(c) Which of the following property is not shown by compounds ?(i) They are heterogeneous.(ii) They are homogeneous.(iii) They have definite molecular formulae.(iv) They have fixed melting and boiling points.(d) A solvent of Iodine is(i) Water(ii) Kerosene oil(iii) Alcohol(iv) Petrol(e) Which of the gas is highly soluble in water ?(i) Ammonia(ii) Nitrogen(iii) Carbon monoxide(iv) Oxygen
Answer» Choose the most appropriate answer from the options given below : (a) a mixture of sand and ammonium chloride can be separated by (i) filtration (ii) distillation (iii) sublimation (iv) crystallisation (b) A pair of metalloids are (i) Na and Mg (ii) B and Si (iii) C and P (iv) He and Ar (c) Which of the following property is not shown by compounds ? (i) They are heterogeneous. (ii) They are homogeneous. (iii) They have definite molecular formulae. (iv) They have fixed melting and boiling points. (d) A solvent of Iodine is (i) Water (ii) Kerosene oil (iii) Alcohol (iv) Petrol (e) Which of the gas is highly soluble in water ? (i) Ammonia (ii) Nitrogen (iii) Carbon monoxide (iv) Oxygen

148.

Choose the most appropriate answer from the options given below :(a) a mixture of sand and ammonium chloride can be separated by(i) filtration(ii) distillation(iii) sublimation(iv) crystallisation(b) A pair of metalloids are(i) Na and Mg(ii) B and Si(iii) C and P(iv) He and Ar(c) Which of the following property is not shown by compounds ?(i) They are heterogeneous.(ii) They are homogeneous.(iii) They have definite molecular formulae.(iv) They have fixed melting and boiling points.(d) A solvent of Iodine is(i) Water(ii) Kerosene oil(iii) Alcohol(iv) Petrol(e) Which of the gas is highly soluble in water ?(i) Ammonia(ii) Nitrogen(iii) Carbon monoxide(iv) Oxygen

Answer»

Choose the most appropriate answer from the options given below :

(a) a mixture of sand and ammonium chloride can be separated by

(i) filtration

(ii) distillation

(iii) sublimation

(iv) crystallisation

(b) A pair of metalloids are

(i) Na and Mg

(ii) B and Si

(iii) C and P

(iv) He and Ar

(c) Which of the following property is not shown by compounds ?

(i) They are heterogeneous.

(ii) They are homogeneous.

(iii) They have definite molecular formulae.

(iv) They have fixed melting and boiling points.

(d) A solvent of Iodine is

(i) Water

(ii) Kerosene oil

(iii) Alcohol

(iv) Petrol

(e) Which of the gas is highly soluble in water ?

(i) Ammonia

(ii) Nitrogen

(iii) Carbon monoxide

(iv) Oxygen

Discussion

149.	A compound AB has a rock salt type structure with A:B=1:1. The formula weight of AB is 6.023 y g and the closest A−B distance is y1/3 nm. The density of lattice ( in kg m−3) is
Answer» A compound $A B$ has a rock salt type structure with $A : B = 1 : 1$ . The formula weight of $A B$ is $6.023 y g$ and the closest $A - B$ distance is $y^{1 / 3} nm$ . The density of lattice $({in kg m}^{- 3})$ is

Discussion

150.	in trigonal bipyramidal and pentagonal bipyramidal which one of axial and equatorial bond is longer
Answer» in trigonal bipyramidal and pentagonal bipyramidal which one of axial and equatorial bond is longer

Discussion

Explore topic-wise InterviewSolutions in .

why can dilute solution of hydrogen peroxide not concentrated by heating.how can a concentrated solution of hydrogen peroxide be obtained?refer exemplar problem

Refining of metals is done by:

2. Why does kerosene burn with a blue flame in wick stove but produces a yellow flame when burnt in a lamp

Will a certain gas kept in large room and the same amount of the same gas compressed in a cylinder have the same mass?

N2O4 AT 2 ATM IS INTRODUCED IN A 12L RIGID VESSEL AT 300 K .TEMP. IS INCRESED TO 600K DUE TO WHICH 50% OF N2O4 DISSOCIATE INTO NO2.CALCULATE FINAL PRESSURE OF SYSTEM

ntQ.1. A + B -------> C H = +60 KJ/moln ntEa is 150 KJ. What is the activation energy for a backward reaction?n

Assertion (A): Permanent hardness of water is removed by treatment with washing soda.Reason(R): Washing soda reacts with soluble magnesium and calcium sulphate to form water-soluble compounds.

57.The volume of co2 obtained (at STP) by the complete combustion of 24g of methane gas is

11. heat of which of the following reactions gives the enthalpy of formation directly 1 H2 (g) + I2 (g) == 2HI(g) 2 N2(g)+ 3H2(g) ==== 2NH3(g) 3 C graphite + 2H2(g) =====CH4(g) 4 all of these

Identify the products in which Paraffin wax is used.

How do insects such as pond skaters stay afloat on water?

Question 7Metals generally react with dilute acids to produce hydrogen gas. Which one of the following metals does not react with dilute hydrochloric acid?(a) magnesium(b) aluminium(c) iron(d) copper

The effective collision of molecules increases because of the increase in their

Describecharacteristics and uses of coke.

The temporary hardness of water is due to:

what is order of overlapping of sigma and pi bonds.

When you look around and start writing the things seen and the materials used in making those things, to your surprise you will find that maximum things are made up of plastics, why is it so?

Two metallic oxides contain 27.6% and 30%oxygen respectively. If the formula of the first oxideis X304, that of the second will be

Fire undergoes a chemical reaction known as ___.

Name one source and one harmful effect of each of the following air pollutants : (a) Sulphur dioxide (b) Nitrogen oxides (c) Carbon monoxide (d) Chlorofluorocarbons (CFCs)

at 40degrees the vapour pressure of mix of methyl alcohol ethyl alcohol is represented by P=199x+135 where x is mol fraction of methyl alcohol .what are thressure of pure ethyl alcohol at 40degrees

Gasoline is produced by refining which fossil fuel?

the ratio of mass of an electron to that of the mass of hydrogen atom is

Question 10A change in the physical state can be brought about(a) Only when energy is given to the system(b) Only when energy is taken (c) When energy is either given to, or taken out from the system(d) Without any energy change

1) What is critical temperarture?2) What is the critical temperature of water?

Identify the correct balanced equation from the following chemical reactions.

Question 11Fresh milk has a pH of 6. How do you think the pH will change as the milk turns into curd? Explain your answer.

Which zone of a candle flame is the hottest ?

Question 8 Categorize the materials of the following products into 'can be recycled' and 'cannot be recycled'. Telephone instruments, plastic toys, cooker handles, carry bags, ball point pens, plastic bowls, plastic covering on electrical wires, plastic chairs, electrical switches.

Aluminium oxide reacts with hot concentrated solution of sodium hydroxide to form:

The decomposition of ozone proceeds as O3⇔O2+O(fast)O+O3→2O2(slow) The rate expression should be

the ratio of kinetic energy of a planet at perigee and apogee during its motion around the sun in elliptical orbit of eccentricity e is

Oil is forced out of the earth during the primary recovery process due to:

Match the following acids with the food substance in which they are present. (a) Buttermilk (b) Vinegar (c) Tamarind (d) Lemon (i) Tartaric Acid (ii) Acetic Acid (iii) Citric Acid (iv) Lactic Acid

Velocity of electron in the nth bohr orbit of hydrogen like atom is given by 2.18×10raise to power 8Z/n cm/s the velocity of electron in the first bohr orbit of hydrogen atom ? (a) c/1.37 (b)c/13.7 (c)c/137 (d)c/1370

What is acrylic ? State one important property of acrylic.

Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?

What would you observe on adding dilute hydrochloric acid to (i) sodium bicarbonate placed in a test tube? (ii) zinc metal in a test tube? [3 MARKS]

The difference between number of shared electron pairs and unpaired electrons in NH_{3 }is a.4 b.2 c.0 d.3 which is correct and why

What is a Kinetic energy ?

How many valency electrons are present in z=26

To set fire to a combustible substance, you have to heat it to a certain minimum temperature. What is the minimum temperature called? If this minimum temperature is very low for a certain substance, what is the substance called?

Why should curd and sour substances not be kept in brass and copper vessels?

How rusting takes place?

1 kg of ice at -10 degree Celsius mixed with 4.4kg water at 30 degree. Final temperature of mixture is

A compound AB has a rock salt type structure with A:B=1:1. The formula weight of AB is 6.023 y g and the closest A−B distance is y1/3 nm. The density of lattice ( in kg m−3) is

in trigonal bipyramidal and pentagonal bipyramidal which one of axial and equatorial bond is longer