2599 + Interview Questions in Chemistry in Class 9 Page 30 InterviewSolution

1451.	If one mole of oxygen atom weigh 16 g, find the mass of one atom of oxygen in grams.
Answer» SOLUTION :The weight of 1 mole of oxygen atom = 16 G 1 mole of oxygen atom = `6.022 xx 10^(23)` ATOMS `:.` mass of 1 atom of oxygen = `(16)/(6.022 xx 10^(23))` `= 2.66 xx 10^(-23)`

Discussion

1452.	If one mole of nitrogen pentoxide undergoes thermal decomposition to form oxides of nitrogen and oxygen, explain how rate of formation of products is related to rate of consumption of reactants.
Answer» Solution :(i) balanced CHEMICAL equation (II) Relation between RATES of reaction of REACTANTS and products from balanced chemical equation.

Discussion

1453.	If one mole of carbon atoms weighs 12 grams, what is the mass (in grams) of 1 atom of carbon?
Answer» SOLUTION :`1.99 XX 10^(-23)` G

Discussion

1454.	If one mole of carbon atoms weigh 12 grams, what is the mass (in grams) of one atom of carbon ?
Answer» SOLUTION :1 mole of carbon atoms = `6.022 xx 10^(23)` atoms. `:. 6.022 xx 10^(23)` atoms of carbon WEIGH 12g `:.` ONE atom of carbon weighs `(12)/(6.022 xx 10^(23)) G = 1.99 xx 10^(-23) g`

Discussion

1455.	If one mole of carbon atoms weight 12 gms what is the mass (in gms ) of 1 atom of carbon .
Answer» Solution :One MOLE of carbon ATOMS weighs 12 g i.e. mass of 1 mole of carbon atoms = 12g Then mass of `6.022 x 10^(23)` NUMBER of carbon atom-12 g. `( :. 6.022xx10^(23)` is avagadro CONSTANT ) herefore mass of 1 atom of carbon -`12-: (6.022x 10^(23)) ` `= 1.992x 10^(23)g`

Discussion

1456.	If number of electron in an atom is 8 and number of proton is also 8, then (i) what is the atomic numberof the atom and (ii) what is the charge on the atom ?
Answer» SOLUTION :(i) The atomic number is equal to the number of PROTONS. Therefore, the atomic number of the atom is 8. (ii) Since the number of both ELECTRONS and protons is equal, therefore, the charge on the atoms is O. (neutral).

Discussion

1457.	If K_(C ) for the formation of ammonia is 2 " moles"^(-2) "lt"^(2), K_(c ) for decomposition of ammonia is ____.
Answer» ANSWER :`0.5 " MOLES"^(2)//L^(2)`

Discussion

1458.	If K and L shells of an atom are full, then what would be the total number of electrons in the atom ?
Answer» Solution :K SHELL can accommodate MAXIMUM 2 ELECTRONS. L shell can accommodate maximum 8 electrons. Both the SHELLS are full. `therefore ` the total number of electrons in the atom = 2 + 8 = 10 .

Discussion

1459.	If K and L shells of an atom are full then what would be the total number of electrons in the atom ?
Answer» SOLUTION :The maximum CAPACITY of K shell is 2 electrons and L - shell can accommodate maximum 8 electrons in it. Therefore, there will be TEN electrons in the ATOM.

Discussion

1460.	If iron atom is available in the form of , say three isotopes ""_(25)^(54)"Fe", ""_(26)^(56)Fe and " "_(26)^(57)Fe and their proportion is 5% , 90% and 5% respectively. Calculate the average mass of iron atom.
Answer» SOLUTION :The AVERAGE atomlc mass of IRON `= (am + bn + cz)/((m + N + z))` = `(54 xx 5 + 56 xx 90 + 57 xx 5)/(5 + 90 + 5 ) ` `= (270 + 5040 + 285 )/(100)` = `(5595)/(100)` = ` 55.95` u

Discussion

1461.	If I_(1) is the first ionisation potiential I_(2) is the second ionsation potential I_(3) is the thirs ionsiation potentialand I_(4) is the fourth ionisation potential of anelement then which of the following has the laest value?
Answer» `I_(1)` `I_(2)` `I_(3)` `I_(4)` SOLUTION :Ionisation potential VALUES increase in the following order `11lt12lt14lt….`

Discussion

1462.	If Dobereiner is related with 'law of triads', then Newlands is related with
Answer» Modern periodic LAW HUND's rule Law of OCTAVES Pauli's Exclusion principle Answer :C

Discussion

1463.	If dispersing medium is liquid and dispersed phase is gas, then what is this type of colloid called ?
Answer» Jelly Foam Aerosol Emulsion Answer :A

Discussion

1464.	If cold water is poured on flask containing very hot distilled water and water vapour, thewater inside the flask started to boil below 100^(@)C. The principle involved is __________.
Answer» SOLUTION :decreasingpressure DECREASES the BOILINGPOINT

Discussion

1465.	If canal ray experiments are conducted with different isotopes of hydrogen gas, do the canal rays produced show that same deflection under the external eletric field? Give reasons to support your answer.
Answer» Solution :Portium `(._1H^1)` deuterium `(._1H^2)` and tritium `(._1H^3)` are NATURALLY occuring isotopes of hydrogen. UNIPOSITIVE ions of protium, deuterium and tritium differ in their mass. Thus their e/mratio is DIFFERENT. Therefore, they defelct at different angles in an EXTERNAL electric FIELD.

Discussion

1466.	If Bromine atom is available in the form of say, two isotopes ._(35)^(79)Br(49.7%) and ._(35)^(81)Br(50.3%) Calculate the average atomic mass of Bromine atom.
Answer» Solution :It is GIVEN that two isotopes of Bromine are 79/35 BR(49.7%) and 81/35 Br(50.3%). Then, the average atomic MASS of Bromine atom is given by `79xx(49.7)/(100)+81xx(50.3)/(100)` `= (3926.3)/(100)+(4074.3)/(100)` `=(8000.6)/(100)` `= 80.006 U`

Discussion

1467.	If bromine atom is available in the form of, say two isotopes""_(35)^(79)Br (49.7%) and ""_(35)^(85)Br (50.3%). Calculate the average atomicmass of bromine atom.
Answer» Solution :The AVERAGE ATOMIC mass of bromine atom = `(79 xx (49.7)/(100) ) + (81 xx (50.3)/(100))` = 39.263 + 40.723 = 80.006 = 80 The average atomic mass of bromine atom Is 80 u.

Discussion

1468.	If an atom contains one electron and one proton, will it carry any charge or not ?
Answer» Solution :An ELECTRON is a NEGATIVELY charged particle. The magnitude of their charges is EQUAL. Therefore, an ATOM containing one electron and one proton will not CARRY any charge. Thus it will be a neutral atom.

Discussion

1469.	If A = 23 and Z = 11 for Na atom, how many protons, electrons and neutrons are present in Na atom ?
Answer» Solution :A = 23, Z = 11 No of `e^(-)` = No of PROTONS = Z Number of electron OUTSIDE NUCLEUS = 11 Number of electron inside nucleus = 11 No of neutrons `= A-Z=23-11=12`

Discussion

1470.	If 6 g of a metal gets deposited by passing 2 amp of current for 2 h 30 min, calculate the equivalent weight of the metal.
Answer» SOLUTION :(i) calculation of the amount of charge required to DEPOSIT the given amount of METAL (ii) calculation of equivalent weight of the metal, based on the amount of charge passed through the ELECTROLYTE (iii) 32.2

Discussion

1471.	If ""^12C is used as standard , the relative mass of an atom of sodium is 23 and the relative mass of an atom of phosphorus is 31 . Find the relative masses of a samples of sodium and phosphorus with respect to each other when each contains 3.0 xx 10^(25) atoms .
Answer» Solution :The relative MASSES of samples that contain equal numbers of ATOMS will be the same as the relative masses of individual atoms , thus , `("mass of the SAMPLE of sodium")/("mass of the sample of phosphorus") = (23)/(31)` .

Discussion

1472.	If 12 g is carbon is burnt in the presence of 32g of oxygen, how much CO_(2) will be formed.
Answer» Solution :GIVEN, the reaction is CARBON +Oxygen `to` Carbondioxide Mass of carbon `=12G` Mass of oxygen =32g Mass of carbondioxide `(Co_(2))=Xg` Since the reaction is in agreement with the LAW of conservation of mass, then then mass of reactants =total mass of products i.e., `12g+32g=x i.e,X=44g` THEREFORE, Mass of carbonadioxide `(CO_(2))` formed =44g

Discussion

1473.	Identity the relation and fill up the blank. Law of electrolysis : _______
Answer» ANSWER :MICHEL FARADAY

Discussion

1474.	Identity the relation and fill up the blank. Law of conservation of mass : ________
Answer» ANSWER :Lavosier

Discussion

1475.	Identity the correct sequence of fraction obtained when petroleum is subjectd to fractional distillation . lubricaing oil petrol petroleum ether diesel oil
Answer» 2341 3241 3214 2431 Solution :(i) petroleum ether (II) petrol (III) diesel oil (IV) LUBRICATING oil

Discussion

1476.	Identify which of the following is homogenous mixture or heterogeneous one. Also identify the type of constituents in mixture (e.g gas in gas, in liquid, gas in solid etc) a. Air b. water and soil (N_(2) + O_(2)) c. Hydrogen in Palladium d. Aerated water (CO_(2) + H_(2)O) e. Chalk in water f. Ethylalcohol in water g. Alloy Eg : brass h. Dust i. Sand + Iron fillings j. Sand + ammonium chloride k. milk l. Mercury in amalgamated Zinc
Answer» Solution :`{:("Types of mixture","Homogenous Mixture","HETEROGENOUS Mixture"),("1. Gas in gas","Air",),("2. Gas in liquid","AERATED water",),("3. Gas in solid","Hydrogen in Palladium",),("4. Liquid in liquid","ETHYL alcohol","water + OIL, milk"),("5. Liquid is solid","Mercury in amalgamatd ZINC",),("6. Solid in liquid","Sugar in water","chalk in water, Dust in water"),("7. Solid in solid","Alloys Eg : Brass","Sand + Iron Fillings, Sand +"),(,,"ammonium chloride"):}`

Discussion

1477.	Identify whether the given substance is mixture or compound and justify your answer.
Answer» SOLUTION :

Discussion

1478.	Identify the solutions among the following mixtures : (a) Soil, (b) Sea water, ( c) Air, (d) Coal and (e) Soda water.
Answer» SOLUTION :(B) SEA water, ( c) AIR and (e) Soda water are solutions.

Discussion

1479.	Identify the solutionsamong the Followingmixtures. (a)Soil (b) Sea water (c ) Air (d) Coal ( e) Soda water?
Answer» SOLUTION :SOLUTIONS :-Water, Sea water, Air,SODAWATER

Discussion

1480.	Identify the oxide which forms the strongest base:
Answer» MGO `AI_(2)O_(3)` `Na_(2)O` `CaO` Answer :C

Discussion

1481.	Identify the mixture which can be separated by magnetic separated bymagnetic separation method.
Answer» chalk POWDER + SAND iron + sand common salt + sand sulphur + sand SOLUTION :Sinceironis magnetic in NATURE iron and sand mixture can be separtedby magneticseparation.

Discussion

1482.	Identify the methods by which the individual components of mixture containing water, potassium nitrate, sodium chloride, alcohol and carbon tetrahedron can be separated.
Answer» separating FUNNEL, fraction distillation, fraction crytallisation, ditillation fractional distillation, distillation, fractional crystallisation separating funnel, fractional distillation, filtration distillation separating funnel, fractional distillation, sedimentation and DECANTATION SOLUTION :Both `KNO_(3)` and NaCl are solubein WATER forminga homogeneoussolution which is solublein alcoholand forminga mixture. THISMIXTURE is insoublein `C Cl_(4)`. Hence , `C Cl_(4)`is separatendby fractionaldistillation . As `KNO_(3)` is moresolublethan NaClin water, thereforeit isseparated by distillation.

Discussion

1483.	Identify the incorrect statement and correct them. a. Like covalent compounds, Coordinate compounds also contain charged particles (ions), so they are good conductors of electricity b. Tonic bond is a weak bond when compared to Hydrogen bond. c. Ionic or electrovalent bonds are formed by mutual sharing of electrons between stoms. d. Loss of electrons is called Oxidation and Gain of electron is called Reduction. e. The electrons which are not involved in bonding are called venlence electrons.
Answer» Solution :a. Like covalent compounds, coordinate compounds also do not contain charged particles (ions), so they are bad conductors of electricity. b. An IONIC bond is formed by the electrostatic attraction between positive and negative ions. Hence it is stronger than Hydrogen bonding which is formed by electronegativity. c. The ionic bond is formed between two ATOMS when ONE or more ELECTRONS are transferred from the valence shell of one atom to the valence shell of the other atom. The atom that loses electrons will form a cation (positive ion) and the atom that gains electrons will form an ANION (negative ion). d. Loss of electrons is called Oxidation and Gain of electron is called Reduction. e. The electrons which are involved in bonding are called valence electrons.

Discussion

1484.	Identify the following reactions as oxidation or reduction (a). Na to Na^(+)+ e^(-) (b) Fe^(3+)+ 2e^(-) to Fe^(+)
Answer» Solution :It is an Oxidation REACTION. (a) Oxidation A CHEMICAL reaction which involves addition of OXYGEN or removal of hydrogen or loss of electrons is CALLED oxidation. b. It is a Reduction reaction. Reduction: A chemical reaction which involves addition of hydrogen or removal of oxygen or gain of electrons is called reduction

Discussion

1485.	Identify the compounds as Ionic Covalent/Coordinate based on thegiven characteristics.
Answer» SOLUTION :a. Soluble in non polar SOLVENTS b. undergoes FASTED instantaneous REACTIONS c. Non conductors of electricity c Solids at room temperature a. Covalent COMPOUNDS b. Ionic compounds. c. Covalent compounds d. Ionic compounds

Discussion

1486.	Identify the colloids from the following : Soda water, milk, sponge, clouds, mixture of alcohol and water, jelly.
Answer» SOLUTION :COLLOIDS : SODA water, MILK, sponge, clouds, JELLY.

Discussion

1487.	Identify colloids from the following :Copper sulphate solution, milk, smoke, muddy water, butter, sugar solution, face cream, lemonade.
Answer» Solution :COLLOIDS : milk, SMOKE, MUDDY water, BUTTER, face cream, lemonade.

Discussion

1488.	Ice , water and vapour are ................ the same .
Answer» ANSWER :CHEMICALLY

Discussion

1489.	Ice floats on the surface of water because
Answer» it is HEAVIER than WATER the density of water is same as that of ICE ice is lighter than water none of these Answer :C

Discussion

1490.	Ice floats on water because thedensity of ice is……..than that of water.
Answer» ANSWER :LESS

Discussion

1491.	(i) Pressure cooker reduces the cooking time. Explain the priciple involved. (ii) Fish and meat can be preserved for a longer time in ice if common salt is added to it. Give reason. (iii) When a glass of ise and cold water is kept open at room temperature, what observation is found ? Give reason.
Answer» Solution :(i) In a pressure cooker, water is subjected to heating in a closed vessel in a confirmed space. The steam generatedin fixed volume increases the pressure beyond the normal ATMOSPHERIC pressure. SINCE the external pressure is more, the boiling point of water rises beyond `100^(@)` C. The temperature of cooking medium being greater than the normal boiling point, therefore, food gets cooked at a faster rate, and thus, saving time and fuel. (II) Addition of common salt tpo ICE reduces the freezing point of ice to below `0^(@)`C. A mixture of three parts of ice and one part of common salt called freezing mixture can produce a muchlower temperature `(-21^(@)`C`)`.Thus, fish and meat can be prevented from spoilage for a longer time in time freezing mixture. (iii) When a glass of water is kept atr room temperature, water droplets are observedon the outer walls of glass. This is because the water vapour present in air when comes in contact with glass containing ice COLD water vapour present in air gets condensed.

Discussion

1492.	(a) What is fractional distillation ? What is the use of fractionating column in fractional distillation? (b) Draw a labelled diagram of the fractional distillation apparatus distillation apparatus used for separating a mixture of alcohol and water
Answer» Solution : (b) A fractionating column obstructs the upwards movement of the vapours of the liquids. As a result, the ENERGY (latent heat of condensation) which is released by the high boiling liquid is taken by the LOW boiling liquid. It remains in the vapour state. The high boiling liquid by releasing energy CONDENSES and falls back in the distillation flask. Thus, fractionating column helps in the separation of the COMPONENTS from a liquid mixture. For example, a mixture of ethyl alcohol and water.

Discussion

1493.	(i) Diamond is a better conductor of heat than copper and silver. Give appropritate reasons. (ii) Graphite is a good conductor of electricity . Justify the statement.
Answer» Solution :(i) DIAMOND crystals have a very regualr arrangment. The forces binding the atoms togather are strong and the atoms are close to each other. Hence, they can easily transfer vibratory motion from one ATOM to the next. In metals, free electrons are there which hinder the transfer of birbation of the metals atoms to some extent. But in diamond there are no free electrons. Hence, it is a very good conductor of heat. (ii) Each carbon atom in graphite is inturn attached to other three carbon atoms FORMING a planar structure. MANY such planar rings attach themselves to from hexagonal layered structure. Since every carbon is attached to three other carbon atoms , one electron is left BEHIND which is responsible for the conductivity. thus , due to the presence of free electrons , graphite is a good conductor of electricity.

Discussion

1494.	(i) Calculate the weight of aluminium deposited during the electrolysis of molten aluminium chloride by passing 193 amp of current for 500 min.
Answer» Solution :`A1^(+3) + 3E^(-) to AL` Mass of Al deposited `(W) = (Mct)/(ZF)` M = molecular weight = 27 c = 193 amp `t = 500 xx 60 s` Z = 3 `F = 96,500 C` `W = (27 xx 193 xx 500 xx 60)/(3 xx 96500) = 540 g`

Discussion

1495.	(i) Calculate molar mass of Al(OH)_(3). (Al = 27 u, O = 16 u, H = 14) (ii) Write chemical formulae of ammonium carbonate and magnesium chloride. (iii) Write the difference between atom and molecule.
Answer» Solution :(i) Molar mass of `Al(OH)_(3)` `= 27 + 3 [1 xx 16 + 3(1)]` = 27 + 3(16 + 3) = 27 + 3(19) = 27 + 57 = 84 G (ii) Ammonium carbonate : `(NH_(4))_(2)CO_(3)` Magnesium chloride : `MgCl_(2` (iii) An atom is the SMALLEST particle of an ELEMENT which may or may not have independent existence. A molecule is the smallest particle of an element or a COMPOUND which have independent existence.

Discussion

1496.	(i) Account for the changes observed in the surroundings when carbon dioxide gas comes out of a fire extinguisher. (ii) Althoguh CO_2 is generally used a material in fire extinguisher it cannot be used toput out fires casued by metals like Na. Mg and K.
Answer» Solution :(a) Carbon dioxide comes out with great force through a small nozzle form soda acid fire extinguisher. Sudden expansion of `CO_2` takes place which leads to reduction in temperature of the carbon dioxide to a great EXTENT and moisture present in AIR condenses on the carbon dioxide moleucles and appears like fog. (b) Na, MGAND K metals continue to BURN in atomsphere of `CO_2` . it is due to fact that these active metals GET oxidised by `CO_2` to form respective oxides.

Discussion

1497.	Hydrogen sulphide on reacting with aqueous solution of metal salts converts them to ___________________.
Answer» SOLUTION :N/A

Discussion

1498.	Hydrogen has...... Isotopes. Two, three, four)
Answer» ANSWER :THREE

Discussion

1499.	Hydrogen gas kept in a vessel spreads throughout the spaceof the vessel .
Answer» ANSWER :T

Discussion

1500.	Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?
Answer» Solution :HYDROGEN and oxygen combine in the ratio 1:8 by mass to FORM water. Let XG of oxygen gas is required. `"Hydrogen" : "Oxygen" to H_(2)O` 1:8= 3:x `:. (1)/(8)=(3)/(x)` `x = 3 xx 8"":. x = 24 g` `:.` 24 g of oxygen gas would be required to react completely with 3g of hydrogen gas.

Discussion

Explore topic-wise InterviewSolutions in .

If one mole of oxygen atom weigh 16 g, find the mass of one atom of oxygen in grams.

If one mole of nitrogen pentoxide undergoes thermal decomposition to form oxides of nitrogen and oxygen, explain how rate of formation of products is related to rate of consumption of reactants.

If one mole of carbon atoms weighs 12 grams, what is the mass (in grams) of 1 atom of carbon?

If one mole of carbon atoms weigh 12 grams, what is the mass (in grams) of one atom of carbon ?

If one mole of carbon atoms weight 12 gms what is the mass (in gms ) of 1 atom of carbon .

If number of electron in an atom is 8 and number of proton is also 8, then (i) what is the atomic numberof the atom and (ii) what is the charge on the atom ?

If K_(C ) for the formation of ammonia is 2 " moles"^(-2) "lt"^(2), K_(c ) for decomposition of ammonia is ____.

If K and L shells of an atom are full, then what would be the total number of electrons in the atom ?

If K and L shells of an atom are full then what would be the total number of electrons in the atom ?

If iron atom is available in the form of , say three isotopes ""_(25)^(54)"Fe", ""_(26)^(56)Fe and " "_(26)^(57)Fe and their proportion is 5% , 90% and 5% respectively. Calculate the average mass of iron atom.

If I_(1) is the first ionisation potiential I_(2) is the second ionsation potential I_(3) is the thirs ionsiation potentialand I_(4) is the fourth ionisation potential of anelement then which of the following has the laest value?

If Dobereiner is related with 'law of triads', then Newlands is related with

If dispersing medium is liquid and dispersed phase is gas, then what is this type of colloid called ?

If cold water is poured on flask containing very hot distilled water and water vapour, thewater inside the flask started to boil below 100^(@)C. The principle involved is __________.

If canal ray experiments are conducted with different isotopes of hydrogen gas, do the canal rays produced show that same deflection under the external eletric field? Give reasons to support your answer.

If Bromine atom is available in the form of say, two isotopes ._(35)^(79)Br(49.7%) and ._(35)^(81)Br(50.3%) Calculate the average atomic mass of Bromine atom.

If bromine atom is available in the form of, say two isotopes""_(35)^(79)Br (49.7%) and ""_(35)^(85)Br (50.3%). Calculate the average atomicmass of bromine atom.

If an atom contains one electron and one proton, will it carry any charge or not ?

If A = 23 and Z = 11 for Na atom, how many protons, electrons and neutrons are present in Na atom ?

If 6 g of a metal gets deposited by passing 2 amp of current for 2 h 30 min, calculate the equivalent weight of the metal.

If ""^12C is used as standard , the relative mass of an atom of sodium is 23 and the relative mass of an atom of phosphorus is 31 . Find the relative masses of a samples of sodium and phosphorus with respect to each other when each contains 3.0 xx 10^(25) atoms .

If 12 g is carbon is burnt in the presence of 32g of oxygen, how much CO_(2) will be formed.

Identity the relation and fill up the blank. Law of electrolysis : _______

Identity the relation and fill up the blank. Law of conservation of mass : ________

Identity the correct sequence of fraction obtained when petroleum is subjectd to fractional distillation . lubricaing oil petrol petroleum ether diesel oil

Identify whether the given substance is mixture or compound and justify your answer.

Identify the solutions among the following mixtures : (a) Soil, (b) Sea water, ( c) Air, (d) Coal and (e) Soda water.

Identify the solutionsamong the Followingmixtures. (a)Soil (b) Sea water (c ) Air (d) Coal ( e) Soda water?

Identify the oxide which forms the strongest base:

Identify the mixture which can be separated by magnetic separated bymagnetic separation method.

Identify the methods by which the individual components of mixture containing water, potassium nitrate, sodium chloride, alcohol and carbon tetrahedron can be separated.

Identify the following reactions as oxidation or reduction (a). Na to Na^(+)+ e^(-) (b) Fe^(3+)+ 2e^(-) to Fe^(+)

Identify the compounds as Ionic Covalent/Coordinate based on thegiven characteristics.

Identify the colloids from the following : Soda water, milk, sponge, clouds, mixture of alcohol and water, jelly.

Identify colloids from the following :Copper sulphate solution, milk, smoke, muddy water, butter, sugar solution, face cream, lemonade.

Ice , water and vapour are ................ the same .

Ice floats on the surface of water because

Ice floats on water because thedensity of ice is……..than that of water.

(i) Pressure cooker reduces the cooking time. Explain the priciple involved. (ii) Fish and meat can be preserved for a longer time in ice if common salt is added to it. Give reason. (iii) When a glass of ise and cold water is kept open at room temperature, what observation is found ? Give reason.

(a) What is fractional distillation ? What is the use of fractionating column in fractional distillation? (b) Draw a labelled diagram of the fractional distillation apparatus distillation apparatus used for separating a mixture of alcohol and water

(i) Diamond is a better conductor of heat than copper and silver. Give appropritate reasons. (ii) Graphite is a good conductor of electricity . Justify the statement.

(i) Calculate the weight of aluminium deposited during the electrolysis of molten aluminium chloride by passing 193 amp of current for 500 min.

(i) Calculate molar mass of Al(OH)_(3). (Al = 27 u, O = 16 u, H = 14) (ii) Write chemical formulae of ammonium carbonate and magnesium chloride. (iii) Write the difference between atom and molecule.

(i) Account for the changes observed in the surroundings when carbon dioxide gas comes out of a fire extinguisher. (ii) Althoguh CO_2 is generally used a material in fire extinguisher it cannot be used toput out fires casued by metals like Na. Mg and K.

Hydrogen sulphide on reacting with aqueous solution of metal salts converts them to ___________________.

Hydrogen has...... Isotopes. Two, three, four)

Hydrogen gas kept in a vessel spreads throughout the spaceof the vessel .

Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?