8881 + Interview Questions in Chemistry in Class 10 Page 98 InterviewSolution

4851.	In spite of the addition of cryolite and fluorspar to alumina only Al^(+3)andO^(-2) ions are discharged at their respective electrodes. Justify.
Answer» Solution :Cryolite `(Na_(3)AlF_(6))` and fluorspar `(CaF_(2))` are added to alumina to reduce its melting point. `Al^(+3)` discharges preferentially over `NA^(+)andCa^(+3)` at cathode, because of lower discharge potential of `Al^(+3)` than `Na^(+)andCa^(+)` and at ANODE, `O^(-2)` gets DISCHARGED due to its lower discharge potential than `F^(-)` and is evolved as `O_(2)`, which reacts with carbon anode forming `CO_(2)` gas.

Discussion

4852.	In soap and detergent, non-polar tail is attracted towards ………………. And an anionic head is attracted towards ……………….. .
Answer» STAIN, GLYCEROL WATER molecules, stain stain, water molecules water molecules, glycerol Answer :C

Discussion

4853.	In Rtherfor'ds experiment most of the alpha particles were
Answer» PASSED undeflected deflected thrown back absorbed Answer :A

Discussion

4854.	In .......... process, solubility increases with increase in temperature.
Answer» EXOTHERMIC ENDOTHERMIC isothermic ADIABATIC SOLUTION :endothermic

Discussion

4855.	In ………. Process , solubility increases with ……….. In temperature
Answer» SOLUTION :ENDOTHERMIC, INCREASE

Discussion

4856.	In ......... process, solubility decreases with increase in temperature.
Answer» EXOTHERMIC adiabatic endothermic ISOTHERMIC SOLUTION :exothermic

Discussion

4857.	In PCl_(5) molecule the two equivalent axial P – Clbonds are...............than three equivalent equatorial P – Cl bonds.
Answer» SOLUTION : LONGER

Discussion

4858.	In organic compound, which part largely determine its physical and chemical properties?
Answer» SOLUTION :The alkyl part (carbon chain) of an ORGANIC compound DETERMINES its physical properties whereas the functional GROUP determines its CHEMICAL properties.

Discussion

4859.	In order to prevent rancidity of oils in foodstuff , an _____ added.
Answer» SOLUTION :antioxdant

Discussion

4860.	In order to form a compound, which of the following functional group possess minimum three carbon atoms ?
Answer» `-COOH` `-CHO` `{:("\"),("/"):}C=O` `-C-O-` ANSWER :C

Discussion

4861.	In one of the industrial processes used for manufacture of sodium hydroxide, a gas X is formed as byproduct. The gas X reacts with lime water to give a compound Y which is used as a bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.
Answer» Solution :(i) X= CHLORINE gas Y= Calcium OXYCHLORIDE `(ii) Ca(OH)_2+Cl_2 toCaOCl_2+H_2O` (Dry SLAKED LIME) (Chlorine) (Calcium oxychloride) (Bleaching agent) (WATER)

Discussion

4862.	In one of the industrial process used for manufacture of sodium hydroxide, a gas X is formed as by - product . The gas X reacts with lime water to give a compound Y which is used as bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.
Answer» Solution :In the manufacture of sodium hydroxide , hydrogen gas and chlorine gas (X) are formed as by - products . When chlorine gas (X) reacts with lime water , if form CALCIUM oxychloride (bleaching powder ) . Y The reactions are `2NaCl(AQ)+2H_(2)O(l) rarr2NaOH(aq)+Cl_(2)(g)+H_(2)(g)` `X-Cl_(2)`(Chlorine gas) `underset("Lime water")(Ca(OH)_(2))(s)+Cl_(2)(g)rarrCaOCl_(2)(s)+H_(2)O(l)` Y - Calcium oxychloride (bleaching powder)

Discussion

4863.	In nature, metal A is found in a free state while metal B is found in the form of its compounds. Which of these two will be nearer to the top of the activity series of metals?
Answer» SOLUTION :METAL B will be nearer to the top of the activity SERIES of metals as it is so REACTIVE that it is found in combined state.

Discussion

4864.	In Mendeleev's periodic table, gaps were left for the elements to be discovered later. Which of the following elements found a place in the periodic table later?
Answer» Be Ge Si Se

Discussion

4865.	In Lothar Meyer curve, the halogens occupy positions on the
Answer» desending PORTION of the curve ascending portion of the curve Peak positionof THECURVE no FIXED POSITION on the curve Answer :B

Discussion

4866.	In L-D converter pure oxygen is used for oxidation while in Bessemer process air is used for the same purpose. Which of these is better and why?
Answer» Solution :Usage of OXYGEN is better because of the FOLLOWING REASONS: (i) Nitrgen in air makes the steel brittle. (II) Nitrogen carries away a lot of HEAT and hence attaining the required temperature is tedious.

Discussion

4867.	In IUPAC name, the carbon skeleton of a compound is represented by………………
Answer» SOLUTION :ROOT WORD

Discussion

4868.	In IUPAC name, the carbon skeleton of a compound is represented by _______ ( root /word/prefix/suffix) .
Answer» SOLUTION :ROOT WORD

Discussion

4869.	In iron the differentiating electron enters into the orbitals of a penultimate shell
Answer» ANSWER :TURE

Discussion

4870.	In how many groups and periods, the Modern Periodic Table of elements is divided?
Answer» SOLUTION :18 GROUPS and 7 PERIODS

Discussion

4871.	In how many forms did the earlier Indian philosophers classify matter?
Answer» 2 6 7 5 Solution :5

Discussion

4872.	In his periodic table, Mendeleev arranged all the then known 63 elements in the order of increasing atomic masses in horizontal rows but in such a way that elements having similar properties came directly under one another in the same vertical column. In the classification of the then known elements, Mendeleev was guided mainly by two factors. In order to make sure that the elements having similar properties fall in the same vertical column, Mendeleev left some gaps in his periodic table. Though leaving gaps in the periodic table was considered to be a drawback of his classification of elements at that time but Mendeleev was firm on his decision. Answer the following questions : What values were displayed by Mendeleev in presenting his classification of elements ?
Answer» Solution :The VARIOUS values displayed by Mendeleev were (i) self-confidence, (II) COURAGE, (iii) foresight and (iv) PROPHECY.

Discussion

4873.	In his periodic table, Mendeleev arranged all the then known 63 elements in the order of increasing atomic masses in horizontal rows but in such a way that elements having similar properties came directly under one another in the same vertical column. In the classification of the then known elements, Mendeleev was guided mainly by two factors. In order to make sure that the elements having similar properties fall in the same vertical column, Mendeleev left some gaps in his periodic table. Though leaving gaps in the periodic table was considered to be a drawback of his classification of elements at that time but Mendeleev was firm on his decision. Answer the following questions : For what purpose were some gaps left by Mendeleev in his periodic table? Does the modern periodic table also have the gaps left by Mendeleev?
Answer» SOLUTION :These gaps were left for the ELEMENTS which had not been discovered at that TIME. He thought that these elements would be discovered later in future. The modern PERIODIC table does not have any gaps.

Discussion

4874.	In his periodic table, Mendeleev arranged all the then known 63 elements in the order of increasing atomic masses in horizontal rows but in such a way that elements having similar properties came directly under one another in the same vertical column. In the classification of the then known elements, Mendeleev was guided mainly by two factors. In order to make sure that the elements having similar properties fall in the same vertical column, Mendeleev left some gaps in his periodic table. Though leaving gaps in the periodic table was considered to be a drawback of his classification of elements at that time but Mendeleev was firm on his decision. Answer the following questions : What are the vertical columns of Mendeleev's periodic table known as ? How many vertical columns were there in Mendeleev's periodic table ?
Answer» Solution :The vertical columns of Mendeleev.s periodic table are CALLED groups. There were EIGHT groups in Mendeleev.s periodic table.

Discussion

4875.	In his periodic table, Mendeleev arranged all the then known 63 elements in the order of increasing atomic masses in horizontal rows but in such a way that elements having similar properties came directly under one another in the same vertical column. In the classification of the then known elements, Mendeleev was guided mainly by two factors. In order to make sure that the elements having similar properties fall in the same vertical column, Mendeleev left some gaps in his periodic table. Though leaving gaps in the periodic table was considered to be a drawback of his classification of elements at that time but Mendeleev was firm on his decision. Answer the following questions : What were the two main guiding factors for Mendeleev in the classification of the then known elements ?
Answer» Solution :The two main guiding factors for MENDELEEV in the classification of the then known elements were (i) increasing order of atomic MASSES, and (II) grouping TOGETHER the elements having similar properties.

Discussion

4876.	In his periodic table, Mendeleev arranged all the then known 63 elements in the order of increasing atomic masses in horizontal rows but in such a way that elements having similar properties came directly under one another in the same vertical column. In the classification of the then known elements, Mendeleev was guided mainly by two factors. In order to make sure that the elements having similar properties fall in the same vertical column, Mendeleev left some gaps in his periodic table. Though leaving gaps in the periodic table was considered to be a drawback of his classification of elements at that time but Mendeleev was firm on his decision. Answer the following questions : What were the similar properties used by Mendeleev to classify the then known elements into vertical columns ?
Answer» SOLUTION :The similar properties used by MENDELEEV to classify the ELEMENTS into VERTICAL columns were the similar formulae of their oxides and hydrides.

Discussion

4877.	In his periodic table, Mendeleev arranged all the then known 63 elements in the order of increasing atomic masses in horizontal rows but in such a way that elements having similar properties came directly under one another in the same vertical column. In the classification of the then known elements, Mendeleev was guided mainly by two factors. In order to make sure that the elements having similar properties fall in the same vertical column, Mendeleev left some gaps in his periodic table. Though leaving gaps in the periodic table was considered to be a drawback of his classification of elements at that time but Mendeleev was firm on his decision. Answer the following questions : What are the horizontal rows of Mendeleev's periodic table known as ? How many horizontal rows of elements were there in Mendeleev's periodic table ?
Answer» SOLUTION :The horizontal rows of ELEMENTS in the Mendeleev.s periodic table are called PERIODS. There were SEVEN periods in Mendeleev.s periodic table.

Discussion

4878.	In his periodic table, Mendeleev arranged all the then known 63 elements in the order of increasing atomic masses in horizontal rows but in such a way that element having similar properties came directly under one another in the same vertical column. In the classification of the then known elements, Mendeleev was guided mainly by two factors. In order to make sure that the elements having similar properties fell in the same vertical column, Mendeleev left some gaps in his periodic table. Though the leaving of gaps in the periodic table was considered to be a big drawback of his classification of elementsat that time but Mendeleev stuck to his decision. (a) What are the horizontal rows of Mendeleev's periodic table known as? How many horizontal rows of elements were there in Mendeleev's original periodic table? (b) What are the vertical columns of Mendeleev's periodic table known as? How many vertical columns were there in Mendeleev's original periodic table? (c) What were the similar properties used by Mendeleev to classify the then known elements into vertical columns? (d) What were the two main guiding factors for Mendeleev in the classification of the then known elements? (e)For what purpose were some gaps left by Mendeleev in his periodic table ? Does the modern periodic table also have the gaps left by Mendeleev? Explain your answer. (f) What values were displayed by Mendeleev in presenting his classification of elements?
Answer» Solution : (a) The horizontal rows of elements in the periodic table are called periods. There were seven periods in Mendeleev's original periodic table. (b) The VERTICAL columns of Mendeleev's periodic are called groups. There were eight groups in Mendeeev's original periodic table. (c) The similar properties used by Mendeleev to classify the element into vertical columns (or groups) were the similar FORMULAE of their oxides and hydrides. (d) The two main guiding actors for Mendeleev in the classification of the then known elements wer: (i) increasing atomic masses, and (ii) grouping together of elements having similar properties. ltbr. (e) These gaps were left for the elements which had not been discovered at that time. Mendeleev thought that these elements would be discovered LATER on in future. The modern periodic table does not have any gaps because new elements were discovered later on which were placed correctly in the gaps left by Mendeleev. (f) The various values displayed by Mendeleev were (i) Self confidence (because he had full faith in his WORK on the classification of elements) (ii) Courage (to leave gaps in his periodic table for the then unknown elements )(iii) foresight (to tell in advance that more elements would be discovered later on which will fill the gaps), and (IV) Prophecy (to predict the properties of the then unknown elements).

Discussion

4879.	In halogens (group 17) the atomic radius of chlorine is greater than the atomic radius of fluorine. Give reason.
Answer» SOLUTION :Because in a chlorine atom (CL = 2, 8, 7) the outermost electrons are in the third shell (M-shell, n = 3), whereas in a fluorine atom (F = 2, 7) the outermost electrons are in the second shell (L-shell, n = 2).

Discussion

4880.	In Hall's process of electrolytic reduction of alumina . Name the electrolyte .
Answer» Solution :Electrolyte : PURE ALUMINA + molten CRYOLITE + FLUORSPAR.

Discussion

4881.	In Hall's process of electrolytic reduction of alumina . Name the Cathode .
Answer» SOLUTION :CATHODE : Iron TANK LINKED with GRAPHITE .

Discussion

4882.	In Hall's process of electrolytic reduction of alumina . Name the Anode .
Answer» SOLUTION :ANODE : A BUNCH of graphiterodssuspended in MOLTENELECTROLYTE .

Discussion

4883.	In group 17 of the periodic table, fluorine is more reactive than chlorine, and chlorine is less reactive than fluorine. Give reasons.
Answer» Solution :(i) The valence shell of fluorine (F = 2, 7) is L-shell (n = 2). Its atomic radius is small. It has a greater tendency to gain one ELECTRON in its valence shell. Therefore, fluorine is more reactive than CHLORINE. (ii) The valence shell of chlorine (Cl = 2, 8, 7) is M-shell (n = 3). Its radius is large. Its tendency to gain an electron is small as COMPARED to fluorine. Therefore, chlorine is less reactive than fluorine.

Discussion

4884.	In group 1 of the periodic table three elements X, Y and Z have atomic radii 133 pm, 95 pm and 65 pm respectively. Giving a reason, arrange them in the order of increasing atomic number in the group.
Answer» SOLUTION :Z Y X, because in a group the atomic SIZE increases with INCREASE in the atomic NUMBER.

Discussion

4885.	In group 1 the atomic radius of sodium is greater than the atomic radius of lithium. Give reason.
Answer» SOLUTION :Because in a SODIUM atom (Na = 2,8, 1) the outermost electron is in the third shell (M-shell, n = 3), whereas in a LITHIUM atom (Li = 2, 1) the outermost electron is in the second shell (L-shell, n = 2).

Discussion

4886.	In graphite, the different layers are held together by
Answer» IONIC bonding covalent bonding VAN DER WAALS FORCES metallic bonding Solution :van der Waals forces

Discussion

4887.	In group 1 (alkali metals), sodium is more reactive than lithium, or lithium is less reactive than sodium. Give reason.
Answer» Solution :(i) The valence shell of SODIUM (2, 8, 1) is M-shell (n = 3). Its radius is LARGE. It is easy to remove its valence electron. Therefore, sodium is more reactive than LITHIUM. (ii) The valence shell of lithium (2, 1) is L-shell (n = 2). Its radius is SMALL and the removal of valence electron is difficult as compared to sodium. Therefore, lithium is less reactive than sodium.

Discussion

4888.	In general the numebr of electrons in the outermost shell of a metal atom is
Answer» 1 1 to 3 5 to 8 8 Answer :B

Discussion

4889.	In forming compound AB, an electron is transferred from A to B then
Answer» A is divalent B is oxidised A and B are covalently bonded the compound AB is electrovalent Solution :The bond FORMED by the TRANSFER of electron is known as electrovalent or ionic bond.

Discussion

4890.	In electrovalency,
Answer» molecules LOSE electrons forming atoms molecules gain electrons forming atoms atons share electrons atoms lose or gain electrons forming ions SOLUTION :Electrovalency is the NUMBER of electrons LOST or gained by an atom.

Discussion

4891.	In comparison with sodium salts, ammonium salts are more soluble in water. Explain.
Answer» SOLUTION :(i) requisite of a SUBSTANCE to be SOLUBLE in water (II) type of forces of attraction in between the compounds of NACL and `NH_(4)Cl` (iii) effect of this on solubility

Discussion

4892.	In cell representation, oxidationhalf -cell is represented on the _______
Answer» ANSWER :left-hand SIDE

Discussion

4893.	In calcination and roasting, volatile impurities are removed.
Answer» ANSWER :1

Discussion

4894.	In Bessemer converter ______ is removed as phosphate slag.
Answer» ANSWER :PHOSPHORUS

Discussion

4895.	In aqueous solution , ethanoic acid is _______ ionised .
Answer» SOLUTION :partically

Discussion

4896.	In an .................. process, solubility decreases with ................. in temperature.
Answer» SOLUTION :EXOTHERMIC, INCREASE

Discussion

4897.	In an organic compound, which parts largely determine it s physical and chemical properties?
Answer» Solution :The alkyl PART (carbon chain) of an ORGANIC compound determines its PHYSICAL properties whereas the functional GROUP determines its CHEMICAL properties.

Discussion

4898.	In an experiment to test the pH of a given sample using pH paper, four students recorded the followig observations : Which one of the observation in correct ?
Answer» i ii III iv Solution :iii

Discussion

4899.	In an exothermic process, solubility decreases with increase in temperature.
Answer» ANSWER : TRUE

Discussion

4900.	In an endothermic process, solubility decreases with increase in temperature.
Answer» Solution :Correct STATEMENT: In an ENDOTHERMIC process, SOLUBILITY increases with increase in TEMPERATURE.

Discussion

Explore topic-wise InterviewSolutions in .

In spite of the addition of cryolite and fluorspar to alumina only Al^(+3)andO^(-2) ions are discharged at their respective electrodes. Justify.

In soap and detergent, non-polar tail is attracted towards ………………. And an anionic head is attracted towards ……………….. .

In Rtherfor'ds experiment most of the alpha particles were

In .......... process, solubility increases with increase in temperature.

In ………. Process , solubility increases with ……….. In temperature

In ......... process, solubility decreases with increase in temperature.

In PCl_(5) molecule the two equivalent axial P – Clbonds are...............than three equivalent equatorial P – Cl bonds.

In organic compound, which part largely determine its physical and chemical properties?

In order to prevent rancidity of oils in foodstuff , an _____ added.

In order to form a compound, which of the following functional group possess minimum three carbon atoms ?

In one of the industrial processes used for manufacture of sodium hydroxide, a gas X is formed as byproduct. The gas X reacts with lime water to give a compound Y which is used as a bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.

In one of the industrial process used for manufacture of sodium hydroxide, a gas X is formed as by - product . The gas X reacts with lime water to give a compound Y which is used as bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.

In nature, metal A is found in a free state while metal B is found in the form of its compounds. Which of these two will be nearer to the top of the activity series of metals?

In Mendeleev's periodic table, gaps were left for the elements to be discovered later. Which of the following elements found a place in the periodic table later?

In Lothar Meyer curve, the halogens occupy positions on the

In L-D converter pure oxygen is used for oxidation while in Bessemer process air is used for the same purpose. Which of these is better and why?

In IUPAC name, the carbon skeleton of a compound is represented by………………

In IUPAC name, the carbon skeleton of a compound is represented by _______ ( root /word/prefix/suffix) .

In iron the differentiating electron enters into the orbitals of a penultimate shell

In how many groups and periods, the Modern Periodic Table of elements is divided?

In how many forms did the earlier Indian philosophers classify matter?

In halogens (group 17) the atomic radius of chlorine is greater than the atomic radius of fluorine. Give reason.

In Hall's process of electrolytic reduction of alumina . Name the electrolyte .

In Hall's process of electrolytic reduction of alumina . Name the Cathode .

In Hall's process of electrolytic reduction of alumina . Name the Anode .

In group 17 of the periodic table, fluorine is more reactive than chlorine, and chlorine is less reactive than fluorine. Give reasons.

In group 1 of the periodic table three elements X, Y and Z have atomic radii 133 pm, 95 pm and 65 pm respectively. Giving a reason, arrange them in the order of increasing atomic number in the group.

In group 1 the atomic radius of sodium is greater than the atomic radius of lithium. Give reason.

In graphite, the different layers are held together by

In group 1 (alkali metals), sodium is more reactive than lithium, or lithium is less reactive than sodium. Give reason.

In general the numebr of electrons in the outermost shell of a metal atom is

In forming compound AB, an electron is transferred from A to B then

In electrovalency,

In comparison with sodium salts, ammonium salts are more soluble in water. Explain.

In cell representation, oxidationhalf -cell is represented on the _______

In calcination and roasting, volatile impurities are removed.

In Bessemer converter ______ is removed as phosphate slag.

In aqueous solution , ethanoic acid is _______ ionised .

In an .................. process, solubility decreases with ................. in temperature.

In an organic compound, which parts largely determine it s physical and chemical properties?

In an experiment to test the pH of a given sample using pH paper, four students recorded the followig observations : Which one of the observation in correct ?

In an exothermic process, solubility decreases with increase in temperature.

In an endothermic process, solubility decreases with increase in temperature.