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.
| 351. |
The symbol for the metal used in thermometer is …..... . |
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Answer» Ag |
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| 352. |
What do you observe : Sulphur dioxide is passed through acidified K_(2)Cr_(2)O_(7) solution. |
| Answer» SOLUTION :ORANGE solution TURNS GREEN. | |
| 353. |
What is a neutron ? |
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Answer» Solution :A neutron is an ELEMENTARY particle having mass approximately equal to that of a PROTON. [ Mass of proton: 1.672614 `XX 10^(-27)` kg mass of neutron : 1.674928 `xx 10^(-27)` kg ] |
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| 354. |
Which among the following is not a homogeneous mixture ? |
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Answer» solder |
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| 355. |
What is the valency of the element with atomic number 36 and mass number 84 ? |
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Answer» 2 |
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| 356. |
What was the need to classify element? |
| Answer» | |
| 357. |
Which of the noble gas does not have octet arrangement in the outermost shell? |
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Answer» |
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| 358. |
When you pour the liquid from one container into another does it flow easily? |
| Answer» SOLUTION :The liquid FLOWS easily, if transferred from ONE CONTAINER to the other. | |
| 359. |
What change in temperature occurs, while theentire ice is melting? |
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Answer» DECREASES slowly |
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| 360. |
The representation of Bohr model of elements with atomic number 3 to 9 in the second period of the periodic table. Is there are in the number of shells with the increase in atomic number? |
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Answer» |
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| 361. |
Which of the following expressions can be used to describe the rate of reaction for the equation, 2X + Y to X_(2)Y ? |
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Answer» `(-Delta[X])/(Delta t)` |
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| 362. |
Which of the following is the correct order of convertinv 25^(@)C, 38^(@)C and 66^(@)C into Kelvin scale? |
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Answer» 298 J, 300 K, 338 K |
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| 363. |
Three elements X,Y,and Z form a Doberiener triad The ratio of the aotmic weight of x to theat of Z is 160 find the atomic weight of X,Y and Z |
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Answer» Solution :Let the atomic WEIGHTS of X,Y and Z be `Z_(x),Z_(y)` and`Z_(z)` respectively `therefore (Z_(x))/(Z_(z))=(7)/(25)rarrZ_(x)=(7)/(25).Z_(z)rarr(1)` Given htat `Z_(x)+Z(z)`=160 `therefore (7)/(25).Z_(z)=160rarrZ_(z)=125` fromequation (1) `Z_(x)=(7)/(25).125=35` atomic weight of y is `Z_(y)=(35+125)/(2)=80` `[therefore` X,Y and Z form DOBEREINER TRAID] |
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| 364. |
Which of the following chemical formulae is(are) correct ? |
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Answer» `NaPO_(4)` |
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| 366. |
To which physical state of matter, do the following statements apply ? (a) incompressible, no fixed shape (b) incompressible, high melting point (c ) compressible, no definite volume (d) incompressible, highly fluid. |
| Answer» SOLUTION :(a) Liquid STATE (b) Solid state (C ) GASEOUS state (d) Liquid state. | |
| 367. |
What are the limitations of Rutherford's model? |
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Answer» Solution :The limitations of Rutherford.s model of the at atom are ● It FAILED to EXPLAIN the STABILITY of an atom ● It doesn.t explain the spectrum of hydrogen and other atoms. |
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| 368. |
Which of the following is most suitable for summer. |
| Answer» ANSWER :A | |
| 370. |
What is an atom ? |
| Answer» SOLUTION :an ATOM is the smallest PARTICLE of an element which takes part in chemical REACTIONS. | |
| 371. |
Which of the following statement is (are) incorrect about an atom? |
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Answer» An atom can EXIST independently . |
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| 372. |
Which among the following is the false statement ? |
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Answer» WATER boils below `100^(@)` C on mountain peaks. |
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| 373. |
Which of the following statements is (are) incorrect ? |
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Answer» Atomic NUMBER = number of NEUTRONS + number of electrons |
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| 374. |
What is an octet? Why do atoms complete their octet ? |
| Answer» Solution :When the outermost shell of an atom (i.e., L , M or N ) is COMPLETELY filled with 8 electrons, it is sald to be an octet. Atoms TRY to complete their octet to ACHIEVE stability. | |
| 376. |
What happens when blue litmus paper is dipped in water in which a piece of calcium metal is dropped ? |
| Answer» Solution :Blue litmus PAPER remains blue as calcium reacts with WATER to form `CA(OH)_(2)` which is BASIC in nature. | |
| 377. |
Vibha is a student of 9th standard. Vibha's family has an LPG connection in the kitchen. When Vibha's mother, Mrs. Chopra, was preparing breakfast for the family, the cooking gas cylinder got empty. Mrs. Chopra keeps a spare gas cylinder. So, she removed the empty gas cylinder and connected the filled gas cylinder tp the cooking gas stove. Mrs. Chopra then lighted the gas stove adn started preparing breakfast again. Just then Vibha came running into the kitchen and told her mother that she could smell the leaking cooking gas from the new LPG cylinder even from a distance. Vibha closed the gas supply from the leaking cylinder by turning off the regulator knob quickly. She also asked her mother not to use this leaking gas cylinder till the leakage is set right. She also opened the window of kitchen to let the leaked gas cylinder. The gas mechanic of the distributor on telephone and complained about theleaking gas cylinder, The gas mechanic of the distributor came to Vibha's house within half an hour. When he checked the gas cylinder, he found that the rubber washer of the cylinder had a cut in it through which the gas was leaking. The gas mechanic changed the defective rubber washer and then checked for the leakage again. There was no gas leakage rectification service is provided freeof charge by the LPG distributor. Mrs. Chopra was happy that Vibha had saved their lives as well as money. (a) (i) What substance is added to the LPG cylinder by the filling company to help in detecting gas leakage from the cylinder ? (ii) Which property of the above substance is made use of in detecting the leaking gas from LPG cylinder ? (b) Name the physical process which helps in bringing leaking LPG containing the above substance to us even from a distance (c) Define the above physical process (d) How is the leaking cooking gas from LPG cylinder detected ? (e) What would have happened if Mrs. Chopra had continued to use the leaking gas cylinder ? (f) What values are displayed by Vibha in this episode ? |
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Answer» SOLUTION :(a) (i) Ethyl mercaptan (ii) Strong smell of ethyl mercaptan (b) Diffusion (in gases) (c) The spreading out and mixing of a gas with another gas due to the motion of their PARTICLES is called diffusion in gases (d) The leaking cooking gas containing the strong smelling substance ethyl mercaptan spreads and mixes with the surrounding air by the process of diffusion. When the air containing ethyl mercaptan reaches our nose, we can smell it and come to know of the gas leakage (e) LPG is a highly inflammable gas (which catches fire very easily). If Mrs. Chopra had continued to use the leaking LPG cylinder, then a lot of LPG would have collected in the kitch after some time. This collected LPG could ignite on coming in contact with gas stove flame causing a bif fire in the KITCHEN. even the LPG cylinder could catch fire and BURST causing a big explostion. This could lead to the loss of lifeand property (f) The various VALUES displayed by Vibha in this episode are (i) Good smelling powder (so as to smell leaking cooking gas even from a distance) (ii) Knowledge of the risksof using a leaking LPG cylinder (iii) Responsible citizen (in calling LPG distributor to rectify gas leakage), and (iv) Destire to protect her family and property (from any LPG related accident). |
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| 378. |
Which of the following figures illustrates the sublimation process? |
| Answer» Answer :A::B::C::D | |
| 379. |
What produces more severe burns, boiling water or steam? |
| Answer» Solution :When water changes into steam at its boiling point, it absorbs latent heat of vaporisation (which is `22.5 xx 10^(5)` joules PER kilogram). This MEANS that steam at `100^(@)C` contains much more heat (in the form of latent heat) than boiling water at the same temperature of `100^(@)C`. So, when steam FALLS on our skin and condenses to form water, it gives out much more heat than boiling water, it causes more severe burns. | |
| 380. |
What are elements ? |
| Answer» SOLUTION :Elements are SUBSTANCE that cannot be chemically broken down into SIMPLER substances. So an element is MADE up of only one kind of atoms. | |
| 381. |
What is the mass ingrams of a single atom of chlorine ? (Atomic mass of chlorine = 35.5) |
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Answer» SOLUTION :`6.022 xx 10^(23)` atoms of CL= GRAM atomic MASS of Cl = 35. 5 g `therefore` mass of 1 atom of Cl = `(35.5 g)/(6.022 xx 10^(23)) = 5.9 xx 10^(-23) g`. |
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| 383. |
To make a saturated solution of 36g of sodium chloridein 100g of water at 293K find its concentrationat this temperature. |
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Answer» SOLUTION :Mass of solute (sodium chloride) = 36g (GIVEN) Mass of solvent (water) = 100G (Given) Then, mass of solution = Mass of Solute + Mass of solvent. = (36 + 100)g = 136g `= ("Mass of solute")/("Mass of solvent") XX 100%` `= (36)/(136) xx 100%` = 26.47% |
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| 384. |
Which radi oisotope is used in carbon dating? |
| Answer» | |
| 385. |
What do you observe immediately after adding a drop of honey? |
| Answer» Solution :HONEY TAKES longer time to spread in WATER. | |
| 386. |
The valency of two elements are given below. Al-3,O-2 The chemical formula of aluminium oxide is _____ |
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Answer» ALO |
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| 388. |
The valency of nitrogen in ammonia (NH_(3)) is |
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Answer» 2 |
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| 389. |
What is meant by the term chemical formula ? |
| Answer» SOLUTION :The CHEMICAL formula of a compound is a symbolic representation of its COMPOSITION. | |
| 390. |
What is a solute ? |
| Answer» Solution :The COMPONENT (USUALLY present in SMALL AMOUNT) that is dissolved in a solution is KNOWN as a solute. | |
| 391. |
Wrought iron is more malleable than cast iron. Give reasons. |
| Answer» Solution :WROUGHT iron is the purest form of iron. Its carbon CONTENT is LEAST. HENCE, it is highly malleable whereas cast iron has RELATIVELY more carbon content along with other impurites. Hence , it is less malleable. | |
| 392. |
What is the difference between a proton and a neutron ? |
| Answer» SOLUTION :PROTON carries a UNIT positive CHARGE. NEUTRON carrles no charge. | |
| 393. |
The temperature time graph given below shows the heating curve for pure wax. From the graph answer the following questions: a. What is the physical state of wax at the points A,B,C,D? b.What is the melting point of wax? c. What is its boiling point? d. Which portions of the graph indicate that change of state is taking place? e. Name the terms used for heat absorbed during the change of slates involved in above process. |
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Answer» SOLUTION :a.A: solid , B: Solid as well as LIQUID, C: Liquid, D. liquid as well as vapour. b.The melting pont of wax is `15^(@)C` c.The BOILING point of wax is `110^(@)C` d. `A_(1)B_(1)` and `D_(1)D_(2)` show the change of states taking place. e.`A_(1)B_(1):Latent heat of fusion. `D_(1)D_(2):` Latent heat of vaporisation. |
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| 394. |
There are 4 electrons in the M shell of an element. Write the electron configuration of the element. |
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Answer» |
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| 395. |
Which of the followingis a chemical change ? |
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Answer» mixitng of IRON FILINGS and SAND |
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| 396. |
The valencies of magnesium and aluminium are ......... Respectively. (2 and 3, 1 and 3,3 and 2 ) |
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Answer» |
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| 397. |
What type of reaction is involved in the usage of AgBr in photography ? The positive print developed is dipped in AuCl_3 solution at the end to impart beautiful appearance to the photograph. Explain the reactioninvolved in this. Justfy. |
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Answer» SOLUTION :(i) EFFECT of light on AgBr (II) COMPARISION of reactivity of AG and Au |
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| 398. |
Which of the following is liquid - liquid solution ? |
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Answer» FACE cream |
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