8881 + Interview Questions in Chemistry in Class 10 Page 94 InterviewSolution

4651.	Is common salt a major chemical present in seawater ?
Answer» ANSWER :YES

Discussion

4652.	Is CH_(3)-CH_(2) -underset(CH_(3))underset(\|)(CH_(2)) a brached -chain hydrocarbon ?
Answer» ANSWER :No

Discussion

4653.	Is burning of a candle wax a physical change or a chemical change ?
Answer» SOLUTION :It is a CHEMICAL CHANGE.

Discussion

4654.	Is an alkyl group represented by the general formulaC_(n)H_(2n+1) ?
Answer» ANSWER :YES

Discussion

4655.	Is a true solution homogeneous or heterogeneous ?
Answer» SOLUTION :HOMOGENEOUS

Discussion

4656.	………..is a substance which furnishes H^(+) ions when dissolved in water and a ……………… is a substance which furnishes OH^(-) ions in water.
Answer» SOLUTION :AID,BASE

Discussion

4657.	_______isa reactionis whichtwolikemoleculesreactto giveions.
Answer» SOLUTION :SELF - IONISATION

Discussion

4658.	________isa stateof a physicalchangeat whichthe volumeof allphasesremainunchanged .
Answer» SOLUTION :physicalequilibrium

Discussion

4659.	Is a mixture of caustic soda and quicklime called sodalime ?
Answer» ANSWER :YES

Discussion

4660.	Is a mixture of ethonal and water called antifreeeze ?
Answer» ANSWER :YES

Discussion

4661.	Is a mixture containing 95.6% ethanol and 4.4 % water called rectified spirit ?
Answer» ANSWER :YES

Discussion

4662.	……………is a double salt.
Answer» SODIUM chloride Washing soda Potash alum Bleaching powder Answer :A

Discussion

4663.	Is a combustible substance necessary for combustion to take place ?
Answer» ANSWER :YES

Discussion

4664.	Irreversible reaction is relatively slow.
Answer» Solution :FALSE Correct STATEMENT:IRREVERSIBLE REACTION is FAST

Discussion

4665.	Iron when dipped in conc. HNO_3 becomeschemically inert . Give reason .
Answer» Solution :When IRON is dipped in conc. `HNO_3` , it BECOMES chemically passive or inet due to the formationof a layer of iron OXIDE `(Fe_2O_3)`on its surface .

Discussion

4666.	Iron will displace which one from its compound?
Answer» Zn Al CU Mg Solution :Cu

Discussion

4667.	Iron reacts with dilute HCl to form
Answer» `FeCl_(2)` `FeCl_(3)` both (a) and (b) `FeCl_(3)+H_(2)` ANSWER :A

Discussion

4668.	Iron reacts with Chlorine to form …………….
Answer» SOLUTION : FERRIC CHLORIDE

Discussion

4669.	Iron pyrites are converted to iron oxide by the process of ______.
Answer» ANSWER :ROASTING

Discussion

4670.	"Iron nails rust in test tube A, but, iron nails do not rust in test tubes B and C." Explain it
Answer» Solution : It is observed in activitythat IRON nails kept in TEST tube A are EXPOSED to both air and water. Hence, iron nails rust in test tube A. In the test tube B, the iron nails are exposed to water only but not to air. Iron nails in test tube C are exposed to dry air only and not to water. Hence, iron nails do not rust in test tubes B and C. Remember: For rusting, metal must be exposed to both air and water (MOISTURE).

Discussion

4671.	Iron nails were added to ferrous sulphate solution in a test tube and kept for some time. The colour of iron nails became brownish. The reaction that takes place in categorised as
Answer» Decomposition REACTION. Combination reaction Double decomposition reaction. Displacement reaction. Solution :Iron DISPLACES COPPER from copper sulphute which deposits on iron NAILS.

Discussion

4672.	Iron is galvanized by coating it with :
Answer» Nickel Copper Chromium Zinc Answer :D

Discussion

4673.	Iron is coated with two metals A and B separately. When the coating is partially worn away, it is still proctected when coated with A and not by B. Explain with reference to electrochemical series.
Answer» SOLUTION :(i) Comparison of electropositivity of A, B and Fe. (ii) Comparison of standard reduction potential of A, B and iron. (iii) Relation between standard reduction potential of an ELEMENT and the tendency of GETTING oxidised. (iv) Relation between the tendency of a metal to get oxidised and its ABILITY to protect iron from corrosion

Discussion

4674.	Iron is a lustrous greyish white metal and can be magnetised.
Answer» SOLUTION :N/A

Discussion

4675.	Iron (III) oxide is heated with aluminium powder forms iron in the molten state. This process is known as........
Answer» SOLUTION : THERMIT PROCESS

Discussion

4676.	Iron displaces copper from copper sulphate solution because
Answer» COPPER is more reactive than iron copper and iron EQUALLY reactive iron is more reactive than copper none of the above is true Answer :C

Discussion

4677.	Iron containing 2-4.5% of carbon is called ____________
Answer» SOLUTION :PIG IRON

Discussion

4678.	Iron can form two types of inos. Compare the ionic sizes of the respective ions.
Answer» Solution :Both `FE^(2+) and Fe^(3+) have the same nume of protons but the NUMBER of electron in `Fe^(3+)` is less than ltBrgt that of `Fe^(2+)` . HENCE the effective nuclear CHARGE is more in the case of `Fe^(3+)` and thereby the ionic SIZE of `Fe^(3+) ` is less than that of `Fe^(2+)` .

Discussion

4679.	Iron burns in air to from
Answer» `FEO` `Fe_(2)O_(3)` `Fe_(3)O_(4)` `FeO_(2)` ANSWER :B

Discussion

4680.	Iqbal treated a lustrous, divalent element M with sodium hydroxide, He observed the formation of bubbles in reaction mixture. He made the same observations when this element was treated with hydrochloric acid, Suggest how can he identify the produced gas. Write chemical equations for both the reactions.
Answer» Solution :The ELEMENT is a METAL `M+2NaOH to Na_2MO_2+H_2` `M+2HCl to MCl_2+H_2` The produced gas can be identified by BRINGING a burning matchstick near the reaction vessel . The gas burns with a pop SOUND The confirms that the gas is `H_2`.

Discussion

4681.	Ions are formedwhen an atom ___________ electrons.
Answer» SOLUTION :LOSE or GAIN

Discussion

4682.	Ionisation potential increases in a period from left to right because
Answer» ATOMIC RADIUS increases and nuclear CHARGE increases. atomic radius decreases and nuclear charge decreases. atomic radius increases and nuclear charge decreases. atomic radius decreases and nuclear charge increases. Solution :atomic radius decreases and nuclear charge increases.

Discussion

4683.	ionisation potential decreases down the group in representative elements while transition elements of the 6th period have greater ionisation potential values compared to the elements of the 5th period. Justify.
Answer» SOLUTION :(i) factors EFFECTING ionisation potential (II) comparison of the screening effects of s, p, d and F ELECTRONS

Discussion

4684.	Ionisation energy decreasesdown the group in periodic table. Give reason .
Answer» Solution :Downthe group, atomic size increases and hencethe VALENCE ELECTRONS are loosely BOUND. They require relatively less ENERGY for the removal . Thus IONISATION energy decreasesdown the group in periodictable.

Discussion

4685.	Ionic radius increases across the period from left to right.
Answer» Solution :IONIC radius decreases ACROSS the PERIOD from left to RIGHT.

Discussion

4686.	Ionic radii decreases along the ___________.
Answer» SOLUTION :PERIOD

Discussion

4687.	Ionic compounds conduct electricity only in solution.
Answer» Solution :False – IONIC COMPOUNDS can CONDUCT electricity in molten state ALSO

Discussion

4688.	Ionic bond formation takes place between sodium and chlorine. But between hydrogen and chlorine, covalent bond formation takes place. Give reason.
Answer» Solution :Sodium belongs to IA group and is highly ELECTROPOSITIVE. Chlorine belongs to VII A group and is highly electronegative. Sodium has very low IP value and can form `Na^(+)` ion easily. CHLROINE has very high IP value and high EA value and can form `Cl^(-)` ion easily. Thus, ionic bond results between sodium and chlorine. IP value of hydrogen is not as low as alkali metals, that is, Na. Hence, its tendency to form `H^(+)` ion is very less. Sharing of electrons takes place between hydrogen and chlorine RESULTING in the formation of polar covalent bond.

Discussion

4689.	Iodine is a ........., but it possesses ..........
Answer» SOLUTION : non-metal, LUSTRE

Discussion

4690.	Intermolecular space is the least in
Answer» water steam ICE all of them SOLUTION :ice

Discussion

4691.	Intake of small quantity of methanol can be lethal. Comment.
Answer» SOLUTION :METHANOL is oxidised to methanal in the liver. Methanal REACTS rapidly with the components of cells. It causes the protoplasm to coagulate. It also AFFECTS the optic nerve, causes blindness.

Discussion

4692.	Intake of small amount of methanol can be fatal. Comment .
Answer» Solution :Methano, when INGESTED, can AFFECT the CENTRAL NERVOUS system and MAY lead to death.

Discussion

4693.	Insulation of electric wire is done by
Answer» POLY ISOPRENE neoprene poly vinyl Chloride poly Buta - 1, 3 diene Answer :C

Discussion

4694.	Inner Transition elements
Answer» Solution :The f-block elements are PLACED at the BOTTOM of the periodic table and they have last three shells INCOMPLETELY filled . These elements are called Inner Transition Elements.

Discussion

4695.	Inner-Transition Elements.
Answer» SOLUTION :(i) Elements PLACED in two separate rows at thebottom of the periodic table are called innertransition elements. (ii) They include two series of elements: Lanthanideseries and Actinide series. They belong to f-blockelements of Modem Periodic table. (iii) 14 elements with atomic number 58 to 71(CERIUM to Lutetium) are called lanthanides.These elements are placed ALONG with lanthanum(La= 57) in group 3 and period 6 because of veryclose resemblance in properties between them. (iv) 14 elements with atomic number 90 to 103(THORIUM to Lawrencium) are called actinides.These elements are placed along with actinium(Ac= 89) in group 3 and period7 because of veryclose resemblance in their properties. (v)They have last three shells incompletely filled. (vi) All these elements are metals.

Discussion

4696.	Initial number of moles of reactants taken in a closed reaction vessel is given. Percentage degree of dissociation is also given . Identify the correct sequence of steps to calculate k_(c)value. (1) calculation of equilibriumconcentrations of reactants and products (2) calculation of equilibrim concentration number of moles (3) writing equilibrium constant expression for the reaction (4) calculation of k_(c) value by using the equilibrium concentration
Answer» 4,2,3,1 2,1,3,4 3,2,1,4 2,1,4,3 Solution :(i) calculate of equilibrium number of moles (ii) calculation of equilibrium concentrations of reactants and products (iii) writing equilibrium expression for the reaction (iv) calculate of `k_(C)` value by USING the equilibrium CONCENTRATION

Discussion

4697.	Inert gases exist in the form of free atoms.
Answer» Solution :(i) For m ation of molecules is based on the electronicconfiguration of the combining elements. (ii) In the case of inert gases, all the shells, INCLUDING the outermost shell are completely filled. (iii) They have electronic configuration with complete duplet or complete octet. (iv) Due to their stable electronic configuration, ATOMS of these elements do not lose, gain or share electrons with other atoms. Hence, inert gases EXIST in the FORMS of free atoms.

Discussion

4698.	Inert gases are placed in a separate group in the Modem Periodic Table. (a) State the group number. (b) How many valence electrons do most of these gases have? (c) Why are they unreactive? (d) Name any two inert gases.
Answer» Solution :(a) Group number for inert GASES in the PERIODIC Table is 18. (b) Except helium, these gases have 8 valence electrons. (c) Their octet is already complete. Therefore they have no tendency to react. (d) (i) NEON. (II) Argon.

Discussion

4699.	Inert gases are placed in a separate group in the Modern Periodic Table a) State the group number. b) How many valence electrons do most of them have? c) Why are they unreactive? d) Name any two inert gases.
Answer» Solution :(a) GROUP number of INERT gases is 18. (B) 8. (c) They are unreactive since their valence shell is completely filled. Hence they have no tendency to lose or gain ELECTRONS by participating in a chemical reaction. (d) HELIUM and Neon (or any other group 18 elements).

Discussion

4700.	Inert gases and Normal Elements
Answer» SOLUTION :

Discussion

Explore topic-wise InterviewSolutions in .

Is common salt a major chemical present in seawater ?

Is CH_(3)-CH_(2) -underset(CH_(3))underset(|)(CH_(2)) a brached -chain hydrocarbon ?

Is burning of a candle wax a physical change or a chemical change ?

Is an alkyl group represented by the general formulaC_(n)H_(2n+1) ?

Is a true solution homogeneous or heterogeneous ?

………..is a substance which furnishes H^(+) ions when dissolved in water and a ……………… is a substance which furnishes OH^(-) ions in water.

_______isa reactionis whichtwolikemoleculesreactto giveions.

________isa stateof a physicalchangeat whichthe volumeof allphasesremainunchanged .

Is a mixture of caustic soda and quicklime called sodalime ?

Is a mixture of ethonal and water called antifreeeze ?

Is a mixture containing 95.6% ethanol and 4.4 % water called rectified spirit ?

……………is a double salt.

Is a combustible substance necessary for combustion to take place ?

Irreversible reaction is relatively slow.

Iron when dipped in conc. HNO_3 becomeschemically inert . Give reason .

Iron will displace which one from its compound?

Iron reacts with dilute HCl to form

Iron reacts with Chlorine to form …………….

Iron pyrites are converted to iron oxide by the process of ______.

"Iron nails rust in test tube A, but, iron nails do not rust in test tubes B and C." Explain it

Iron nails were added to ferrous sulphate solution in a test tube and kept for some time. The colour of iron nails became brownish. The reaction that takes place in categorised as

Iron is galvanized by coating it with :

Iron is coated with two metals A and B separately. When the coating is partially worn away, it is still proctected when coated with A and not by B. Explain with reference to electrochemical series.

Iron is a lustrous greyish white metal and can be magnetised.

Iron (III) oxide is heated with aluminium powder forms iron in the molten state. This process is known as........

Iron displaces copper from copper sulphate solution because

Iron containing 2-4.5% of carbon is called ____________

Iron can form two types of inos. Compare the ionic sizes of the respective ions.

Iron burns in air to from

Ions are formedwhen an atom ___________ electrons.

Ionisation potential increases in a period from left to right because

ionisation potential decreases down the group in representative elements while transition elements of the 6th period have greater ionisation potential values compared to the elements of the 5th period. Justify.

Ionisation energy decreasesdown the group in periodic table. Give reason .

Ionic radius increases across the period from left to right.

Ionic radii decreases along the ___________.

Ionic compounds conduct electricity only in solution.

Ionic bond formation takes place between sodium and chlorine. But between hydrogen and chlorine, covalent bond formation takes place. Give reason.

Iodine is a ........., but it possesses ..........

Intermolecular space is the least in

Intake of small quantity of methanol can be lethal. Comment.

Intake of small amount of methanol can be fatal. Comment .

Insulation of electric wire is done by

Inner Transition elements

Inner-Transition Elements.

Inert gases exist in the form of free atoms.

Inert gases are placed in a separate group in the Modem Periodic Table. (a) State the group number. (b) How many valence electrons do most of these gases have? (c) Why are they unreactive? (d) Name any two inert gases.

Inert gases are placed in a separate group in the Modern Periodic Table a) State the group number. b) How many valence electrons do most of them have? c) Why are they unreactive? d) Name any two inert gases.

Inert gases and Normal Elements