InterviewSolution
Saved Bookmarks
InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Generally, non-metals are not lustrous. Which of the following non-metals is lustrous? A. SulphurB. PhosphorusC. NitrogenD. Iodine. |
|
Answer» Correct Answer - D Iodine is lustrous. |
|
| 52. |
When ammonia reacts with excess chlorine it formsA. `NH_4CI+N_2`B. `N_2+HCI`C. `NOCI+HCI`D. `NCI_3+HCI` |
|
Answer» Correct Answer - A `underset("excess")(NH_3+3Cl_2)to NCI_3+2HCI` |
|
| 53. |
Why is titanium called a strategic metal ? Mention two of its properties which make it so special. |
|
Answer» Titanium is called strategic metal because it is used for making certain war equipments. The properties which make the metal so special are : (i) It is light in weight but at the same time stronger than the other metals. (ii) It is not affected by corrosion even if kept in the open for a very long time. |
|
| 54. |
The two metals which can be extracted just by heating their sulphides in air are:A. sodium and copperB. copper and aluminiumC. potassium and zincD. mercury and copper |
|
Answer» Correct Answer - D Correct Answer - d |
|
| 55. |
An important ore of zinc metal is:A. calamineB. cupriteC. pyrolusiteD. haematite |
|
Answer» Correct Answer - A Correct Answer - a |
|
| 56. |
Phosphorous reacts with air and forms `P_2O_5`. |
|
Answer» Correct Answer - True N/A |
|
| 57. |
Which of the follwoing changes takes place during the process of calcination of an ore?A. thermal decomposition of ore takes placeB. the mass become porousC. moisture is removedD. all the above |
|
Answer» Correct Answer - A During calcination, the thermal decompostion of an ore takes place, mass becomes porous and moisture is removed. |
|
| 58. |
A common metal which is highly resistant to corrosion is:A. ironB. copperC. aluminiumD. magnesium |
|
Answer» Correct Answer - C Correct Answer - c |
|
| 59. |
Name two metals which are highly resistant to corrosion. |
| Answer» Aluminium and Zinc. | |
| 60. |
Give reason for the following (i) Iron grills are frequently painted. (ii) Gold ornaments retain their lustre even after several years of use. |
|
Answer» (i) Iron metal easily gets rusted by air containing moisture and oxygen. Therefore, iron grills are frequently painted with rust proof paints. (ii) Gold is a noble metal and is not affected by chemicals or by air. Therefore, gold ornaments retain their lustre even after several years. |
|
| 61. |
A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used? |
| Answer» The man had actually used the solution of aqua regia (mixture of conc. HCl and conc. `HNO_(3)` in the ratio of 3 : 1 by volume) which has dissolved gold forming soluble auric chloride `(AuCl_(3))`. Since gold actually reacted, there was a loss in weight of the gold bangles. With the removal of the dull layer of gold from the surface, there was original shine on the bangles. | |
| 62. |
Which one of the following four metals would be displaced from the solution of its salts by other three metals? A. MgB. AgC. ZnD. Cu |
|
Answer» Correct Answer - b Silver (Ag) metal would be displaced from the solution of its salts by other three metals because Ag is less reactive than Mg,Zn and Cu. |
|
| 63. |
Asseration : Diamond is a good condutor of heat. Reason : In diamond each carbon atom is bonded strongly to four other carbon atoms.A. Both A and R are true and R is the correct explanation for A.B. Both A and R are true but R is the correct explanation for A.C. A is true but R is false.D. A is false but R is true. |
|
Answer» Correct Answer - A In diamond each carbon atom is bonded to four other carbon atoms and foroming rigid three -dimensional structure. Hence , it is a good conductor of heat. |
|
| 64. |
Epsom salt isA. `MgSO_4.7H_2O`B. `KCI.MgCI_2.6H_2O`C. `Na_AIF_6`D. `CaSO_4.2H_2O` |
|
Answer» Correct Answer - A Epsom salt is `MgSO_4.7H_2O` |
|
| 65. |
Different stages involved in the manufacture of hydrogen gas by Bosch process are given below. Arrange them in the correct sequence. (1) removal of unoxidised CO (2) preparation of water gas (3) removal of ` CO_2` (4) removal of water vapour (5) removal of CO.A. 35421B. 34215C. 25341D. 24153 |
|
Answer» Correct Answer - A (i) preparation of water gas. (ii) removal of CO (iii) removal of `CO_2` (iv) removal of water vapour (v) removal of unoxidised CO |
|
| 66. |
Different stages involved in the nitrogen cycle are given below. Arrange them in correct sequence starting from nitrates. (1) conversion of animal protein to excretory product (2) conversion of ammonia to nitrites (3) conversion of plant protein to animal protein (4) conversion of nitrites to nitrites (5) conversion of nitrates to plant protein (6) conversion of excretroy product to ammoniaA. 425163B. 324165C. 562431D. 531624 |
|
Answer» Correct Answer - A (i) conversion of nitrates to plant protein (ii) conversion of plant protein to animal protein (iii) conversion of animal protein to excretory product (iv) conversion of excretory product of ammonia (v) conversion of ammonia to nitrates (vi) conversion of nitrites to nitrates. |
|
| 67. |
General metallurgical process are given below. Arrange them in correct sequence. (1) conversion of ore to oxide. (2) refining (3) dressing of ore (4) extraction of metal (5) concentration of oreA. 51423B. 35142C. 45321D. 25341 |
|
Answer» Correct Answer - A (i) dressing of ore (ii) concentration of ore (iii) conversion of ore to oxide (iv) extration of metal (v) refining |
|
| 68. |
A metal A, which is used in thermite process, when heated with oxygen gives an oxide B, which is amphoteric in nature. Identify A and B. Write down the reactions of oxide B with HCl and NaOH. |
|
Answer» Matel A is aluminium (Al) which is used in thermite process. Al reacts with oxygen to from aluminium oxide `Al_(2)O_(3)` (B) which is amphoteric in nature. `4Al+3O_(2)tounderset((B))(2Al_(2)O_(3)(s))` `(i)underset("Aluminium oxide")(Al_(2)O_(3)(s))+underset("Hydrochioric acid")(6HCl(aq))tounderset("Aluminium chloride")(2AlCl_(3)(aq))+3H_(2)O(l)` `(ii)underset("Aluminium oxide")(Al_(2)O_(3))+underset("Hydrochioric acid")(2NaOH(aq))tounderset("Sodium aluminate")(2NaAlO_(2)(aq))+3H_(2)O(l)` |
|
| 69. |
What happens when (a) `ZnCO_(3)` is heated in the absence of oxygen? (b) a mixture of `Cu_(2)O" and "Cu_(2)S` is heated? |
|
Answer» (a) A mixture of ZnO(s) and `CO_(2)` is formed `ZnCO_(3) overset("heat")rarrZnO(s) + CO_(2)(g)` (b) A mixture of copper and `SO_(2)` is formed. `2Cu_(2)O(s) + Cu_(2)S(s) overset("heat")rarr 6Cu(s) + SO_(2)(g)`. |
|
| 70. |
Which metal is used in amalgams ? |
| Answer» Mercury (Hg) is used in amalgams that are also alloys in nature. | |
| 71. |
of the three metals X, Y and Z, X reacts with cold water, Y with hot water and Z with steam only. Identify X, Y and Z and also arrange them in order of increasing reactivity. |
|
Answer» The answer is based on the relative positions of the metals in the reactivity series. The activity with water decreases down the series. • Metals X is Na or K • Metal Y is Mg or Ca • Metal Z is Al or Fe. Order of increasing reactivity : `Z lt Y lt X`. |
|
| 72. |
The chief ore of aluminium isA. cinnabarB. calamineC. bauxiteD. pyrolusite |
|
Answer» Correct Answer - C Correct Answer - c |
|
| 73. |
When an object made of metal A is kept in air for a considerable time, it loses its shine and becomes almost black due to the formation fo a layer of substance B. when an object made of another metal C is kept in damp air for a considerable time, it gets covered with a green layer of substance D. Metal A is the best conductor of electricity whereas metal C is the next best conductor of electricity. (a) What is metal A? (b) What is metal C? (c) name the substance B. (d) name the substance D. (e) What type of chemcial can be used to remove the green layer from metal C and clean it? Why? |
| Answer» (a) Silver (b) copper (c) silver sulphide (d0 Basic copper carbonate (e) dilute acid solution, The acid solution dissolves green coloured basic copper carbonate present on the corroded copper object | |
| 74. |
In an electrolytic tank, aluminium metal is being extracted by the electrolysis of molten aluminium oxide using carbon electrodes. It is observed that one of the carbon electrodes is gradually burnt aay and has to be replaced. (a) Which carbon electrode (cathode or anode) is burnt away? (b) why is this carbon electrode burnt away? |
| Answer» (a0 Positively charged carbon electrode (anode) (b) because oxygen produced during the electrolysis of molten aluminium oxide reacts gradually with the carbon of carbon anode to form carbon dioxide gas | |
| 75. |
Which of the following reactions will not occur? Why not? (a). `MgSO_(4)(aq)+Cu(s)toCuSO_(4)(aq)+Mg(s)` (b). `CuSO_(4)(aq)+Fe(s)toFeSO_(4)(aq)+Cu(s)` (c). `MgSO_(4)(aq)+Fe(s)toFeSO_(4)(aq)+Mg(s)`. |
|
Answer» Reaction (a) will not occur because Cu is less reactive than Mg, Reaction (c). Will also not occur because Fe is less reactive than Mg |
|
| 76. |
Name a metal other than aluminium that is covered with a layer of oxide film. |
| Answer» Iron (Fe) is also covered with a layer of its oxide `(Fe_(2)O_(3))` when kept exposed to air for a long time. | |
| 77. |
From the options given along the side of each statement, select the most appropriate. (i) A metal that gets covered with a protective film of its oxide : Al, Cu, Ag (ii) A metal which burns in air will golden flame : Zn, K, Na (iii) A metal which can displace hydrogen from boiling water as well as steam : K, Zn, Fe (iv) A metal that does not react with air at room temperature. : Na, Mg, Ca |
| Answer» (i) Al (ii) Na (iii) Zn (iv) Mg. | |
| 78. |
Which among the following alloys contain mercury as one of its constituents?A. Stainless steelB. German silverC. SolderD. Zinc amalgam. |
|
Answer» Correct Answer - D All amalgams contain mercury as one of their constituents. |
|
| 79. |
Bleaching action of `SO_2` is reversible. Justify. |
| Answer» Sulphur dioxide on reaction with moisture or water produce nascent hydrogen which helps in the bleaching action. | |
| 80. |
A non-metal X exists in two different forms Y and Z. Y is hardest natural substance, whereas Z is a good conductor of electricity. Identify X, Y and Z. |
| Answer» Since 'Y' is the hardest occuring non-metal, it is diamond. The non-metal 'X' is carbon. Y is the crystalline allotropic form of carbon. The other allotropic form Z which is a good conductor of electricity is graphite. | |
| 81. |
(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» (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. |
|
| 82. |
(a). State one use each of the followign non-metals: Hydrogen, Carbon (as Graphite), Nitrogen, Sulphur (b). Name the metal which is used in making thermomenters. |
| Answer» Correct Answer - (b) Mercury | |
| 83. |
Which of the following pairs will give displacement reaction? (a) `NaCl` solution and copper metal (b) `MgCl_(2)` solution and aluminium metal (c) `FeSO_(4)` solution and silver metal (d) `AgNO_(3)` solution and copper metal |
| Answer» (d) `AgNO_(3)` solutions and copper metal | |
| 84. |
Which of the following can undergo a chemical reaction?A. `MgSO_(4)+Fe`B. `ZnSO_(4)+Fe`C. `MgSO_(4)+Pb`D. `CuSO_(4)+Fe` |
|
Answer» Correct Answer - d In options (a) and (b) Fe is less reactive than Mg and Zn, so it is not able to replace these hence, no reaction takes place In option (c) Pb is less reactive than Mg. so it is not able to replace it, hence no reaction takes place. In option (d), Fe Is more reactive than Cu so it replaces Cu from `CuSO_(4)`, hence reaction takes place. |
|
| 85. |
Which one of the following Figures correctly describes the process of electrolytic refining? A. B. C. D. |
|
Answer» Correct Answer - C From electrolyte `(CuSO_(4))`, upon passing current, `Cu^(2+)`(aq) ions migrate towards cathode (negative electrode) and are reduced to Cu(s) which is deposited on the electrode. An equivalent amount of copper from avoide (positive electrode) gets oxidised to `Cu^(2+)`(aq) ions which pass into the solution At anode : `Cu^(2+)(aq)+2e^(-) rarrCu(s)`, At anode : `Cu(s) rarr Cu^(2+)(aq) + 2e^(-)` The gas burns with a pop sound when a burning match stick is brought near it. |
|
| 86. |
No chemical reaction takes place when granules of a rusty brown solid A re mixed with the powder of another solid B. however, when the mixture is heated, a reaction takes place between its components. One of the products C is a metal and settles down in the molten state while the other product D floats over it. it was observed that the reaction is highly exothermic. (a) What could the solids A and B be? (b) What are the products C and D most likely to be? (c) Write the chemical equation for the reaction between A and B leading to the formation of C and D. Mention the physical states of all the reactants and products in this equation and indicate tthe heat change which takes place. (d) What is the special name of such a reaction? State one use of such a reaction. (e) Name any two types of chemical reaction under which the above reaction can be classified. |
| Answer» (a) A is iron (III) oxide and B is aluminium (b) C is molten iron metal and D is aluminium oide (c) , (d) Thermite reaction, welding of broken pieces of heavy iron objects like railway tracks, etc. (e) displcement reaction and oxidation-reduction reaction | |
| 87. |
Two ores A and B were taken. On heating, ore A gives `CO_(2)` whereas, ore B gives `SO_(2)`. What steps will you take to convert them into metals ? |
|
Answer» Since ore A gives `CO_(2)` on heating, it must be a carbonate of moderately reactive reative metal like Zn. Hence, it willl be first subjected to calcination (to canvert carbonate ore into metal oxide) followed by reduction ( to convert metal oxide to metal). e.g., `ZnCO_(3)` (calamine). `ZnCO_(3)overset("Heat")toZnO+CO_(2)" (calcination)"` To convert it into metal treat it with carbon. `Zn+C toZn+CO` Since, B gives `SO_(2),` B must be a sulphide ore, e.g., `Cu_(2)S,HgS,` etc. Hence it will be first subjected to roasting (to convert metal oxide to metal). `2ZnS+3O_(2)overset(800^(@)C)to2ZnO+2SO_(2)" (roasting)"` `2Cu_(2)S+3O_(2)overset(Delta)to2Cu_(2)O+2SO_(2)` `2HgS+3O_(2)overset(Delta)to2HgO+2SO_(2)` From these oxide metal is obtained either by using reducing agent like C or by autoreduction. `ZnO+CtoZn+CO` `Cu_(2)S+2Cu_(2)Oto6Cu+SO_(2)` |
|
| 88. |
An ore gives carbon dioxide on treatment with a dilute acid. What steps will you take to convert such a concentrated ore into free metal? |
|
Answer» Whenever a metal carbonate reacts with a dilute acid, carbon dioxie is formed. Since this ore gives carbon dioxide on treatment with a dilute acid, so it is a carbonate ore. A carbonate ore can be converted into free metal in two steps: calcination and reduction: (i). The carbonate ore is strongly heated in the absence of air (calcined) to get the metal oxide: `underset(("carbonate ore"))("Metal carbonate")overset("calcination")to"Metal oxide"+"Carbon dioxide"` (ii) The metal oxide is reduced with carbon to get free metal: Metal oxide+Carbon `overset("Reduction")to` Metal+Carbon monoxide. |
|
| 89. |
A reddish brown coloured metal is used in electrical wires. When powdered and heated strongly in an open china dish, its colour turns black. When hydrogen gas is passed over this black substance, it regains its original colour. Based on the above information, answer the following question. (i) Name the metal and the black coloured substance formed. (ii) Write balanced chemical equations for both the reactions. |
|
Answer» (i) The metal is copper and the black substance is copper (II) oxide or CuO. (ii) `2Cu + O_(2) overset("heat")rarr underset(("Black"))(2Cu(II)O)or 2CuO` `CuO + H_(2) overset ("heat")rarr Cu + H_(2)O` |
|
| 90. |
Name a carbon containing molecule which has two double bonds. |
| Answer» Carbon dioxide, `CO_(2)`. | |
| 91. |
Name two metals which can be used to reduce to metal oxides to metals. |
|
Answer» Metals like Al and Mg can be used to reduce certain oxides of less reactive metals to their oxides. For example, `Cr_(2)O_(3) + 2Aloverset("heat")rarr Al_(2)O_(3) + 2Cr` `Fe_(2)O_(3) + 3Mg overset("heat")rarr 3MgO + 2Fe` |
|
| 92. |
An alkali metal A gives a compound B (molecular mass = 40) on reacting with water. The compound B gives a soluble compound C on treatment with aluminium oxide. Identify A, B and C and give the reactions involved. |
|
Answer» Let, the atomic weight of alkali metal A is x. When it reacts with water it forms a compound B having molecular mass 40. Let, the reaction is `2A+2H_(2)Otounderset((B))(2AOH)+H_(2)uparrow` According to question, molecular mass of compound `B=x+16+1=40` `x=40-17=23` it is the atomic weight of Na (sodium), Therefore, the alkali metal (A) is Na and the reaction is `underset((A))(2Na)+2H_(2)Otounderset((B))(2NaOH)(aq)+H_(2)(g)uparrow` compound B is sodium hydroxide (NaOH) Sodium hydroxide reacts with aluminium oxide `(Al_(2)O_(3))` to give sodium aiuminate `(NaAIO_(2))` Thus, C is sodium aluminate `NaAIO_(2)` The reaction invoved is `Al_(2)O_(3)+underset((B))(2NaOH)tounderset("Sodium aluminate(C)")(2NaAlO_(2))+H_(2)O` |
|
| 93. |
When the powder of a common metal is heated in an open china dish, colour turns black. However, when hydrogen gas is passed over the hot black substance formed, it regains its original colour. Based on this information, answer the following questions : (i) What type of chemical reaction takes place in each of the two given steps ? (ii) Name the metal initially taken in the powder form. Write balanced chemical equations for both these reactions. |
|
Answer» (i) The available information suggests the metal is copper. In open air, its is oxidised to form copper (II) oxide which is black in colour. The reaction is known as oxidation reaction. On passing hydrogen gas over the hot substance, the original colour of the metal is regained. It is an example of reduction reaction. (ii) The balanced chemical equations for the reactions are : `underset(("Metal"))(2Cu(s)) + O_(2)(g) overset("heat")rarr underset(("Black"))underset("Copper (II) oxide")(2CuO(s))` `CuO(s) + H_(2)(g) overset("heat")rarrCu(s) + H_(2)O(g)` |
|
| 94. |
Which gas is produced when dilute hydrochloric acid is added to a reactive metal? Write the chemical reaction when iron reacts with dilute `H_(2)SO_(4).` |
|
Answer» (a) When dilute hydrochloric acid is added ot a reactive metal, then hydrogen gas is produced. (b) When iron reacts with dilute sulphuric acid, the iron (II) sulphate and hydrogen gas are produced. This chemical reaction can be represented by an equation as follows: `underset ("Iron")(Fe(s)) + underset("Sulphuric acid")(H_(2)SO_(4)(aq)to underset("Iron (II) sulphate")(FeSO_(4)(aq))+underset("Hydrogen")(H_(2)(g))` |
|
| 95. |
You can buy solid air-freshnersin shops. Do you think these substanecs are ionic or covalent? Why? |
| Answer» Solid air-freshners are covalent compounds because they are volatile | |
| 96. |
Give one example each of the following (i) A molecule containing a single covalent bond (ii). A molecule containing a double covalent bond (iii). A molecule containing a triple covalent bond. (iv). A compound containing an ionic bond. |
|
Answer» (i) Hydrogen (ii) Oxygen (iii) Nitrogen (iv) sodium chloride. |
|
| 97. |
A covalent molecule having a double bond between its atoms is:A. HydrogenB. OxygenC. WaterD. Ammonia |
|
Answer» Correct Answer - B Correct Answer - b |
|
| 98. |
Fill in the following blanks with suitable words: (a). Magnesium liberates_____gas on reacting with hot boiling water. (b). The white powder formed when magnesium ribbon burns in oxygen is of______ (c). Ordinary aluminium strips are not attacked by water because of the presence of a layer of ______ on the surface of aluminium. (d). A metal having low melting point is_____ but a non-metal having very high melting point is_____ (e). Calcium is a ______reaactive metal than sodium. |
|
Answer» (a)Hydrogen (b) magnesium oxide (c) Aluminium oxide (d).Sodium, diamond (e) less |
|
| 99. |
Explain the nature of the covalent bond using the bond formation in `CH_(3)Cl`. |
|
Answer» `CH_(3)Cl` is methyl chloride (or chloromethane). It is made up of one carbon atom, three hydrogen atoms and one chlorine atom. Carbon atom has 4 outermost electron (or valence electrons), each hydrogen atom has 1 outermost electron, and chlorine atom has 7 valence electrons. carbon atom shares its 4 valence electrons with three hydrogen atoms and one chlorine atom to form `CH_(3)Cl` as shown below. `underset("Hydrogen atom")(3H+)+underset("Carbon atom")(underset(.)overset(.)(*C*)+underset("Chlorine atom")(underset(..)overset(..)(*C: )tounderset("Electron-dot structure of "CH_(3)Cl)(Hunderset(H)overset(H)(underset(. .)overset(. .)( : C : )underset(* *)overset(* *)(Cl: )` or `H-underset(H)underset(|)overset(H)overset(|)(C)-Cl` We can see from the above electron-dot structure of `CH_(3)Cl` that there are four pairs of shared electrons between carbon and other atoms. Eac pair of shared electrons constitues one single covalent bond. So, `CH_(3)Cl` has four single covalent bonds. Please note that each atom in `CH_(3)Cl` has a noble gas electron arrangement (of 2 or 8 electrons in the outermost shell). |
|
| 100. |
Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same ? (i) Good thermal conductivity (ii) Good electrical conductivity (iii) Ductility (iv) High melting pointA. (i) and (ii)B. (i) and (iii)C. (ii) and (iii)D. (i) and (iv) |
|
Answer» Correct Answer - D In order that a metal may be used for making cooking utensils, it must be good conductor of heat and also must have high melting point so that it may withstand high temperature. |
|