15280 + Interview Questions in Chemistry Page 109 InterviewSolution

5401.	certain quantity p can be calculated using the relation P=under root ab^2/c to the power 4/5where a, b and c are some physical quantities with 1%,0.5%and 2.5%respectively the maximum %error in computation of P is
Answer» certain quantity p can be calculated using the relation P=under root ab^2/c to the power 4/5where a, b and c are some physical quantities with 1%,0.5%and 2.5%respectively the maximum %error in computation of P is

Discussion

5402.	(a) Determine the empirical formula of a compound containing 47.9% potassium, 5.5% beryllium and 46.6% fluorine by mass (Atomic weight of Be = 9; F = 19; K = 39). Work to one decimal place.(b) Given that the relative molecular mass of copper oxide is 80, what volume of ammonia (measured at STP) is required to completely reduce 120 g of copper oxide? The equation for the reaction is:3CuO + 2NH3 → 3Cu + 3H2O + N2(Volume occupied by 1 mole of gas at STP is 22.4 litres).
Answer» (a) Determine the empirical formula of a compound containing 47.9% potassium, 5.5% beryllium and 46.6% fluorine by mass (Atomic weight of Be = 9; F = 19; K = 39). Work to one decimal place. (b) Given that the relative molecular mass of copper oxide is 80, what volume of ammonia (measured at STP) is required to completely reduce 120 g of copper oxide? The equation for the reaction is: 3CuO + 2NH₃ $\overset{}{\to}$ 3Cu + 3H₂O + N₂ (Volume occupied by 1 mole of gas at STP is 22.4 litres).

Discussion

5403.	20. what will happen to the kienetic energy and potential energy when an electron in hydrogen atom is taken from fourth excited state to ground state?
Answer» 20. what will happen to the kienetic energy and potential energy when an electron in hydrogen atom is taken from fourth excited state to ground state?

Discussion

5404.	A reaction at equilibrium involving 2 moles each of PCl5, PCl3 and Cl2 is maintained at 250'C and the total pressure of 3 atm. the value of Kp is?
Answer» A reaction at equilibrium involving 2 moles each of PCl5, PCl3 and Cl2 is maintained at 250'C and the total pressure of 3 atm. the value of Kp is?

Discussion

5405.	What do you observe when(i) Concentrated nitric acid is dropped on a hot surface?(ii) Hydrogen sulphide is bubbled through conc. HNO3?(iii) Conc. HNO3 drops on the skin of a person?(iv) Scrap zinc is heated with conc. HNO3?
Answer» What do you observe when (i) Concentrated nitric acid is dropped on a hot surface? (ii) Hydrogen sulphide is bubbled through conc. HNO₃? (iii) Conc. HNO₃ drops on the skin of a person? (iv) Scrap zinc is heated with conc. HNO₃?

Discussion

5406.	Which among these is true about solids?
Answer» Which among these is true about solids?

Discussion

5407.	The fractional charge on each atom in HBr molecule is [Given that dipole moment of HBr= 0.78 D, Bond length of HBr = 1.41 A]
Answer» The fractional charge on each atom in HBr molecule is [Given that dipole moment of HBr= 0.78 D, Bond length of HBr = 1.41 A]

Discussion

5408.	A carbon compound on analysis gives the following percentage composition. Carbon 14.5 , hydrogen 1.8 chlorine 64.6 , oxygen 19.24 . The empirical formula of the compound is:
Answer» A carbon compound on analysis gives the following percentage composition. Carbon $14.5$ , hydrogen $1.8$ chlorine $64.6$ , oxygen $19.24$ . The empirical formula of the compound is:

Discussion

5409.	Which of the following compound is an acidic salt : 1. NaHSO4 2. NH4Cl 3. Ba(OH)Cl 4. Na2CO3
Answer» Which of the following compound is an acidic salt : 1. NaHSO4 2. NH4Cl 3. Ba(OH)Cl 4. Na2CO3

Discussion

5410.	The figure given below illustrates the apparatus used in the laboratory preparation of nitric acid. (a) Name A (a liquid), B (a solid) and C (a liquid). (Do not give the formulae). (b) Write an equation to show how nitric acid undergoes decomposition. (c) Write the equation for the reaction in which copper is oxidized by concentrated nitric acid.
Answer» The figure given below illustrates the apparatus used in the laboratory preparation of nitric acid. (a) Name A (a liquid), B (a solid) and C (a liquid). (Do not give the formulae). (b) Write an equation to show how nitric acid undergoes decomposition. (c) Write the equation for the reaction in which copper is oxidized by concentrated nitric acid.

5410.

The figure given below illustrates the apparatus used in the laboratory preparation of nitric acid. (a) Name A (a liquid), B (a solid) and C (a liquid). (Do not give the formulae). (b) Write an equation to show how nitric acid undergoes decomposition. (c) Write the equation for the reaction in which copper is oxidized by concentrated nitric acid.

Answer»

The figure given below illustrates the apparatus used in the laboratory preparation of nitric acid.

(a) Name A (a liquid), B (a solid) and C (a liquid). (Do not give the formulae).

(b) Write an equation to show how nitric acid undergoes decomposition.

(c) Write the equation for the reaction in which copper is oxidized by concentrated nitric acid.

Discussion

5411.	Write the electron-dot structure for sodium and chlorine atoms. How do these form a chemical bond? Name the type of bond so formed. Why does a compound has high melting point? [3 MARKS]
Answer» Write the electron-dot structure for sodium and chlorine atoms. How do these form a chemical bond? Name the type of bond so formed. Why does a compound has high melting point? [3 MARKS]

Discussion

5412.	42. Among sulphur dioxide and sulphure trioxide which one is more acidic and why?
Answer» 42. Among sulphur dioxide and sulphure trioxide which one is more acidic and why?

Discussion

5413.	Number of C–H bonds in ethane are ___.
Answer» Number of C–H bonds in ethane are ___.

Discussion

5414.	Give reasons for the following:Commercial concentrated nitric acid is yellow in colour, but when it is diluted with water, it turns colourless.Give one chemical test for nitric acid.
Answer» Give reasons for the following: Commercial concentrated nitric acid is yellow in colour, but when it is diluted with water, it turns colourless. Give one chemical test for nitric acid.

Discussion

5415.	Give reasons for the following.(a) Aluminium foils are used to wrap food items.(b) Immersion rods for heating liquids are made up of metallic substances(c) Copper cannot displace zinc from its salt solution.(d) Sodium and potassium are stored in kerosene.
Answer» Give reasons for the following. (a) Aluminium foils are used to wrap food items. (b) Immersion rods for heating liquids are made up of metallic substances (c) Copper cannot displace zinc from its salt solution. (d) Sodium and potassium are stored in kerosene.

Discussion

5416.	The process of loss of an electron in known as ______ and the process of gain of an electron is known as ________.
Answer» The process of loss of an electron in known as ______ and the process of gain of an electron is known as ________.

Discussion

5417.	Which of the following is dry and permanent bleaching agent(1) 03(2) Moist S02(3) H202(4) Cl2 water. Why it can not be H2O2
Answer» Which of the following is dry and permanent bleaching agent(1) 03(2) Moist S02(3) H202(4) Cl2 water. Why it can not be H2O2

Discussion

5418.	Which of the following will behave as a strong acid in aqueous solution?
Answer» Which of the following will behave as a strong acid in aqueous solution?

Discussion

5419.	Identify the impure metal electrode in the given figure for electrolytic refining.
Answer» Identify the impure metal electrode in the given figure for electrolytic refining.

Discussion

5420.	Which compound is the main component of Biogas?
Answer» Which compound is the main component of Biogas?

Discussion

5421.	My sir told that while writing subshell configuration we 1st write 3d and then 4s. But the electrons fill first in 4s and then in 3d My doubt is that which will come first 4s or 3d??why??
Answer» My sir told that while writing subshell configuration we 1st write 3d and then 4s. But the electrons fill first in 4s and then in 3d My doubt is that which will come first 4s or 3d??why??

Discussion

5422.	Question 6What are allotropes of carbon?
Answer» Question 6 What are allotropes of carbon?

5422.

Question 6What are allotropes of carbon?

Answer»

Question 6

What are allotropes of carbon?

Discussion

5423.	33. Chlorine gas on reaction with slaked lime and terpentine gives??
Answer» 33. Chlorine gas on reaction with slaked lime and terpentine gives??

Discussion

5424.	Silicon belonging to same group as Carbon and yet cannot form compounds like Carbon. Why?
Answer» Silicon belonging to same group as Carbon and yet cannot form compounds like Carbon. Why?

Discussion

5425.	What is a buffer solution?
Answer» What is a buffer solution?

Discussion

5426.	What are allotropes?
Answer» What are allotropes?

Discussion

5427.	What is the reaction of acetone in the presence of ''dilute sulphuric acid''?
Answer» What is the reaction of acetone in the presence of ''dilute sulphuric acid''?

Discussion

5428.	In the following sequence of reactions, A and D respectively are :A 4KOH, O2 −−−−−−−−→2B(Green)+2H2O3B 4HCl −−−−→2C(Purple)+MnO2+2H2O2C H2O,KI −−−−−−→2A+2KOH+D
Answer» In the following sequence of reactions, A and D respectively are : $A 4 K O H, O_{2} - ------- \to 2 B (Green) + 2 H_{2} O$ $3 B 4 H C l - --- \to 2 C (Purple) + M n O_{2} + 2 H_{2} O$ $2 C H_{2} O, K I - ----- \to 2 A + 2 K O H + D$

Discussion

5429.	Water is a combination of hydrogen and oxygen. How would you prove that water is a pure substance and not a mixture?
Answer» Water is a combination of hydrogen and oxygen. How would you prove that water is a pure substance and not a mixture?

Discussion

5430.	Calculate the molarity of a solution of ethanol in water, in which the mole fraction ofethanol is O.040 (assume the density of water to be one)
Answer» Calculate the molarity of a solution of ethanol in water, in which the mole fraction ofethanol is O.040 (assume the density of water to be one)

Discussion

5431.	B has two isotopes B^10(19%) and B^11(81%).The atomic mass of B is?
Answer» B has two isotopes B^10(19%) and B^11(81%).The atomic mass of B is?

Discussion

5432.	Carbon dioxide gas is liberated when HCl acid is added to:
Answer» Carbon dioxide gas is liberated when HCl acid is added to:

Discussion

5433.	How to calculate equivalent mass of a compound?
Answer» How to calculate equivalent mass of a compound?

Discussion

5434.	The structural formula of Indigo dye is:
Answer» The structural formula of Indigo dye is:

Discussion

5435.	An organisc compound, whose vapour density is 45, has the following percentage composition, H = 2.22 % O = 71 . 19% and remaining carbon. Calculate: (a) its empirical formula, (b) its molecular formula.
Answer» An organisc compound, whose vapour density is 45, has the following percentage composition, H = 2.22 % O = 71 . 19% and remaining carbon. Calculate: (a) its empirical formula, (b) its molecular formula.

5435.

An organisc compound, whose vapour density is 45, has the following percentage composition, H = 2.22 % O = 71 . 19% and remaining carbon. Calculate: (a) its empirical formula, (b) its molecular formula.

Answer»

An organisc compound, whose vapour density is 45, has the following percentage composition,
H = 2.22 % O = 71 . 19% and remaining carbon.

Calculate:
(a) its empirical formula, (b) its molecular formula.

Discussion

5436.	How does graphite act as a lubricant ?
Answer» How does graphite act as a lubricant ?

Discussion

5437.	F=ma drive
Answer» F=ma drive

Discussion

5438.

Which gas is formed when an amphoteric metal reacts with a strong base?

Answer»

Which gas is formed when an amphoteric metal reacts with a strong base?

Discussion

5439.	Products obtained when Conc.HNO3 (Nitric acid ) is heated.
Answer» Products obtained when Conc. $H N O_{3}$ (Nitric acid ) is heated.

Discussion

5440.	In a reversible reaction, the role played by a catalyst is to
Answer» In a reversible reaction, the role played by a catalyst is to

Discussion

5441.	What do you observe when ammonia hydroxide is added to the aqueous solution of : (a) FeSO4, (b) Iron (III) chloride, (c) Lead nitrate, (d) Zinc nitrate ?
Answer» What do you observe when ammonia hydroxide is added to the aqueous solution of : (a) $F e S O_{4}$ , (b) Iron (III) chloride, (c) Lead nitrate, (d) Zinc nitrate ?

5441.

What do you observe when ammonia hydroxide is added to the aqueous solution of : (a) FeSO4, (b) Iron (III) chloride, (c) Lead nitrate, (d) Zinc nitrate ?

Answer»

What do you observe when ammonia hydroxide is added to the aqueous solution of :

(a) $F e S O_{4}$ , (b) Iron (III) chloride,

(c) Lead nitrate, (d) Zinc nitrate ?

Discussion

5442.	The chemical formula of haematite is:
Answer» The chemical formula of haematite is:

Discussion

5443.	why sulphur disappear when boiled with aqueous solution of sodium sulphite
Answer» why sulphur disappear when boiled with aqueous solution of sodium sulphite

Discussion

5444.	Give reasons for the following:(i) In laboratory preparation of nitric acid all the apparatus including cork should be made up of glass.(ii) Commercial nitric acid is yellow in colour, but when it is diluted with water, it turns colourless.(iii) Aluminium does not react with nitric acid of any concentration.(iv) Conc. nitric acid renders iron passive.(v) Nitric acid is used in purification of gold.(vi) Aqua regia dissolves gold and platinum.(vii) Nitric acid usually does not yield hydrogen from acids.(viii) Lightning is a blessing in disguise.(ix) Concentrated nitric acid is brown in colour.(x) Concentrated nitric acid is a stronger oxidizing agent.
Answer» Give reasons for the following: (i) In laboratory preparation of nitric acid all the apparatus including cork should be made up of glass. (ii) Commercial nitric acid is yellow in colour, but when it is diluted with water, it turns colourless. (iii) Aluminium does not react with nitric acid of any concentration. (iv) Conc. nitric acid renders iron passive. (v) Nitric acid is used in purification of gold. (vi) Aqua regia dissolves gold and platinum. (vii) Nitric acid usually does not yield hydrogen from acids. (viii) Lightning is a blessing in disguise. (ix) Concentrated nitric acid is brown in colour. (x) Concentrated nitric acid is a stronger oxidizing agent.

Discussion

5445.	'In a group, the atomic radii increase with increasing period number', explain this statement and justify it with reference to group 17.
Answer» 'In a group, the atomic radii increase with increasing period number', explain this statement and justify it with reference to group 17.

Discussion

5446.

Sodium hydroxide solution is added to the solutions containing the ions mentioned in List X. List Y gives the details of the precipitate. Match the ions with their coloured precipitates. List X List Y (i) Pb2+ (A) Reddish brown (ii) Fe2+ (B) White insoluble in excess (iii) Zn2+ (C) Dirty green (iv) Fe3+ (D) White soluble in excess (v) Cu2+ (E) White soluble in excess (vi) Ca2+ (F) Blue

Answer» Sodium hydroxide solution is added to the solutions containing the ions mentioned in List X. List Y gives the details of the precipitate. Match the ions with their coloured precipitates.

List X	List Y
(i) Pb²⁺	(A) Reddish brown
(ii) Fe²⁺	(B) White insoluble in excess
(iii) Zn²⁺	(C) Dirty green
(iv) Fe³⁺	(D) White soluble in excess
(v) Cu²⁺	(E) White soluble in excess
(vi) Ca²⁺	(F) Blue

Discussion

5447.	The half life period for catalytics decompostion of AB_{3 }at 50 mm is found to be 4 hr and at 100 mm it is 2 hr . the order of reaction is (1) 3 (2) 1 (3) 2 (4)
Answer» The half life period for catalytics decompostion of AB_{3 }at 50 mm is found to be 4 hr and at 100 mm it is 2 hr . the order of reaction is (1) 3 (2) 1 (3) 2 (4)

Discussion

5448.	11.H2O2 when treated with excess of Kl in appropriate medium it produces a solution which is titrated against hypo solution in acidic solution. which of the following is true for reaction mixture at equivalence point? 1) Final solution contains sulphate ions which are produced in reaction 2) in entire experiment H2O2 is the only oxidizing agent 3) in entire experiments reducing agent must contain iodine 4) final solution contains iodine with single oxidation number
Answer» 11.H2O2 when treated with excess of Kl in appropriate medium it produces a solution which is titrated against hypo solution in acidic solution. which of the following is true for reaction mixture at equivalence point? 1) Final solution contains sulphate ions which are produced in reaction 2) in entire experiment H2O2 is the only oxidizing agent 3) in entire experiments reducing agent must contain iodine 4) final solution contains iodine with single oxidation number

Discussion

5449.	47. Arrange in the increasing Order of melting point of following i) liI NaI ki rbI CsI ii)bef2 mgf2 caf2 srf2 baf2
Answer» 47. Arrange in the increasing Order of melting point of following i) liI NaI ki rbI CsI ii)bef2 mgf2 caf2 srf2 baf2

Discussion

5450.	Why before electroplating ,a brass spoon is first cleaned and then is washed in the hot solution of caustic soda followed by dilute hydrochloric acid and water after which it is thoroughly wash with detergent and several times with distilled water?
Answer» Why before electroplating ,a brass spoon is first cleaned and then is washed in the hot solution of caustic soda followed by dilute hydrochloric acid and water after which it is thoroughly wash with detergent and several times with distilled water?

Discussion

Explore topic-wise InterviewSolutions in .

certain quantity p can be calculated using the relation P=under root ab^2/c to the power 4/5where a, b and c are some physical quantities with 1%,0.5%and 2.5%respectively the maximum %error in computation of P is

20. what will happen to the kienetic energy and potential energy when an electron in hydrogen atom is taken from fourth excited state to ground state?

A reaction at equilibrium involving 2 moles each of PCl5, PCl3 and Cl2 is maintained at 250'C and the total pressure of 3 atm. the value of Kp is?

What do you observe when(i) Concentrated nitric acid is dropped on a hot surface?(ii) Hydrogen sulphide is bubbled through conc. HNO3?(iii) Conc. HNO3 drops on the skin of a person?(iv) Scrap zinc is heated with conc. HNO3?

Which among these is true about solids?

The fractional charge on each atom in HBr molecule is [Given that dipole moment of HBr= 0.78 D, Bond length of HBr = 1.41 A]

A carbon compound on analysis gives the following percentage composition. Carbon 14.5 , hydrogen 1.8 chlorine 64.6 , oxygen 19.24 . The empirical formula of the compound is:

Which of the following compound is an acidic salt : 1. NaHSO4 2. NH4Cl 3. Ba(OH)Cl 4. Na2CO3

Write the electron-dot structure for sodium and chlorine atoms. How do these form a chemical bond? Name the type of bond so formed. Why does a compound has high melting point? [3 MARKS]

42. Among sulphur dioxide and sulphure trioxide which one is more acidic and why?

Number of C–H bonds in ethane are ___.

Give reasons for the following:Commercial concentrated nitric acid is yellow in colour, but when it is diluted with water, it turns colourless.Give one chemical test for nitric acid.

Give reasons for the following.​(a) Aluminium foils are used to wrap food items.​(b) Immersion rods for heating liquids are made up of metallic substances(c) Copper cannot displace zinc from its salt solution.​(d) Sodium and potassium are stored in kerosene.​

The process of loss of an electron in known as ______ and the process of gain of an electron is known as ________.

Which of the following is dry and permanent bleaching agent(1) 03(2) Moist S02(3) H202(4) Cl2 water. Why it can not be H2O2

Which of the following will behave as a strong acid in aqueous solution?

Identify the impure metal electrode in the given figure for electrolytic refining.

Which compound is the main component of Biogas?

My sir told that while writing subshell configuration we 1st write 3d and then 4s. But the electrons fill first in 4s and then in 3d My doubt is that which will come first 4s or 3d??why??

Question 6What are allotropes of carbon?

33. Chlorine gas on reaction with slaked lime and terpentine gives??

Silicon belonging to same group as Carbon and yet cannot form compounds like Carbon. Why?

What is a buffer solution?

What are allotropes?

What is the reaction of acetone in the presence of ''dilute sulphuric acid''?

In the following sequence of reactions, A and D respectively are :A 4KOH, O2 −−−−−−−−→2B(Green)+2H2O3B 4HCl −−−−→2C(Purple)+MnO2+2H2O2C H2O,KI −−−−−−→2A+2KOH+D

Water is a combination of hydrogen and oxygen. How would you prove that water is a pure substance and not a mixture?

Calculate the molarity of a solution of ethanol in water, in which the mole fraction ofethanol is O.040 (assume the density of water to be one)

B has two isotopes B^10(19%) and B^11(81%).The atomic mass of B is?

Carbon dioxide gas is liberated when HCl acid is added to:

How to calculate equivalent mass of a compound?

The structural formula of Indigo dye is:

An organisc compound, whose vapour density is 45, has the following percentage composition, H = 2.22 % O = 71 . 19% and remaining carbon. Calculate: (a) its empirical formula, (b) its molecular formula.

How does graphite act as a lubricant ?

F=ma drive

Which gas is formed when an amphoteric metal reacts with a strong base?

Products obtained when Conc.HNO3 (Nitric acid ) is heated.

In a reversible reaction, the role played by a catalyst is to

What do you observe when ammonia hydroxide is added to the aqueous solution of : (a) FeSO4, (b) Iron (III) chloride, (c) Lead nitrate, (d) Zinc nitrate ?

The chemical formula of haematite is:

why sulphur disappear when boiled with aqueous solution of sodium sulphite

'In a group, the atomic radii increase with increasing period number', explain this statement and justify it with reference to group 17.

The half life period for catalytics decompostion of AB_{3 }at 50 mm is found to be 4 hr and at 100 mm it is 2 hr . the order of reaction is (1) 3 (2) 1 (3) 2 (4)

47. Arrange in the increasing Order of melting point of following i) liI NaI ki rbI CsI ii)bef2 mgf2 caf2 srf2 baf2

Why before electroplating ,a brass spoon is first cleaned and then is washed in the hot solution of caustic soda followed by dilute hydrochloric acid and water after which it is thoroughly wash with detergent and several times with distilled water?

Give reasons for the following.(a) Aluminium foils are used to wrap food items.(b) Immersion rods for heating liquids are made up of metallic substances(c) Copper cannot displace zinc from its salt solution.(d) Sodium and potassium are stored in kerosene.

The process of loss of an electron in known as and the process of gain of an electron is known as __.