InterviewSolution
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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.
| 601. |
The reduction of metallic oxide in presence of carbon or carbon monoxide ib blast furnace is called _____________. |
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Answer» |
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| 602. |
The sulphide ores which involve roasting as one of the steps of extraction are concentrated by certain method. Identify the main principle involved. |
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Answer» adsorption of ore PARTICLES to pine OIL |
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| 603. |
Which of the following process/processes release heat ?(i) condensation(ii) vaporisation(iii) freezing(iv) melting |
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Answer» only (i) |
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| 605. |
Why are shaving creams and shampoos softer than soap? |
| Answer» SOLUTION :Soaps are prepared by subjecting oils or FATS to hydro- lysis with sodium hydroxide. That means,soaps are sodium SALTS of higher fatty ACIDS. Shampoos and shaving creams are prepared by subjecting oils or fats to hydrolysis with potassium. hydroxide. That means they are potassium salts of higher fatty acid Potassium salts are more Soluble than sodium salts. Hence shampoos and shaving creams are softer than soaps. | |
| 606. |
What do you mean by latent heat of fusion? |
| Answer» Solution :The heat REQUIRED to CHANGE 1 Kg of a solid substance into liquid state at the melting POINT of the substance. | |
| 607. |
Which elements are called rare earths? |
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Answer» Lanthanoids |
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| 608. |
Write the main postulates of Bohr's model of an atom. |
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Answer» Solution : The main POSTULATES of Bohr.s model of an atom as FOLLOWS: (1) Only speclal orbits known as discrete orbits of electrons, are ALLOWED INSIDE the atom. (2) While revolving in discrete orbits the electrons do not radiate energy. |
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| 609. |
Two miscible liquids A and B are present in a solution. The boiling point of A is 60^(@)C while that of B is 98^(@)C. Suggest a method to separate the components of the mixture. Why are they separated by this process ? |
| Answer» Solution :The method of distillation is used to SEPARATE the given miscible liquids A and B, because the difference in their BOILING POINTS is more than `25^(@)C`. | |
| 610. |
A sample of an element X contains two isotopes ._(8)^(16)X and ._(8)^(18)X. If the average atomic mass of this sample of the element be 16.2 u, calculate the percentage of the two isotopes in this sample. |
| Answer» SOLUTION :`""_(8)^(16)A=90%,""_(8)^(18)A=10%` | |
| 611. |
What is a dispersed phase in a colloidal solution? |
| Answer» SOLUTION :The particles of COLLOID substance CONSTITUTE the dispersed phase. | |
| 612. |
You have just won a medal made of 22-carat gold. Have you just procured a part substance or impure substance? |
| Answer» Solution :I have procureds an IMPURE SUBSTANCE. It is MADE of 22 parts of pure gold and 2 parts of copper or silver. | |
| 613. |
Which of the following is odd one out ? Bromine, Carbon, Nitrogen, Steam, Sulphur. |
| Answer» SOLUTION :STEAM. It is a COMPOUND. The OTHERS are ELEMENTS. | |
| 614. |
When heat is constantly supplied by a gas burner with small flame to melt ice, then the temperature of ice during melting : |
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Answer» INCREASE very slowly |
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| 615. |
What is meant by groups and periods in the periodic table? |
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| 616. |
The solid, inorganic compounds found in the earth's crust are called minerals. |
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| 617. |
Write the chemical formulae of the following: (a) Magnesium chloride (b) Calcium oxide (c) Copper nitrate (d) Aluminium chloride (e) Calcium carbonate |
Answer» SOLUTION :
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| 618. |
Tincture of iodine has antiseptic properties. This solution is made by dissolving _____ . |
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Answer» IODINE in POTASSIUM iodide |
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| 619. |
Write the stepsyou woulduse to making tea.Use the wordssolution , Solvents ,Solute, dissolve ,soluble , insoluble , filtrateand residue ? |
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Answer» Solution :i. Tea can be prepared by following steps : Take 100 ml of water as solvent and boil it few minutes. ii. Now add one tea spoon SUGAR, one tea spoon tea LEAVES and 50 ml of milk. Here sugar, tea leaves and milk are solute. iii. Now boil it again for few minutes so that sugar will dissolve in solution as sugar is soluble in water iv. Now filter the solution, collect the filterate in a cup. The insoluble tea leaves will be LEFT BEHIND as RESIDUE. |
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| 620. |
Which of the following conditions will accelerate the rate of evaporation of a liquid ? |
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Answer» DECREASE in TEMPERATURE |
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| 621. |
Write the methods of separation for the following: |
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Answer» Solution :(a) Separation of insoluble solids from liquids FILTRATION and Decantation (b) The separation of fine and tiny particles of solid which do not SETTLE at the bottom. Centrifugation (C ) Separation of soluble solids from liquids Evaporation and crystallization (d) Separation of miscible liquids which do not differ much in their boiling points Fractional distillation. (e) Separation of TWO immiscible liquids Separating funnel (f) Separation of different fractions of petroleum Fractional distillation with fractionating column (g) Separation of mixture containing VOLATILE and non-volatile solids. Sublimation. |
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| 622. |
Water is the best and universal solvent. |
| Answer» SOLUTION :(1) Water at normal temperature is in liquid state. (2) It is AVAILABLE easily EVERYWHERE. (3) Various types of substances DISSOLVE easily in water to form SOLUTIONS. Thus, water is an important solvent to form variety of solutions. Thus, water is the best and universal solvent. | |
| 623. |
What is observed on transferring a liquid from one vessel to another? |
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Answer» it CHANGES its SHAPE and vlume. |
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| 625. |
When a carbon fuel burns in less aerated room, it is dangerous to stay there. Why? |
| Answer» SOLUTION :When carbon fuel burns in less AERATED ROOM, carbon monoxide is formed. When people are exposed to CO, it ENTERS into human body through breathing and affects the function of haemoglobin. CO displaces oxygen from haemoglobin thereby stops its function (supply of oxygen to the PARTS of body) leading to death. | |
| 626. |
Whatare pure substances? Give examples. |
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Answer» SOLUTION :Pure substances contain only one kind of particles. Eg. 1. Element (Sodium, Bromine, and HYDROGEN) 2. Compound (Sodium chloride, water, CARBON DIOXIDE) |
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| 627. |
Why are the metals sodium and postassium not extracted by the electrolysis of their respective salt solutions ? |
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Answer» SOLUTION :(i) electropositivity. (ii) ions formed during electrolysis of AQUEOUS SALT solution (iii) Fate of ions after formation (iv) discharge of ions at the RESPECTIVE electrodes |
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| 628. |
What is the atomicity of all the inactive (noble) gases? |
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Answer» ONE |
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| 629. |
What is the principle used in a pressure cooker ? |
| Answer» Solution :The pressure in the enclosed volume above the liquid REACHES much greater values than atmospheric pressure, THUS the temperature of BOILING water within the cooker is greater than the NORMAL boiling temperature. Hence, things cook much FASTER. | |
| 630. |
What is the physical state of water at (a) 25^(@)C, (b) 0^(@)C, (c) 100^(@)C. |
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Answer» SOLUTION :(a) `25^(@)C` the physical STATE of water is liquid (b) `0^(@)C`, the physical state of water is either a solid or a liquid. (c) `100^(@)C`, the physical state of water can be either a liquid or a GAS. |
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| 631. |
When equal number of moles of CO_(2), SO_(3) and nitrogen gases are passed through water under pressure and then heated, which gas is evolved in maximum percentage ? Justify. |
| Answer» Solution :As solubility of NITROGEN is very less in WATER, it is expelled in MAXIMUM PERCENTAGE. `CO_(2)` and `SO_(3)` are soluble in water. Hence, they will be expelled in LESSER percentage. | |
| 632. |
What is a resin code? What is the need to display them on plastic articles? |
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Answer» Solution :The resin code is a set of symbols appearing on plastic products that is helpful in the identification of the TYPE of polymer used to MAKE that product. Platic needs to be recycled or DISPOSED of safely. Each plastic is composed of a different polymer or set of MOLECULES. Differnet molecules do not mix when PLASTICS are recycled. For this reason plastics need to be seggregated before recyling. These resin codes help in easy seggregation of plastic products to be recycled. |
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| 633. |
What is the physical state of water at (a) 25^(@)C (b) 100^(@)C |
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Answer» SOLUTION :(a) Gaseous state (As boiling temperature of the water is `100^(@)C`) (b) Since water boils at this temperature thus it can EXIST in both liquid and gaseous form. At this temperature, after GETTING the heat EQUAL to the latent heat of vapourisation water starts changing from liquid state to gaseous state. |
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| 634. |
What is mass number ? |
| Answer» SOLUTION :The mass number of an atom is the sum of the TOTAL number of PROTONS and neutrons PRESENT in the nucleus of an atom. It is denoted by symbol .A.. e-g. the mass number of oxygen is 16. | |
| 635. |
Trees act as soil binders. |
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| 636. |
What would happen, if all the oxygen present in the enviroment is converted to ozone ? |
| Answer» Solution :All organisms living on the earth will DIE of SUFFOCATION DUE to lack of oxygen. | |
| 637. |
Which of the following statements about the formation of a compound is ( are ) correct ? |
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Answer» A compound contains only one KIND of element . |
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| 638. |
What is valency? |
| Answer» SOLUTION :The COMBINING capacity of an element is KNOWN as its VALENCY. | |
| 639. |
What is Forensic chemistry related to ? |
| Answer» Solution :FORENSIC chemistry aspplies scientific PRINCIPLES, TECHNIQUES, and methods to the investigation of CRIME. | |
| 640. |
Two acids 'A' and 'B'are given. Acid A gives one hydrogen lon per molecule of the acid in solution. Acld B gives two hydrogen ions per molecule of the acid in solution. (i)Find out acid A and acid B. (ii) Which acid is called the King of Chemicals? |
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Answer» SOLUTION :Acid A is HCl and Acid B is `H_2SO_4` (ii) SULPHURIC acid is CALLED the KING of Chemicals. |
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| 641. |
What do you think would be thee observation if the a-particle scattering experiment is carried out using a foil of a metal other than gold? |
| Answer» SOLUTION :If `ALPHA`-particle scattering experiment iscarried out using a foil of METAL other than gold. there WOULD be no CHARGE in observation as all atom have the same structure. | |
| 642. |
What conclusion were made from the observations of Gold foil experiment? |
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Answer» Solution :In Rutherford.s Alpha RAY scattering experiment, the following conclusions were made from the OBSERVATIONS. (a) ATOM has a very small nucleus at the centre . (b) There is a large empty space around the nucleus . ( c) The entiremass of an atomic is concentrated in a very small positively charged region, which is called Nucleus . (d) The electrons are distributed in the VACANT space around the nucleus. (e) The electrons move in CIRCULAR paths around the nucleus. |
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| 643. |
Which of the following is a (are ) chemical change(s) ? |
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Answer» DRAWING a wire of copper |
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| 644. |
Write some examples of theCompounds? |
| Answer» Solution :CALCIUM CARBONATE , Methane, CARBON DIOXIDE, soap | |
| 645. |
What are the uses of dry ice? |
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Answer» SOLUTION :(a) ACT as cooling agent (b) Industrial refrigeration (C ) Transportinng frozen food. (d) It does leave any liquid behind, as it directly CHANGES into gas. |
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| 646. |
The term nucleons refer to ………….. . |
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Answer» PROTONS and electrons |
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| 648. |
What is adsorption? Give example. |
| Answer» Solution :Adsorptionn is the process in which particles of a substances, ADHERE to a surface of ANOTHER SUBSTANCE. Eg. CHARCOAL adsorbs gases on its surface. | |
| 649. |
There is very negliglble contribution of electrons in deciding the atomic mass. |
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Answer» |
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| 650. |
Write the formula of the Chromium sulphate |
| Answer» SOLUTION :CHROMIUM SULPHATE = `Cr_2 (SO_4)_3` | |