8881 + Interview Questions in Chemistry in Class 10 Page 13 InterviewSolution

601.	Which of the following is a good conductor of electricity ?
Answer» CHARCOAL coke graphite diamond SOLUTION :Graphite is a good conductor of ELECTRICITY due to the presence of free ELECTRONS.

Discussion

602.	To isolate active metals, water solution of the metal salt cannot be used for electrolysis. Give reason.
Answer» Solution :Because active metals react with water. Moreover, the hydrogen ION of water gets reduced to hydrogen gas before the cations of active metals can be reduced by passing electric CURRENT.

Discussion

603.	The volume of CO_(2) liberated at STP is_________ , on thermaldecomposition of 84 g of sodium bicarbonate.
Answer» ANSWER :`11.2` L

Discussion

604.	What are strong and weak acids ? In the following list of acids, separate strong acids from weak acids : Hydrochloric acid, citric acid, acetic acid, nitric acid,formic acid , sulphuric acid.
Answer» SOLUTION :In AQUEOUS solutions ,strong acids ionise completely and PROVIDE hydronium ions . On the other hand , WEAK acids are partially ionised and an aqueous solution of same molar concentration provides a much SMALLER concentration of `H_(3)O^(+)` ions. Strong acids - Hydrochloric acid, sulphuric acid , nitric acid. Weak acids - Citric acid , acetic acid, formic acid.

Discussion

605.	Translate the following statements into chemical equations and balance them: (i) Lead nitrate reacts with sulphuric acid to form a precipitate of lead sulphate and nitric acid. (ii) Magnesium burns in the presence of nitrogen to form magnesium nitride. (iii) Aluminium metal strip is added in hydrochloric acid to produce aluminium chloride and hydrogen gas.
Answer» SOLUTION :(i) `PB(NO_(3))_(2)(aq)+H_(2)SO_(4)(aq)rarrPbSO_(4)(s)+2HNO_(3)(aq)` (ii) `3Mg(s)+N_(2)(g)overset(Delta)rarrMg_(3)N_(2)(s)` (iii) `2Al(s)+6HCl(aq)rarr2AlCl_(3)(aq)+3H_(2)(g)`

Discussion

606.	Which of the following reaction will not take place?
Answer» `ZN + FeSO_(4) to ZnSO_(4) + H_(2) O` `2K1 + C1_(2) to 2KC1 + I_(2)` `Zn + MgSO_(4) to ZnSO_(4) + MG` `Mg + CuSO_(4) to MgSO_(4) + Cu` Solution :`Zn + MgSO_(4) to ZnSO_(4) + Mg` does not take PLACE because Zn is LESS reactive than Mg and count displace Mg from `MgSO_(4)` solution

Discussion

607.	You have three solutions whose pH values are 2, 7 and 11 respectively. Out of the above solutions, which solution is neutral ?
Answer» SOLUTION :Solution B.

Discussion

608.	What is the oxidation number of S in S_(8).
Answer» ANSWER :ZERO

Discussion

609.	There are 115 elements known till today. Some of them are metals and some are non-metals. Metals are usually hard, malleable and ductile and have metallic lustre. Non-metals are usually soft, do not posses lustre and are not malleable and ductile. But iodine is a non-metal which has metallic lustre. Iodine is also important for us. Non-metals are bad conductors of heat and electricity. (i) Why iodine is important for us ? (ii) Name a non-metal which is good conductor of heat and electricity. (iii) As a student, what initiative you will take to comment on the statement that "Iodised salt is good for health". Give any two suggestions.
Answer» Solution :(i) Deficiency of iodine leads to goitre. It ALSO leads to hypothyroidism, a most COMMON disease among ladies above 40 years of AGE. (ii) Graphite is a non-metal which is a good conductor of heat and electricity. (iii) Suggestions : a) To start an awareness campaign in localities, HOMES and SCHOOLS. (b) To make understand the importance of iodine to people.

Discussion

610.	Which one of the following has maximum number of atoms?
Answer» `"18 g of "H_(2)O` `"18G of "O_(2)` `"18 g of "CO_(2)` `"18 g of "CH_(4)` Solution :Hint : `"Number of atoms"=("Mass of substance")/("Molar mass")xxN_(A)xx"Number of atoms in the MOLECULE"` `"18 g of "H_(2)O=(18)/(18)xxN_(A)xx3=3N_(A)` where `N_(A)=6.023xx10^(23)` (b) `"18 g of "O_(2)=(18)/(32)xxN_(A)xx2=1.12N_(A)` (C ) `"18 g of "CO_(2)=(18)/(44)xxN_(A)xx3=1.23N_(A)` (d) `"18 g of "CH_(4)=(18)/(16)xxN_(A)xx6=5.60N_(A)` `therefore` (d) is the correct answer.

Discussion

611.	The rectified spirit contains……………….
Answer» 100% ETHANOL 50% ethanol +50% water 95.5% ethanol and 4.5% water Ethanol + Pyridine Answer :C

Discussion

612.	The sulphide ore among the following is
Answer» Haematite Bauxite Argentite ZINE blende Answer :D

Discussion

613.	Zinc and hydrochloric acid react according to the reaction: Zn_((s))+2HCl_((aq.))rarr ZnCl_(2(aq.))+H_(2(g)) If 0.30 mole of Zn are added to hydrochloric acid containing 0.52 mole HCl, how many moles of H_(2) are produced?
Answer» ANSWER : HCl is limiting REAGENT; `H_(2)`formed `=` 0.36 MOL

Discussion

614.	Which of the following are environment friendly practies ?
Answer» Carrying cloth - bags to PUT PURCHASES while shopping. Switching of UNNECESSARY light & fans Walking to SCHOOL instead of getting your mother to drop you on her scooter All the above Answer :D

Discussion

615.	Write the reaction between chloroethane and an aqueous solution of potassium hydroxide
Answer» SOLUTION :`C_2H_5Cl + KOH(AQ) to C_2H_5OH + KCL`

Discussion

616.	Write the SI unit of entropy.
Answer» SOLUTION :`JK^(-1) MOL^(-1)`

Discussion

617.	Which of the following statements are correct for the given hydrocarbon compounds ? (1) H-underset(H)underset(\|)overset(H)overset(\|)C-underset(H)underset(\|)overset(H)overset(\|)C-underset(H)underset(\|)overset(H)overset(\|)C-underset(H)underset(\|)overset(H)overset(\|)C-underset(H)underset(\|)overset(H)overset(\|)C-H
Answer» Three hydrocarbon compounds can be represented by a general FORMULA. Three hydrocarbon compounds are ISOMERS of each other. Three hydrocarbon compounds are unsaturated hydrocarbons. Chemical reactions of three hydrocarbon compounds are SIMILAR. Answer :A::B::D

Discussion

618.	What will happen if a solution of sodium hydrogencarbonate is heated ? Give the equation of reaction involved
Answer» Solution :Sodium hydrogencarbonate solution on heating GIVES sodium carbonate, carbon dioxide and water as per the following equation : `2NaHCO_(3) OVERSET("Heat") rarr Na_(2)CO_(3)(aq) + H_(2)O(l)+(CO_2)(g)`

Discussion

619.	Write the names and formulae of mono-, di- and triprotic acids.
Answer» Solution :(i) HCl (ii) `H_(2)SO_(4)` (iii) `H_(3)PO_(4)`

Discussion

620.	Which element is iso-electronic with Na^+? [Given a atomic number of Sodium (Na) : 11]
Answer» ANSWER :NE

Discussion

621.	Write the balnced equation for the following chemical reactions : to Sodium hydroxide + Hydrogen.
Answer» SOLUTION :Balaced EQUATIONS In the SYMBOLIC from are GIVEN as under : `2Na+2H_(2)Oto2NaOH+H_(2)`

Discussion

622.	Whatis electroplating ?
Answer» SOLUTION :Electroplatingis a methodof coatingone metaloveranothermetal by passingelectric CURRENT .

Discussion

623.	Why a brown coating is formed on the rod when iron rod is kept dipped in copper sulphate solution for sometime > What change will be observed in the colour of the solution ?
Answer» SOLUTION :Iron being more REACTIVE than copper, displaces copper from copper sulphate by the following reaction : `Fe+underset("Blue")(CuSO_(4))tounderset("green")underset("Light")(FeSO_(4))+underset("colour")underset(Brown")(Cu)` Brown coating of copper is deposited on the iron rod. Colour of the solution becomes green due to the formation of FERROUS sullphate.

Discussion

624.	What is the sign of Delta H " for " H_(2) (g) rarr 2H (g) ?
Answer» SOLUTION :`DELTA H = -ve

Discussion

625.	What is meant by substitution reaction ? Explain.
Answer» Solution :Reaction in which substitution of an atom or a group of atoms in an organic compound takes place by ANOTHER atom or group of atoms is called substitution reaction. Saturated hydrocarbons are fairly unreactive and are inert in the presence of most of the reagents. Chlorination of hydrocarbon COMPOUNDS takes place in the presence of sunlight. Chlorine can replace the hydrogen atoms one by one. This type of reaction is called substitution reaction. `underset("Methane")(CH_(4))+Cl_(2)OVERSET("Sunlight")to underset("Chloromethane")(CH_(3)Cl)+HCl` A number of products in this reaction are formed with the higher homologous of alkanes.

Discussion

626.	What acid is produced in fatigued muscles after doing a vigorous exercise ?
Answer» SOLUTION :LACTIC ACID

Discussion

627.	Which of the following chemical species is most stable?
Answer» `O_(2)` `O_(2)^(+)` `O_(2)^(-)` `O_(2)^(2-)` ANSWER :B

Discussion

628.	Why are metals malleable and ductile?
Answer» Solution :When a large amount of shearing FORCE is APPLIED to a metal, the metal kernels of one layer slide over the other. After getting displaced, the metal kernels again get stabilised there due to the uniform distribution of free electrons THROUGHOUT the metal. Hence metals can be permanently deformed with-out breaking and EXHIBIT malleability and ductility.

Discussion

629.	The valency of the carbonate radical is
Answer» 1 2 3 4 Solution :2

Discussion

630.	Which type of compounds can be formed by carbon ?
Answer» SOLUTION :COVALENT COMPOUNDS.

Discussion

631.	Which of the following is the correct formulae of molarity
Answer» `(% "by weight" XX 10 xxd) / (Gram MOLECULAR MASS)` `(% "by weight" xx 10 ) / (Gram Molecular mass xx d)` `(% "by weight" xx 10 xxd^2) / (Gram Molecular mass)` None of the above Answer :A

Discussion

632.	What is the mass percent of carbon in carbon dioxide?
Answer» `0.034%` `27.27%` `3.4%` `28.7%` SOLUTION :Molecular mass of `CO_(2)=12+2xx16=44` Mass of C in `CO_(2)=12g` `:.%C=12/44xx100=27.27%`

Discussion

633.	Which one of the following acts as a reducing agent ?
Answer» oxygen CARBON calcium potassium ANSWER :B

Discussion

634.	Which of the following are the characteristics of isotopes of an element ? (i) Isotopes of an element have same atomic masses. (ii) Isotopes of an element have same atomic number. (iii) Isotopes of an element show same physical properties. (iv) Isotopes of an element show same chemical properties.
Answer» (i), (II) and (iv) (ii), (iii) and (iv) (ii) and (iii) (ii) and (iv) Solution :Isotopes of an element have the same ATOMIC number and they show same CHEMICAL PROPERTIES.

Discussion

635.	The value of planck's constant is "____________"
Answer» ANSWER :`6.627 xx 10 ^(-27) ERGS or 6.627 xx 10 ^(-34)` J

Discussion

636.	Write the formulae and names of the first three carboxylic acids.
Answer» SOLUTION : (a) HCOOH= Methanoic acid, (B) `CH_3COOH` = Ethanoic acid, (C) `CH_3CH_2COOH` = PROPANOIC acid

Discussion

637.	What are the vertical columns and the horizontal rows called in Mendeleev's periodic table ?
Answer» SOLUTION :GROUPS and PERIODS

Discussion

638.	You have three solutions A, B and C whose pH values are 4, 7 and 10 respectively. Out of the above solutions, which solution is acidic ?
Answer» SOLUTION :Solution A.

Discussion

639.	What are ionic compounds ? List two properties of these compounds.
Answer» Solution :The COMPOUNDS which have bonds formed by loss and GAIN of electrons are called ionic compounds or electrovalent compounds. Two properties of Ionic compounds i) Ionic compounds are HARD and brittle. ii) TONIC compounds have high melting and BOILING points.

Discussion

640.	What are meant by periodic properties? Give examples.
Answer» Solution :Those PROPERTIES which are determined by the electronic configuration of elements or which depend on electronic configuration of elements are KNOWN as periodic properties. OR The properties which SHOW a recurring gradation within the same group or along a PERIOD are known as periodic properties. For example, valency, atomic radii (atomic SIZE), metallic property, electronegativity, etc.

Discussion

641.	Which of the following is the outermost shell for elements of period 2 ?
Answer» K shell L shell M shell N shell Solution :For the SECOND period elements, L-shell is the OUTERMOST shell.

Discussion

642.	Which of the following it most suitable for the core of electionmagnetics
Answer» AIR SOFT iron steel None of these Answer :B

Discussion

643.	Which of the following weighs the most?
Answer» `10^23` molecules of `H_2` 1 MOLE of `H_2O` 1 mole of `N_2` `10^22` atoms of oxygen Solution :(i) `10^23` molecules of `H_2` `= (10^23)/(6.02 XX 10^23) = 0.167` moles of `H_2` ` = 0.167 xx 2= 0.234g H_2` (II) 1mole of `H_2O = 1 xx 2 + 16 = 18g H_2O` (iii) 1 mole of `N_2 = 2 xx 14 = 28 g N_2` (iv) `10^22` atoms of O ` = (10^22)/(6.02 xx 10^23) = 0.0167` moles of O ` = 0.0167 xx 16 = 0.2672 g O`

Discussion

644.	What is the action of heat on copper ?
Answer» Solution : On heating at different temperature in the presence of oxygen , COPPER forms two types of oxide `CuO,Cu_(2)O` `2Cu+O_(2)UNDERSET(DELTA)OVERSET("below"1370K)to 2CuO` Copper (II) ixde - black `4Cu+O_(2)underset(Delta)overset("above"1370K)to2Cu_(2)O` Copper (I) Oxide -red

Discussion

645.	The role of manganese dioxide in the decomposition of potassium chlorate is …………..
Answer» ACT as a reactant Act as a catalyst Act as a regent Act as a REATION medium Answer :A::C

Discussion

646.	Urea was first organic compound to be synthesised by
Answer» LAMINAR Wohlar Beryine Haber SOLUTION :Wohlar

Discussion

647.	What do you mean by : (a) Displacement reaction ? (b) Reduction reaction ? Combination reaction ? Write balanced chemical equations.
Answer» Solution :(a) Displacement reaction : A reaction in which a more reactive metal displaces a LESS reactive metal from its salt solution in called displacement reaction. For example, `Zn(s)+CuSO_(4)(aq)toZnSO_(4)(aq)+Cu(s)darr` (B) Reduction reaction : A reaction in which hydrogen is ADDED or oxygen is removed is called reduction reaction. For example, `ZnO+C to Zn+Co` In this reaction reduction of ZnO to Zn has taken place. (c) Combination reaction : A reaction in which two or more reactants combine to GIVE a single product is called combination reaction. For example, `CaO(s)+H_(2)O(l)tounderset("(Slaked lime)")(Ca(OH)_(2)(aq))`

Discussion

648.	Write the chemical equation to represent the action of atmospheric CO_2 gas on bleaching powder when exposed in open.
Answer» Solution :BLEACHING POWDER has a tendency to decompose on exposure to atmospheric `CO_(2)` `CaOCl_(2) rarr CaO_(3) + Cl_(2)` It release CHLORINE gas and loses its ACTIVITY as a bleaching AGENT

Discussion

649.	The traditional method of sustainable natural resource management is
Answer» FOLLOWING WATER HARVESTING method Minimising the establishment of factories Using fossil fuels abundantly Preventing OVERGRAZING of cattle in forest areas Solution :Following water harvesting method

Discussion

650.	What is galvanization ?
Answer» SOLUTION :The PROCESS of covering IRON with is CALLED galvanization.

Discussion

Explore topic-wise InterviewSolutions in .

Which of the following is a good conductor of electricity ?

To isolate active metals, water solution of the metal salt cannot be used for electrolysis. Give reason.

The volume of CO_(2) liberated at STP is_________ , on thermaldecomposition of 84 g of sodium bicarbonate.

What are strong and weak acids ? In the following list of acids, separate strong acids from weak acids : Hydrochloric acid, citric acid, acetic acid, nitric acid,formic acid , sulphuric acid.

Which of the following reaction will not take place?

You have three solutions whose pH values are 2, 7 and 11 respectively. Out of the above solutions, which solution is neutral ?

What is the oxidation number of S in S_(8).

Which one of the following has maximum number of atoms?

The rectified spirit contains……………….

The sulphide ore among the following is

Zinc and hydrochloric acid react according to the reaction: Zn_((s))+2HCl_((aq.))rarr ZnCl_(2(aq.))+H_(2(g)) If 0.30 mole of Zn are added to hydrochloric acid containing 0.52 mole HCl, how many moles of H_(2) are produced?

Which of the following are environment friendly practies ?

Write the reaction between chloroethane and an aqueous solution of potassium hydroxide

Write the SI unit of entropy.

What will happen if a solution of sodium hydrogencarbonate is heated ? Give the equation of reaction involved

Write the names and formulae of mono-, di- and triprotic acids.

Which element is iso-electronic with Na^+? [Given a atomic number of Sodium (Na) : 11]

Write the balnced equation for the following chemical reactions : to Sodium hydroxide + Hydrogen.

Whatis electroplating ?

Why a brown coating is formed on the rod when iron rod is kept dipped in copper sulphate solution for sometime > What change will be observed in the colour of the solution ?

What is the sign of Delta H " for " H_(2) (g) rarr 2H (g) ?

What is meant by substitution reaction ? Explain.

What acid is produced in fatigued muscles after doing a vigorous exercise ?

Which of the following chemical species is most stable?

Why are metals malleable and ductile?

The valency of the carbonate radical is

Which type of compounds can be formed by carbon ?

Which of the following is the correct formulae of molarity

What is the mass percent of carbon in carbon dioxide?

Which one of the following acts as a reducing agent ?

Which of the following are the characteristics of isotopes of an element ? (i) Isotopes of an element have same atomic masses. (ii) Isotopes of an element have same atomic number. (iii) Isotopes of an element show same physical properties. (iv) Isotopes of an element show same chemical properties.

The value of planck's constant is "____________"

Write the formulae and names of the first three carboxylic acids.

What are the vertical columns and the horizontal rows called in Mendeleev's periodic table ?

You have three solutions A, B and C whose pH values are 4, 7 and 10 respectively. Out of the above solutions, which solution is acidic ?

What are ionic compounds ? List two properties of these compounds.

What are meant by periodic properties? Give examples.

Which of the following is the outermost shell for elements of period 2 ?

Which of the following it most suitable for the core of electionmagnetics

Which of the following weighs the most?

What is the action of heat on copper ?

The role of manganese dioxide in the decomposition of potassium chlorate is …………..

Urea was first organic compound to be synthesised by

What do you mean by : (a) Displacement reaction ? (b) Reduction reaction ? Combination reaction ? Write balanced chemical equations.

Write the chemical equation to represent the action of atmospheric CO_2 gas on bleaching powder when exposed in open.

The traditional method of sustainable natural resource management is

What is galvanization ?