8881 + Interview Questions in Chemistry in Class 10 Page 32 InterviewSolution

1551.	What is a homologous series? Explain with an example .
Answer» Solution :Homologous series is a series of compounds with the same functional group and similar chemical properties in which each successive MEMBER DIFFERS by `CH_2`. This can be along the length of a carbon chain. The homologous series of straight chained alkenes begins with methane `[CH_4]`, ethene `[C_2H_6]`, propane `[C_3H_8]` butane `[C_4H_10]` and pentane `[C_2H_12]` in this series , successive members differ in mass by an extra methylene bridge `[-CH_2-`unit ] INSERTED in the chain . Thus the MOLECULAR mass of each member differs by 14 ATOMIC mass units . Adjacent members in such a series , such as methane and ethane, are known as " adjacent homologues. "

Discussion

1552.	Which of the following concentrations of the electrolyte corresponds to maximum conductivity ?
Answer» 1 M HCl 1 M `HNO_(3)` 1 M `HClO_(4)` 1 M `H_(2)SO_(4)` Solution :1M solution of `H_(2)SO_(4)` dissociates to produce 3 moles of ions, whereas 1 M solution of other acids DISSOCIATE to produce 2 moles of ions. Therefore, 1 M `H_(2)SO_(4)` shows maximum conductivity

Discussion

1553.	Write the names of the following compounds : (a) CH_(3)-CH_(2)-underset(Br)underset(\|)CH-CH_(3) (b) CH_(3)-CH_(2)-underset(OH)underset(\|)CH-CH_(2)-CH_(3) ( c ) CH_(3)-CH_(2)-CH_(2)-CHO (d) CH_(3)-underset(O)underset(\|\|)C-CH_(2)-CH_(3) ( e ) CH_(3)-CH_(2)-CH_(2)-underset(O)underset(\|\|)C-OH (f) CH_(3)-CH_(2)-CH_(2)-CH=CH_(2) (g) CH_(3)-CH_(2)-CH_(2)-C-=CH
Answer» SOLUTION :

Discussion

1554.	Which of the following is not a straight chain hydrocarbon ?
Answer» `H_(3)C-CH_(2)-CH_(2)-CH_(2)-underset(CH_(3))underset(\|)CH_(2)` `H_(3)C-CH_(2)-CH_(2)-CH_(2)-CH_(2)-CH_(3)` `H_(2)OVERSET(CH_(3))overset(\|)C-H_(2)C-H_(2)C-underset(CH_(3))underset(\|)(CH_(2)` Solution :COMPOUNDS (a), (b) and (c) can be written as straight chain compounds but compound (d) is reall a branched chain compound.

Discussion

1555.	The rocky impurity associated with an ore is called ______ or __________.
Answer» SOLUTION :GANGUE, MATRIX

Discussion

1556.	What is rancidity ? Mention any two ways by which rancidity can be prevented.
Answer» Solution :The oxidation of oils or fats in a food resulting into BAD SMELL and bad taste is CALLED RANCIDITY . It can be prevented by __ (i) adding anti-oxidants. (ii) flushing with nitrogen GAS.

Discussion

1557.	The scientist who classified elements on the basisof atomic mass .
Answer» SOLUTION :DMITRI MENDELEEV.

Discussion

1558.	Which of the following is obtained by the reduction of methanal ?
Answer» Ethanol `CO_(2)` and `O_(2)` METHANOL All of the GIVEN ANSWER :C

Discussion

1559.	Write the name and molecular formula of an organic compound having its name suffixed with 'ol' and having two carbon atoms in its molecule. Write balanced chemical equation to indicate what happens when this compound is heated with excess conc. H_(2)SO_(4) and the name of main product formed. Also state the role of conc. H_(2)SO_(4) in the reaction.
Answer» SOLUTION :Ethanol, `C_(2)H_(5)OH` `C_(2)H_(5)Oh overset("Conc."H_(2)SO_(4))to underset"ETHENE"(CH_(2))=CH_(2)+H_(2)O` Role of conc. `H_(2)SO_(4)`-It ACT as a dehydrating AGENT.

Discussion

1560.	You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solutions and a basic solution , respectively . If you are given only red litmus paper, how will you identify the contents of each test tube ?
Answer» Solution :(a) Put , the RED litmus paper turn by in each of the THREE TEST tubes. The solution which TURNS the red litmus paper to blue will be a basic solution . Here, the blue litmus paper formed can now be USED to test acidic solution. (b) Put this blue litmus paper in the remaining two test tubes, one by one . The solution which turns the blue litmus paper to red will be the acidic solution. (c) The solution which has no effect on any litmus paper will be neutral and hence , it will be distilled water.

Discussion

1561.	Where we use the phrase -"Like dissolves Like" and explain the meaning of phrase?
Answer» SOLUTION :The phrase "like dissolves like” is often USED for predicting solubility. This expression means that dissolving occurs when similarities exist between the solvent and the solute. For EXAMPLE: COMMON SALT is a polar compound and dissolves readily in polar solvent like water.

Discussion

1562.	Write the definition of displacement reaction. Give one example of it and explain, how is it different from double displacement reaction.
Answer» Solution :The REACTION in which more reactive metal DISPLACES the LESS reactive metal from its COMPOUND is called as displacement reaction. For example, `Fe(s)+CuSO_(4)(aq) to FeSO_(4)(aq) +Cu(s)` This reaction is different than double displacement reaction. In double displacement reaction ions get exchanged in two compounds. For example, `Na_(2)SO_(4)(aq) +BaCl_(2) (aq) to BaSO_(4)(s) +2NaCl(aq)` In short, one ion gets exchanged in displacement reaction, while two ions are exchanged in double displacement reaction.

Discussion

1563.	Write the balanced chemical equation for the following reactions. Zinc + Silver nitrate to Zinc nitrate + silver.
Answer» SOLUTION :`Zn+2AgNO_(3)TOZN(NO_(3))_(2)+2AG`.

Discussion

1564.	The three elements A, B and C with similar properties have atomic masses X, Y and Z respectively.The mass of Y is approximately equal to the average mass of X and Z. What is such an arrangement of elements called as? Give one example of such a set of elements.
Answer» Solution :The ARRANGEMENT of these ELEMENTS is KNOWN as Dobereiner triad. Example: lithium, SODIUM and POTASSIUM.

Discussion

1565.	When crystals of washing soda are left open in air, they lose
Answer» nine molecules of water of CRYSTALLISATION five molecules of water of crystallisation three molecules of water of crystallisation TEN molecules of water of crystallisation Solution :`Na_(2)CO_(3).10H_(2)O OVERSET("air") to Na_(2) CO_(3).H_(2)O`

Discussion

1566.	What is fly ash ?
Answer» Solution :Fly ask is a substance PRODUCED from the burning of COAL. It contains elements LIKE CADMIUM and mercury, and is used to make bricks.

Discussion

1567.	What happens when nitric acid is added to an eggshell ?
Answer» SOLUTION :Eggshells contain calcium CARBONATE . When NITRIC acid is added to it, carbon DIOXIDE gas is evolved. The reaction can be GIVEN as `CaCO_(3) + 2NHO_(3) rarrCa(NO_(3))_2+H_(2)O+CO_(2)`

Discussion

1568.	Why are food cans tins plated instead of zinc plated through zinc is cheaper than tin?
Answer» Solution :TIN is less reactive than ZINC. It is less LIKELY to dissolved in the LIQUID in the food cans. Tin reacts only with powerful acids whereas zinc can easily react EVEN with tomatoes, so it is not safe to store food in zinc plated cans.

Discussion

1569.	Which of the following ions can turn red litmus solution blue ?
Answer» `H^(+)` `OH^(-)` `Cl^(+)` ` O^(2-)` ANSWER :B

Discussion

1570.	Write the formulae of chlorides of Eka-silicon and Eka-aluminium, the elements predicted by Mendeleev.
Answer» Solution :Eka-silicon is identified as germanium (Ge) which is placed in group 4 of Mendeléer.s periodic table. The VALENCY of germanium is 4: so the chemical formula for its CHLORIDE MUST be `GeCI_4`. Eka-aluminium was later identified as GALLIUM (Ga). It is placed in group 3 of the Mendeléev.s periodic table. Hence the valency of gallium is 3 and the formula of chloride would be `GaCl_3`.

Discussion

1571.	Which of the following is (arc) an endothermic process ( cs)? (a) Dilution of sulphuric acid (b) Sublimation of dry ice (c) Condensation of water vapours (d) Evaporation of water
Answer» a and c B only c only b and d Answer :B

Discussion

1572.	What is the periodic trend observed in the variation of atomic radii down a group?
Answer» Solution :While going down the group the atomic radii goes on increasing, this is because new SHELLS are added to the atoms of the elements as we go down from top to bottom in a group. The outermost electron go further and further away from the nucleus, extending the radius and ULTIMATELY ultimately increasing the SIZE of the atom INSPITE of the INCREASED nucler charge.

Discussion

1573.	Which of the following metals is soft in nature?
Answer» platinum iron aluminium SODIUM Solution :Sodium is a SOFT METAL.

Discussion

1574.	When CO_(2) is passed through lime water,it turns…….
Answer» Milky Black red Blue

Discussion

1575.	Which of the following statements is true for acids ?
Answer» a)Bitter and change RED litmus to blue b)Sour and change red litmus to blue c)Sour and change blue litmus to red d)Bitter and change blue litmus to red Solution :Sour and change blue litmus to red

Discussion

1576.	The second homologue of alkyne is
Answer» CH `C_2H_2` `C_2H_4` `C_3 H_4` SOLUTION :`C_3 H_4`

Discussion

1577.	What is the sign of Delta G^(ө) for spontaneous reaction?
Answer» SOLUTION :`DELTA G = -ve`

Discussion

1578.	Write the group and period numbers of oxygen from its electronic configuration (O = 8 = 2, 6).
Answer» Solution :From the electronic configuration of OXYGEN (O = 8 = 2, 6), we find that there are six electrons in its OUTERMOST shell (second shell). Since oxygen is a nonmetal, its group NUMBER = 6 + 10 = 16. Thus, oxygen belongs to group 16 and period 2.

Discussion

1579.	Which did Sommerfel extend Bohr's theory ?
Answer» Solution :Sommerfeld EXTENDED Bohr's to EXPLAIN the fine structure of spectral lines in the ATOMIC spectum of HYDROGEN .

Discussion

1580.	Write the reaction of chlorine with ethyne in the presence of light
Answer» SOLUTION :`HC -= CH + Cl_2 to 2C + 2HCL`

Discussion

1581.	Which of the following is a combustion reaction ?
Answer» BOILING of water Melting of wax Burning of petrol None of these ANSWER :C

Discussion

1582.	Vertical columns of elements in the periodic table are called ____
Answer» ANSWER :GROUPS

Discussion

1583.	Which functional group is present in ketone ?
Answer» `{:("\"),("/"):}C=O` `-COOH` `-CHO` `-OH` ANSWER :A

Discussion

1584.	Whose presence causes the decomposition reaction ? Can it be considered as an endothermic reaction ?
Answer» SOLUTION :Decomposition reaction takes place by ABSORPTION of HEAT or in presence of sunlight or CARRIED out by electrolysis. In decomposition reaction, atoms of reactant molecules ABSORB energy and decompose into small species. Hence, decomposition reaction is considered as an endothermic reaction since heat is absorbed.

Discussion

1585.	Which of the following is a strong base?
Answer» `NH_(4)OH` `CA(OH)_(2)` `AL(OH)_(3)` NaOH Answer :A

Discussion

1586.	Which of the following substances should be added to an acidic solution to make it basic ?
Answer» BAKING SODA SULPHURIC acid Ammonium hydroxide calcium hydroxide Answer :A::C::D

Discussion

1587.	What is an ionic bond?
Answer» Solution :The chemical bond FORMED by the TRANSFER of electrons from one atom to ANOTHER is known as as IONIC bond.

Discussion

1588.	What happens when hydrongen chloride gas is dissolved in water ?
Answer» SOLUTION :It GIVES HYDROGEN IONS in solution .

Discussion

1589.	Which one of the following is a strong acid?
Answer» `CH_(3)COOH` HCl `H_(2)C_(2)O_(4)` `H_(2)CO_(3)` Answer :B

Discussion

1590.	Variable valency in general, exhibited by
Answer» GASEOUS elements s - BLOCK elements non - metals transition elements Answer :D

Discussion

1591.	Write the number of covalent bonds in the molecule of butane, C_(4)H_(10).
Answer» Solution :There are THIRTEEN COVALENT BONDS: `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-H`

Discussion

1592.	What aremetathesisreaction ?
Answer» SOLUTION :WHENTWOCOMPOUNDS REACT, if theirions areinterchangedthenthe REACTIONIS calleddoubledisplacementreactionor ' MetathesisReaction '.

Discussion

1593.	Write the balanced chemical equation and name the products when one mole of ethane reacts with two moles of Cl_2.
Answer» SOLUTION :`underset("ETHANE")(CH_3) - CH_3 + underset("CHLORINE")(2Cl)- Cl to underset("1,2-dichloroethane")(ClCH_2 - CH_2Cl) + underset("hydrogen chloride")(2HCL)`

Discussion

1594.	Which ion moves towards the cathode ?
Answer» SOLUTION :`NI^(2+)`

Discussion

1595.	The structural formulae of hvdrocarbons are given in Column-A and their uses are given in Column-B.
Answer» (a) USED as FUEL (b) dry CLEANING SOLVENT for lacquers Preparation of MOTH balls. Answer :B

Discussion

1596.	Which of the following is the valence shell for the elements of second period of the modern periodic table ?
Answer» M-shell K-shell N-shell L-shell

Discussion

1597.	Which of the following processes is used to separate the components of a mixture of sulphur and charcoal ?
Answer» Evaporation Distillation Filtration Dissolution in CARBON DISULPHIDE ANSWER :C

Discussion

1598.	Write one example of each of the following : (i) Most malleable metal and most ductile metals. The best condcutor of heat and the poorest conductor of heat. (iii) A metal with highest melting point and a metal with lowest melting point.
Answer» SOLUTION :(i) Gold and SILVER are most MALLEABLE and ductile metal. (ii) Silver is the best conductor of HEAT and lead is the poorest conductor of heat. (iii) Metal with highest melting POINT - Tungsten,iron. Metal with lowest melting point - Gallium Caesium.

Discussion

1599.	Which of the following is not a homogeneous mixture ?
Answer» Aqueous solution ofsugar Aqeous solution of COMMON salt Oil mixed with water Limewater ANSWER :C

Discussion

1600.	Which of the following statements is not a correct statement about the trends when going from left to right across the periods of the periodic table?
Answer» The elements BECOME less METALLIC in nature. The number of VALENCE electrons increases. The atoms LOSE their electrons more easily. The oxide become more acidic. Answer :C

Discussion

Explore topic-wise InterviewSolutions in .

What is a homologous series? Explain with an example .

Which of the following concentrations of the electrolyte corresponds to maximum conductivity ?

Which of the following is not a straight chain hydrocarbon ?

The rocky impurity associated with an ore is called ______ or __________.

What is rancidity ? Mention any two ways by which rancidity can be prevented.

The scientist who classified elements on the basisof atomic mass .

Which of the following is obtained by the reduction of methanal ?

You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solutions and a basic solution , respectively . If you are given only red litmus paper, how will you identify the contents of each test tube ?

Where we use the phrase -"Like dissolves Like" and explain the meaning of phrase?

Write the definition of displacement reaction. Give one example of it and explain, how is it different from double displacement reaction.

Write the balanced chemical equation for the following reactions. Zinc + Silver nitrate to Zinc nitrate + silver.

The three elements A, B and C with similar properties have atomic masses X, Y and Z respectively.The mass of Y is approximately equal to the average mass of X and Z. What is such an arrangement of elements called as? Give one example of such a set of elements.

When crystals of washing soda are left open in air, they lose

What is fly ash ?

What happens when nitric acid is added to an eggshell ?

Why are food cans tins plated instead of zinc plated through zinc is cheaper than tin?

Which of the following ions can turn red litmus solution blue ?

Write the formulae of chlorides of Eka-silicon and Eka-aluminium, the elements predicted by Mendeleev.

Which of the following is (arc) an endothermic process ( cs)? (a) Dilution of sulphuric acid (b) Sublimation of dry ice (c) Condensation of water vapours (d) Evaporation of water

What is the periodic trend observed in the variation of atomic radii down a group?

Which of the following metals is soft in nature?

When CO_(2) is passed through lime water,it turns…….

Which of the following statements is true for acids ?

The second homologue of alkyne is

What is the sign of Delta G^(ө) for spontaneous reaction?

Write the group and period numbers of oxygen from its electronic configuration (O = 8 = 2, 6).

Which did Sommerfel extend Bohr's theory ?

Write the reaction of chlorine with ethyne in the presence of light

Which of the following is a combustion reaction ?

Vertical columns of elements in the periodic table are called ____

Which functional group is present in ketone ?

Whose presence causes the decomposition reaction ? Can it be considered as an endothermic reaction ?

Which of the following is a strong base?

Which of the following substances should be added to an acidic solution to make it basic ?

What is an ionic bond?

What happens when hydrongen chloride gas is dissolved in water ?

Which one of the following is a strong acid?

Variable valency in general, exhibited by

Write the number of covalent bonds in the molecule of butane, C_(4)H_(10).

What aremetathesisreaction ?

Write the balanced chemical equation and name the products when one mole of ethane reacts with two moles of Cl_2.

Which ion moves towards the cathode ?

The structural formulae of hvdrocarbons are given in Column-A and their uses are given in Column-B.

Which of the following is the valence shell for the elements of second period of the modern periodic table ?

Which of the following processes is used to separate the components of a mixture of sulphur and charcoal ?

Write one example of each of the following : (i) Most malleable metal and most ductile metals. The best condcutor of heat and the poorest conductor of heat. (iii) A metal with highest melting point and a metal with lowest melting point.

Which of the following is not a homogeneous mixture ?

Which of the following statements is not a correct statement about the trends when going from left to right across the periods of the periodic table?

The rocky impurity associated with an ore is called or ____.