15280 + Interview Questions in Chemistry Page 142 InterviewSolution

7051.	General electronic configuration of lanthanides is
Answer» General electronic configuration of lanthanides is

Discussion

7052.	Write balanced equations to show the preparation of the following:(i) ethane from sodium propionate(ii) ethene from ethanol(iii) ethyne from calcium carbide(iv) ethanoic acid from ethane
Answer» Write balanced equations to show the preparation of the following: (i) ethane from sodium propionate (ii) ethene from ethanol (iii) ethyne from calcium carbide (iv) ethanoic acid from ethane

Discussion

7053.	Why should an equation be balanced? Explain with the help of a simple equation.
Answer» Why should an equation be balanced? Explain with the help of a simple equation.

Discussion

7054.	Name the metal of the filament of an electric current
Answer» Name the metal of the filament of an electric current

Discussion

7055.	In a fiven reaction, barium hydroxide reacts with ammonium chloride to from product X and Y. identify X and Y. Ba(OH)2 + NH4CI → X + Y
Answer» In a fiven reaction, barium hydroxide reacts with ammonium chloride to from product X and Y. identify X and Y. Ba(OH)₂ + NH₄CI → X + Y

7055.

In a fiven reaction, barium hydroxide reacts with ammonium chloride to from product X and Y. identify X and Y. Ba(OH)2 + NH4CI → X + Y

Answer»

In a fiven reaction, barium hydroxide reacts with ammonium chloride to from product X and Y.

identify X and Y.

Ba(OH)₂ + NH₄CI → X + Y

Discussion

7056.	If for an element (X), the values of successive ionization energies I1, I2, I3, I4 and I5 are 800, 2427, 3658, 25024, 32824 kJ mol−1 respectively, then the number of valence electrons present are:
Answer» If for an element $(X)$ , the values of successive ionization energies $I_{1}, I_{2}, I_{3}, I_{4}$ and $I_{5}$ are $800, 2427, 3658, 25024, 32824 {kJ mol}^{- 1}$ respectively, then the number of valence electrons present are:

Discussion

7057.	The strength of an acid depends on its tendency to:
Answer» The strength of an acid depends on its tendency to:

Discussion

7058.	I just wanted to know whether E0 value for Rubidium is more of Caesium
Answer» I just wanted to know whether E0 value for Rubidium is more of Caesium

Discussion

7059.	Which ahs stronger dπ- pπ bonding?Options PO4 3-, SO4 2-, SiO4 4-, ClO4-
Answer» Which ahs stronger dπ- pπ bonding? Options PO4 3-, SO4 2-, SiO4 4-, ClO4-

Discussion

7060.	a compound contains 4.07%hydrogen,24.27% carbon& 71.65%chlorine.Its molar mass is 98.96g. What are its empirical & molecular formulas
Answer» a compound contains 4.07%hydrogen,24.27% carbon& 71.65%chlorine.Its molar mass is 98.96g. What are its empirical & molecular formulas

Discussion

7061.	What will be the mass of carbon dioxide made from 146C?
Answer» What will be the mass of carbon dioxide made from $_{6}^{14} C$ ?

Discussion

7062.	20g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8g of magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample??
Answer» 20g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8g of magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample??

Discussion

7063.	Which of the statements about the reaction below are incorrect? 2PbO + C - 2Pb + CO2 1. Lead is getting reduced. 2. Carbon of the oxide is getting oxidised. 3. Carbon is getting oxidised. 4. Lead oxide is getting reduced. i. Both 1 and 2 ii. Both 1 and 3 iii. 1, 2 and 3 iv. All
Answer» Which of the statements about the reaction below are incorrect? 2PbO + C - 2Pb + CO2 1. Lead is getting reduced. 2. Carbon of the oxide is getting oxidised. 3. Carbon is getting oxidised. 4. Lead oxide is getting reduced. i. Both 1 and 2 ii. Both 1 and 3 iii. 1, 2 and 3 iv. All

Discussion

7064.	(a) (i) What volume of oxygen is required to burn completely 90dm3 of butane under similar conditions of temperature and pressure? 2C4H10+13O2→8CO2+10H2O (ii) the vapour density of a gas is 8. What would be the volume occupied by 24.0 g of the gas at STP? (iii) A vessel contains X number of molecules of hydrogen gas at a certain temperature and pressure. How many molecules of nitrogen gas would be present in the same vessel under the same conditions of temperature and pressure? (b) O2 is evolved by heating KClO3 using MnO2 as a catalyst. 2KClO3MnO2−−−−→2KCl+3O2 (i) Calculate the mass of KClO3 required to produce 6.72 litres of O2 at STP. [atomic masses of K=39,Cl=35.5,O=16] (ii) Calculate the number of moles of oxygen present in the above volume and also the number of molecules. (iii) Calculate the volume occupied by 0.01 mole of Co2 at STP.
Answer» (a) (i) What volume of oxygen is required to burn completely $90 d m^{3}$ of butane under similar conditions of temperature and pressure? $2 C_{4} H_{10} + 13 O_{2} \to 8 C O_{2} + 10 H_{2} O$ (ii) the vapour density of a gas is 8. What would be the volume occupied by 24.0 g of the gas at STP? (iii) A vessel contains X number of molecules of hydrogen gas at a certain temperature and pressure. How many molecules of nitrogen gas would be present in the same vessel under the same conditions of temperature and pressure? (b) $O_{2}$ is evolved by heating $K C l O_{3}$ using $M n O_{2}$ as a catalyst. $2 K C l O_{3} M n O_{2} - --- \to 2 K C l + 3 O_{2}$ (i) Calculate the mass of $K C l O_{3}$ required to produce 6.72 litres of $O_{2}$ at STP. [atomic masses of $K = 39, C l = 35.5, O = 16]$ (ii) Calculate the number of moles of oxygen present in the above volume and also the number of molecules. (iii) Calculate the volume occupied by 0.01 mole of $C o_{2}$ at STP.

7064.

(a) (i) What volume of oxygen is required to burn completely 90dm3 of butane under similar conditions of temperature and pressure? 2C4H10+13O2→8CO2+10H2O (ii) the vapour density of a gas is 8. What would be the volume occupied by 24.0 g of the gas at STP? (iii) A vessel contains X number of molecules of hydrogen gas at a certain temperature and pressure. How many molecules of nitrogen gas would be present in the same vessel under the same conditions of temperature and pressure? (b) O2 is evolved by heating KClO3 using MnO2 as a catalyst. 2KClO3MnO2−−−−→2KCl+3O2 (i) Calculate the mass of KClO3 required to produce 6.72 litres of O2 at STP. [atomic masses of K=39,Cl=35.5,O=16] (ii) Calculate the number of moles of oxygen present in the above volume and also the number of molecules. (iii) Calculate the volume occupied by 0.01 mole of Co2 at STP.

Answer»

(a) (i) What volume of oxygen is required to burn completely $90 d m^{3}$ of butane under similar conditions of temperature and pressure?

$2 C_{4} H_{10} + 13 O_{2} \to 8 C O_{2} + 10 H_{2} O$

(ii) the vapour density of a gas is 8. What would be the volume occupied by 24.0 g of the gas at STP?
(iii) A vessel contains X number of molecules of hydrogen gas at a certain temperature and pressure. How many molecules of nitrogen gas would be present in the same vessel under the same conditions of temperature and pressure?

(b) $O_{2}$ is evolved by heating $K C l O_{3}$ using $M n O_{2}$ as a catalyst.

$2 K C l O_{3} M n O_{2} - --- \to 2 K C l + 3 O_{2}$

(i) Calculate the mass of $K C l O_{3}$ required to produce 6.72 litres of $O_{2}$ at STP.
[atomic masses of $K = 39, C l = 35.5, O = 16]$
(ii) Calculate the number of moles of oxygen present in the above volume and also the number of molecules.
(iii) Calculate the volume occupied by 0.01 mole of $C o_{2}$ at STP.

Discussion

7065.	Hydrochloric acid is used to purify
Answer» Hydrochloric acid is used to purify

Discussion

7066.	A mixture of 1.65×10^21 molecules of X and 1.85×10^21 molecules of Y weighs 0.688g . The mol.wt. of X is ??(assume mol.wt. of Y is 187)
Answer» A mixture of 1.65×10^21 molecules of X and 1.85×10^21 molecules of Y weighs 0.688g . The mol.wt. of X is ??(assume mol.wt. of Y is 187)

Discussion

7067.	3. 0.9 gram aluminium reacts with dilute HCl to give H2. the volume of H2 evolved at STP is
Answer» 3. 0.9 gram aluminium reacts with dilute HCl to give H2. the volume of H2 evolved at STP is

Discussion

7068.	IF A,B are non-empty sets,then (A-B)U(B-A)=
Answer» IF A,B are non-empty sets,then (A-B)U(B-A)=

Discussion

7069.	The correct order of the tendency of metals in the activity series to reduce water is:
Answer» The correct order of the tendency of metals in the activity series to reduce water is:

Discussion

7070.	Which of the following metals are available in free or native state?
Answer» Which of the following metals are available in free or native state?

Discussion

7071.	polar form of z= 3+root3i/1-i is
Answer» polar form of z= 3+root3i/1-i is

Discussion

7072.	Fill in the blank with a number which balances the following reaction. 3Fe+4H2O→Fe3O4+yH2 Then, y = ___
Answer» Fill in the blank with a number which balances the following reaction. $3 F e + 4 H_{2} O \to F e_{3} O_{4} + y H_{2}$ Then, y = ___

7072.

Fill in the blank with a number which balances the following reaction. 3Fe+4H2O→Fe3O4+yH2 Then, y = ___

Answer» Fill in the blank with a number which balances the following reaction.

$3 F e + 4 H_{2} O \to F e_{3} O_{4} + y H_{2}$

Then, y = ___

Discussion

7073.	Can we call a gangue a mineral or ore or both or gangue is different from both.
Answer» Can we call a gangue a mineral or ore or both or gangue is different from both.

Discussion

7074.	How many litre of water will a cuboidal tank contain if its lenght, breadth and height are 50 cm, 40 cm and 20 cm respentively?
Answer» How many litre of water will a cuboidal tank contain if its lenght, breadth and height are 50 cm, 40 cm and 20 cm respentively?

Discussion

7075.	During the decomposition of Hydrogen peroxide, the presence of manganese dioxide has increased the rate of the reaction. In this case the manganese dioxide acts as a ___.
Answer» During the decomposition of Hydrogen peroxide, the presence of manganese dioxide has increased the rate of the reaction. In this case the manganese dioxide acts as a ___.

Discussion

7076.	nta first order reaction is 50% completed in 20 minutes at 27 degree celcius and in 10 minutes at 47 degree celcius.what is the energy of activation of the reaction?n
Answer» nta first order reaction is 50% completed in 20 minutes at 27 degree celcius and in 10 minutes at 47 degree celcius.what is the energy of activation of the reaction?n

Discussion

7077.	Distinguish between liquid ammonia and liquor ammonia fortis.
Answer» Distinguish between liquid ammonia and liquor ammonia fortis.

Discussion

7078.	The compound which can not act as reducing agent is 1)NH3 2)HNO3 3)NO2 4)HNO2
Answer» The compound which can not act as reducing agent is 1)NH3 2)HNO3 3)NO2 4)HNO2

Discussion

7079.	An acidified solution of potassium chromate was layered with an equal volume of amyl alcohol. When it was shaken after the addition of 1 mL of 3% H2O2. a blue alcohol layer was obtained. The blue color is due to the formation of a chromium (VI) compound 'X'. What is the number of oxygen atoms bonded to chromium through only single bonds in a molecule of X?
Answer» An acidified solution of potassium chromate was layered with an equal volume of amyl alcohol. When it was shaken after the addition of 1 mL of 3% $H_{2} O_{2}$ . a blue alcohol layer was obtained. The blue color is due to the formation of a chromium (VI) compound 'X'. What is the number of oxygen atoms bonded to chromium through only single bonds in a molecule of X?

Discussion

7080.	39. On heating ammonium dichromate, the gas evolved is:- 1)O2 2)N2 3)N2O 4)NH3
Answer» 39. On heating ammonium dichromate, the gas evolved is:- 1)O2 2)N2 3)N2O 4)NH3

Discussion

7081.	Why is Al(OH)2 is not alkali at room temperature.
Answer» Why is Al(OH)2 is not alkali at room temperature.

Discussion

7082.	Which organic compound is indicated by marsh gas and fire damp?
Answer» Which organic compound is indicated by marsh gas and fire damp?

Discussion

7083.	While diluting concentrated sulphuric acid, the acid should be added to water and not water to the acid. Explain why? [3 MARKS]
Answer» While diluting concentrated sulphuric acid, the acid should be added to water and not water to the acid. Explain why? [3 MARKS]

Discussion

7084.	Calcium carbide is used for the artificial ripening of fruits. Actually, the fruit ripens because of the heat evolved while calcium carbide reacts with moisture. During the reaction, calcium hydroxide and acetylene gas is formed. If 200 cm3 of acetylene is formed from a certain mass of calcium carbide. Find the volume of oxygen required and carbon dioxide formed during the complete combustion. The combustion reaction can be represented as below: 2C2H2(g)+5O2(g)→4CO2(g)+2H2O(g)
Answer» Calcium carbide is used for the artificial ripening of fruits. Actually, the fruit ripens because of the heat evolved while calcium carbide reacts with moisture. During the reaction, calcium hydroxide and acetylene gas is formed. If 200 $c m^{3}$ of acetylene is formed from a certain mass of calcium carbide. Find the volume of oxygen required and carbon dioxide formed during the complete combustion. The combustion reaction can be represented as below: $2 C_{2} H_{2} (g) + 5 O_{2} (g) \to 4 C O_{2} (g) + 2 H_{2} O (g)$

7084.

Calcium carbide is used for the artificial ripening of fruits. Actually, the fruit ripens because of the heat evolved while calcium carbide reacts with moisture. During the reaction, calcium hydroxide and acetylene gas is formed. If 200 cm3 of acetylene is formed from a certain mass of calcium carbide. Find the volume of oxygen required and carbon dioxide formed during the complete combustion. The combustion reaction can be represented as below: 2C2H2(g)+5O2(g)→4CO2(g)+2H2O(g)

Answer»

Calcium carbide is used for the artificial ripening of fruits. Actually, the fruit ripens because of the heat evolved while calcium carbide reacts with moisture. During the reaction, calcium hydroxide and acetylene gas is formed.

If 200 $c m^{3}$ of acetylene is formed from a certain mass of calcium carbide. Find the volume of oxygen required and carbon dioxide formed during the complete combustion. The combustion reaction can be represented as below:

$2 C_{2} H_{2} (g) + 5 O_{2} (g) \to 4 C O_{2} (g) + 2 H_{2} O (g)$

Discussion

7085.	(a) How does the electropositive character of elements change on going down in a group of the periodic table? (b) State how the valency of elements varies (i) in a group, and (ii) in a period, of the periodic table.
Answer» (a) How does the electropositive character of elements change on going down in a group of the periodic table? (b) State how the valency of elements varies (i) in a group, and (ii) in a period, of the periodic table.

7085.

(a) How does the electropositive character of elements change on going down in a group of the periodic table? (b) State how the valency of elements varies (i) in a group, and (ii) in a period, of the periodic table.

Answer»

(a) How does the electropositive character of elements change on going down in a group of the periodic table?

(b) State how the valency of elements varies (i) in a group, and (ii) in a period, of the periodic table.

Discussion

7086.	What is the difference between series and periods in mendeleev periodic table? Does both of these are same or series are called sub-periods?
Answer» What is the difference between series and periods in mendeleev periodic table? Does both of these are same or series are called sub-periods?

Discussion

7087.	What is the correct formula of sulphuric acid?
Answer» What is the correct formula of sulphuric acid?

Discussion

7088.	A gaseous mixture contains nitrogen and oxygen in the ratio of 4 : 1 by weight. Therefore, the ratio of their number of molecules is:
Answer» A gaseous mixture contains nitrogen and oxygen in the ratio of 4 : 1 by weight. Therefore, the ratio of their number of molecules is:

Discussion

7089.

(d) Match the following: Column A Column B (i) A substance that turns moist starch iodide paper blue. Ferrous sulphate (ii) A compound which releases a reddish brown gas on reaction with concentrated sulphuric acid and copper turnings. Chlorine (iii) A solution of this compound gives a dirty green precipitate with sodium hydroxide. Copper nitrate (iv) A compound which on heating with sodium hydroxide produces a gas which forms dense white fumes with hydrogen chloride. Lead carbonate (v) A white solid which gives a yellow residue on heating. Ammonium sulphate

Answer» (d) Match the following:

	Column A	Column B
(i)	A substance that turns moist starch iodide paper blue.	Ferrous sulphate
(ii)	A compound which releases a reddish brown gas on reaction with concentrated sulphuric acid and copper turnings.	Chlorine
(iii)	A solution of this compound gives a dirty green precipitate with sodium hydroxide.	Copper nitrate
(iv)	A compound which on heating with sodium hydroxide produces a gas which forms dense white fumes with hydrogen chloride.	Lead carbonate
(v)	A white solid which gives a yellow residue on heating.	Ammonium sulphate

Discussion

7090.	Which of the following factors don't affect the process of electrolysis? Ans: ___ Concentration of the electrolyte Galvanometer Size of the electrode Nature of the metal used Current Voltage
Answer» Which of the following factors don't affect the process of electrolysis? Ans: ___ Concentration of the electrolyte Galvanometer Size of the electrode Nature of the metal used Current Voltage

7090.

Which of the following factors don't affect the process of electrolysis? Ans: ___ Concentration of the electrolyte Galvanometer Size of the electrode Nature of the metal used Current Voltage

Answer»

Which of the following factors don't affect the process of electrolysis?
Ans: ___

Concentration of the electrolyte
Galvanometer
Size of the electrode
Nature of the metal used
Current
Voltage

Discussion

7091.	Q) A compound contains 42.39% K, 15.2% Fe, 19.56% C and 22.8% N. The molecular mass of the compound is 368 u. Find the molecular formula of the compound.
Answer» Q) A compound contains 42.39% K, 15.2% Fe, 19.56% C and 22.8% N. The molecular mass of the compound is 368 u. Find the molecular formula of the compound.

Discussion

7092.	if pKw of water is obtained 13.48 on increasing the temperature then H^+ ion concentration in water will be
Answer» if pKw of water is obtained 13.48 on increasing the temperature then H^+ ion concentration in water will be

Discussion

7093.	For every substitution reactions on Benzene, is the decreasing order of abundance of the formed product in the order : Ortho > Meta > Para ?
Answer» For every substitution reactions on Benzene, is the decreasing order of abundance of the formed product in the order : Ortho > Meta > Para ?

Discussion

7094.	solution of which salt in water is acidic;- a. Zn(OH)CL b , NaHCO3 C. FeCL3 d, NaHSO4
Answer» solution of which salt in water is acidic;- a. Zn(OH)CL b , NaHCO3 C. FeCL3 d, NaHSO4

Discussion

7095.	41. If average molecular mass of air is 29 ,than assuming that n2 and o2 are there ,calculate mile percent of n2 mass percent of n2
Answer» 41. If average molecular mass of air is 29 ,than assuming that n2 and o2 are there ,calculate mile percent of n2 mass percent of n2

Discussion

7096.	(a) How is nitric acid prepared in laboratory?(b) What is the purpose of conc. H2SO4 in the above preparation?(c) Why is the temperature maintained at 200°C in the above reaction?(d) Can we use conc. HCl in place of conc. H2SO4?
Answer» (a) How is nitric acid prepared in laboratory? (b) What is the purpose of conc. H₂SO₄ in the above preparation? (c) Why is the temperature maintained at 200°C in the above reaction? (d) Can we use conc. HCl in place of conc. H₂SO₄?

Discussion

7097.	The equivalent mass of As_2S_3 in the following reaction As_2S_3+NaClO_3+NaOH→ Na_3AsO_4+NaClO+Na_2SO_4, is (assuming molar mass of As_2S_3 is M) (1) M/16 (2) M/4 (3) M/20 (4) M/28
Answer» The equivalent mass of As_2S_3 in the following reaction As_2S_3+NaClO_3+NaOH→ Na_3AsO_4+NaClO+Na_2SO_4, is (assuming molar mass of As_2S_3 is M) (1) M/16 (2) M/4 (3) M/20 (4) M/28

Discussion

7098.	A compound X formed after heating coke with lime react with water to give Y which on passing over red-hot iron at 873 produces Z. The compound Z is
Answer» A compound X formed after heating coke with lime react with water to give Y which on passing over red-hot iron at 873 produces Z. The compound Z is

Discussion

7099.	GIVE IUPAC NAMING OF FOLLLOWING COMPUNDS : 1) CH3-CH(OH)-CH2-CH3 2) CH3-CH2-CH(OH)-CH2-CHO 3)CH3-CH2-CH(CH3)-CH(OH)-CH3
Answer» GIVE IUPAC NAMING OF FOLLLOWING COMPUNDS : 1) CH3-CH(OH)-CH2-CH3 2) CH3-CH2-CH(OH)-CH2-CHO 3)CH3-CH2-CH(CH3)-CH(OH)-CH3

Discussion

7100.	50. The vapour presssure of pure liquid. A and B are 300 and 500 mm Hg respectively at 273 k. the mole fraction of liquid A in the mixture will be if total vapour pressure is 450 mm of HG
Answer» 50. The vapour presssure of pure liquid. A and B are 300 and 500 mm Hg respectively at 273 k. the mole fraction of liquid A in the mixture will be if total vapour pressure is 450 mm of HG

Discussion

Explore topic-wise InterviewSolutions in .

General electronic configuration of lanthanides is

Write balanced equations to show the preparation of the following:(i) ethane from sodium propionate(ii) ethene from ethanol(iii) ethyne from calcium carbide(iv) ethanoic acid from ethane

Why should an equation be balanced? Explain with the help of a simple equation.

Name the metal of the filament of an electric current

In a fiven reaction, barium hydroxide reacts with ammonium chloride to from product X and Y. identify X and Y. Ba(OH)2 + NH4CI → X + Y

If for an element (X), the values of successive ionization energies I1, I2, I3, I4 and I5 are 800, 2427, 3658, 25024, 32824 kJ mol−1 respectively, then the number of valence electrons present are:

The strength of an acid depends on its tendency to:

I just wanted to know whether E0 value for Rubidium is more of Caesium

Which ahs stronger dπ- pπ bonding?Options PO4 3-, SO4 2-, SiO4 4-, ClO4-

a compound contains 4.07%hydrogen,24.27% carbon& 71.65%chlorine.Its molar mass is 98.96g. What are its empirical & molecular formulas

What will be the mass of carbon dioxide made from 146C?

20g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8g of magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample??

Which of the statements about the reaction below are incorrect? 2PbO + C - 2Pb + CO2 1. Lead is getting reduced. 2. Carbon of the oxide is getting oxidised. 3. Carbon is getting oxidised. 4. Lead oxide is getting reduced. i. Both 1 and 2 ii. Both 1 and 3 iii. 1, 2 and 3 iv. All

Hydrochloric acid is used to purify

A mixture of 1.65×10^21 molecules of X and 1.85×10^21 molecules of Y weighs 0.688g . The mol.wt. of X is ??(assume mol.wt. of Y is 187)

3. 0.9 gram aluminium reacts with dilute HCl to give H2. the volume of H2 evolved at STP is

IF A,B are non-empty sets,then (A-B)U(B-A)=

The correct order of the tendency of metals in the activity series to reduce water is:

Which of the following metals are available in free or native state?

polar form of z= 3+root3i/1-i is

Fill in the blank with a number which balances the following reaction. 3Fe+4H2O→Fe3O4+yH2 Then, y = ___

Can we call a gangue a mineral or ore or both or gangue is different from both.

How many litre of water will a cuboidal tank contain if its lenght, breadth and height are 50 cm, 40 cm and 20 cm respentively?

During the decomposition of Hydrogen peroxide, the presence of manganese dioxide has increased the rate of the reaction. In this case the manganese dioxide acts as a ___.

nta first order reaction is 50% completed in 20 minutes at 27 degree celcius and in 10 minutes at 47 degree celcius.what is the energy of activation of the reaction?n

Distinguish between liquid ammonia and liquor ammonia fortis.

The compound which can not act as reducing agent is 1)NH3 2)HNO3 3)NO2 4)HNO2

39. On heating ammonium dichromate, the gas evolved is:- 1)O2 2)N2 3)N2O 4)NH3

Why is Al(OH)2 is not alkali at room temperature.

Which organic compound is indicated by marsh gas and fire damp?

While diluting concentrated sulphuric acid, the acid should be added to water and not water to the acid. Explain why? [3 MARKS]

(a) How does the electropositive character of elements change on going down in a group of the periodic table? (b) State how the valency of elements varies (i) in a group, and (ii) in a period, of the periodic table.

What is the difference between series and periods in mendeleev periodic table? Does both of these are same or series are called sub-periods?

What is the correct formula of sulphuric acid?

A gaseous mixture contains nitrogen and oxygen in the ratio of 4 : 1 by weight. Therefore, the ratio of their number of molecules is:

Which of the following factors don't affect the process of electrolysis? Ans: ___ Concentration of the electrolyte Galvanometer Size of the electrode Nature of the metal used Current Voltage

Q) A compound contains 42.39% K, 15.2% Fe, 19.56% C and 22.8% N. The molecular mass of the compound is 368 u. Find the molecular formula of the compound.

if pKw of water is obtained 13.48 on increasing the temperature then H^+ ion concentration in water will be

For every substitution reactions on Benzene, is the decreasing order of abundance of the formed product in the order : Ortho > Meta > Para ?

solution of which salt in water is acidic;- a. Zn(OH)CL b , NaHCO3 C. FeCL3 d, NaHSO4

41. If average molecular mass of air is 29 ,than assuming that n2 and o2 are there ,calculate mile percent of n2 mass percent of n2

(a) How is nitric acid prepared in laboratory?(b) What is the purpose of conc. H2SO4 in the above preparation?(c) Why is the temperature maintained at 200°C in the above reaction?(d) Can we use conc. HCl in place of conc. H2SO4?

The equivalent mass of As_2S_3 in the following reaction As_2S_3+NaClO_3+NaOH→ Na_3AsO_4+NaClO+Na_2SO_4, is (assuming molar mass of As_2S_3 is M) (1) M/16 (2) M/4 (3) M/20 (4) M/28

A compound X formed after heating coke with lime react with water to give Y which on passing over red-hot iron at 873 produces Z. The compound Z is

GIVE IUPAC NAMING OF FOLLLOWING COMPUNDS : 1) CH3-CH(OH)-CH2-CH3 2) CH3-CH2-CH(OH)-CH2-CHO 3)CH3-CH2-CH(CH3)-CH(OH)-CH3

50. The vapour presssure of pure liquid. A and B are 300 and 500 mm Hg respectively at 273 k. the mole fraction of liquid A in the mixture will be if total vapour pressure is 450 mm of HG