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.
| 7201. |
Butanone is a four-carbon compound with the functional group |
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Answer» CARBOXYLIC acid |
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| 7202. |
Butanal is organic compound with the functional group |
| Answer» Answer :C | |
| 7203. |
Burning substances (fuels) burn with or without a flame. |
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Answer» Solution :When the gaseous substances are heated, a LUMINOUS FLAME is seen and they start to glow. Some liquid and solid fuels burn with a flame because on heating, their atoms easily get converted into vapours, and burn with a luminous flame starting with glow. When volatile substances present in this TYPE of fuel vapourises, then the fuel just glows red and GIVES out heat without flame. |
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| 7204. |
Burning of methane to give carbon dioxide and water is an _________ reaction. |
| Answer» SOLUTION :EXOTHERMIC | |
| 7205. |
Burning of magnesium ribbon in air is both a combination reaction and an oxidation reaction. |
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Answer» |
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| 7206. |
Burning of coal and formation of water is ……… type of reaction. |
| Answer» SOLUTION :COMBINATION | |
| 7208. |
Buring of a magnesium ribbon in air takes place with |
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Answer» a GREEN FLAME |
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| 7209. |
Bunty is a ten year old by who was playing in the park with other friends. Suddenly a wasp came flying and stung him on the face. Bunty felt a lot of pain and came running home . Just then, Bunty's younger sister Arti, who is just five five years old was stung by an ant an on the arm causing a lot of burning pain. She also came running home Bunty's elder sister Reema who is a student of class X was at home at that time. Reema immediately took vinegar bottle from the kitchen shelf and rubbed some vinegar on the stung area of skin on Bunty's face. This gave Bunty some relief. Reema than took baking soda container from the kitchen made a solution of baking soda in water, and rubbed this baking soda solution on the stung area of Arti's arm. She also got relief from pain. (a) What type of liquid was injected by wasp's sting into Bunty's skin? (b) Why did rubing vinegar on the stung area of skin reduce Bunty'spain? (c) Which chemical is injected by an ant's ting into Arti's skin? (d) Why did rubbing baking soda solution on stung area of skin reduce Arti's pain? (e) Name a plant whose stinging leaf hair inject the same chemical into the skin of a person (who touches it) as the anty's sting. (f) What type of chemical reaction takes place: (i) When vinegar is rubbed on Bunty's skin having wasp sting? (ii) When baking soda solution is rubbed on Arti's arm having ant's sting? (g) What values are displayed by Reema in this whole episode? |
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Answer» Solution :(a) Alkaline liquid (or basic liquid). (b) Vinegar is an acidic substance. Being an acidic substance, vinegar neutralise the alkaline liquid (or basic liquid) injected by was sting and cancels its effect. (c) Methanoic acid. (d) Baking soda is a base (or basic substance). Being a basic substance, baking soda neutralises the methanoic acid injected by an ant's sting and cancels its effect. (e) NETTLE plant (F) (i) Neutralisation reaction (II) Neutralisation reaction (g) The VALUES displayed by Reema in this EPISODE are (i) Awareness (or knowledge) that a was sting injects an alkaline liquid whereas an ant's sting injects an acidic liquid into skin (ii) Understanding of neutralisation reactions of acids and bases, and (iii) Desire to mitigate the suffering of others. |
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| 7210. |
"Building crescent shaped earthen embankment in level terrain is better than the construction of large dams across the river to store water". Analyse this statement with their effects. |
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Answer» Solution :• ln terrain, the crescent shaped embankments are used as water harvesting structures. They are advantageous as : • The water in them do not evaporate easily. • They help in recharging wells and providing moistwe for vegetation over a long STRETCH of land. • They do not allow mosquitoes to breed. • Such embankments are also protected from animals and HUMAN waste. • Harnessing of water by building dams has its own social, economic and environmental PROBLEMS. • Soda! : As many displace large number of peasants and tnbals without adequate compensation and rehabilitation. • Economic : Huge amount of public money is used. • Environmental: They lead to deforestation. THUS, the statement is justified |
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| 7211. |
Buckminsterfullerene is an allotropic form of |
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Answer» phosphorus |
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| 7212. |
Buckminster fullerene is an example of _____ of carbon |
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Answer» An isomer |
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| 7213. |
Buckminster fullerene is an allotropic form of |
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Answer» nitrogen |
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| 7215. |
Brushing teeth twice a day helps to have healthy habit. Why is it a good habit ? |
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Answer» Solution :Tooth decay starts when the pH of the mouth is lower than 5.5. Tooth enamel, made up o calcium phosphate is the hardest substance in the body. It does not dissolve in WATER, but is corroded when the pH in the mouth is below 5.5. Bacteria present in the mouth DEGRADES sugar and food particles REMAINING in the mouth and produce acids. This reduces the pH in the mouth. The best way to PREVENT this is to CLEAN the mouth each time after eating food. Using toothpastes, which are generally basic, for cleaning the teeth can neutralise the excess acid and prevent tooth decay. |
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| 7216. |
"Brownian Movement" name was given after which scientist |
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Answer» JOSEPH Brown |
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| 7217. |
Bromine solution is decolourised by ___ (ethene only/ethyne only/both entences ethene and ethyne) |
| Answer» SOLUTION :both ETHENE and ETHYNE | |
| 7218. |
Briefly write any four characterisitcs of group in the periodic table . |
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Answer» Solution : (i) The element present in a group have the same VALENCY . (ii) The element present in a group identical CHEMCIAL PROPERTIES . (iii) the phyical properties of the elements in the group very GRADUALLY . (iv) The atomic radii of the element present in a group INCREASES downwards. |
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| 7219. |
Brass is an example of a ____ |
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Answer» HOMOGENEOUS compound |
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| 7220. |
Brass is an alloy of copper and zinc. A sample of brass weighing 5.793 g, when treated with excess of dil. H_(2)SO_(4) gave 336mL of hydrogen gas at136.5 K and 785 mm pressure. If thehydrogen gas is collected over water andpressure of water vapour under thegiven conditions is 25 mm, find out thepercentage weight of copper in the alloy. |
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Answer» Solution :AMONG Cu and Zn, only Zn displaces `H_(2)" from "H_(2)SO_(4)` `Zn+H_(2)SO_(4) to ZnSO_(4) + H_(2)` Pressure = 785 - 25 = 760 mm TEMPERATURE = 136.5 K, volume = 336mL `(P_(1)V_(1))/T_(1) = (P_(2)V_(2))/T_(2)` `(760 xx 336)/(136.5) = (760 xx V_(2))/(273)` ` V_(2) = 672` mL `(V_(2))` Vol. of `H_(2)` liberated at STP = 672 mL Weight of zincrequired= `(65.5 xx 672)/(22400) = 1.965` g Weight of copper in brass = `5.793 - 1.965 = 3.828` g % of Cu in the alloy = `(3.828)/(5.793) xx 100 = 66%` |
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| 7222. |
Boyle's lew says that pressure and volume are inversely proportional to each other. However, when a balloon is blown,both volume and pressure increasecontinuously. Justify |
| Answer» Solution :When a balloon is blown continuously, more and more air is forced into the balloon that increases the volume as WELL as the numberof collisions of collisions of air molecules on the WALLS of theballoon, that is pressure. Boyle's law is applicable for a GIVEN mass of a gas.Hence, it is not valid in the above CASE. | |
| 7223. |
Both soap and detergent are some type of salts. What is the difference between them? Describe in brief the cleansing action of soap. Why do soaps not form lather in headwater? List two problems that arise due to the use of detergents instead of soaps . |
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Answer» Solution :Soaps are sodium or potassium slats of long-chain carboxylic acids. Detergents are generally ammonium or sulphonate SALTS of long chaincarboxylic acids. Soaps do not form lather in hard water because hard water contains calcium and MAGNESIUM salts. SOAP MOLECULES react with calcium and magnesium salts to form an isoluble precipitate called scum. Two problems which arise because of the use ofdetergents are: (i) Detergents are non-biodegradable, hence, detergents accumulate in the environment and cause problems. (ii) Certain phosphate ADDITIVES are added to detergents which form a thick green scum over the river water and harm the animal life in the river. |
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| 7224. |
Both soap and detergent are same type of salts. What is the difference between them ? Describe in brief the cleansing action of soap. Why do soaps not form lather in hard water? |
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Answer» Solution :Soaps are sodium or potassium salts of long chain carboxylic acids. DETERGENTS and antingnium or sulphonate salts. Cleaning action of soap : One part of soap molecule ionic/hydrophilic and dissolves in WATER. The other part is non-ionic/carbon chain/hydrophobic part which dissolves in oil. Thus soap MOLECULES arrange themselves in the form of a micelle/diagram of a micelle. On RINSING with water soap is washed on the oily dirt particles with it Soap does not form lather in hard water because of the reaction of soap with Ca and Mgions present in hard water which forms insoluble precipitate scum. |
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| 7226. |
Both helium and beryllium have ns^(2) valence electronic configuration. However, beryllium forms compounds and helium cannot form compounds. Explain. |
| Answer» Solution :Both HELIUM and beryllium have `ns^(2)` valence electronic configuration. Beryllium has an electron PAIR in 2S orbital and all three 2p orbitals are vacant. The paired electron of 2s orbital can be excited to 2p orbital thereby giving a covalency of 2. Helium has an electron pair in '1s' orbital and there is no SCOPE for excitation of electrons in first SHELL. Hence, Helium can not form any compounds. | |
| 7227. |
Both H_(2) and CO_(2) gases are... |
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Answer» HEAVIER than AIR. |
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| 7228. |
Both ethyl alcohol (C_(2)H_(5)OH) and glucose (C_(6)H_(12)O_(6)) contain hydrogen but do not give the characteristics tests of acids. Assing reason. |
| Answer» | |
| 7229. |
Boron, Silicon, Potassium , Antimony |
| Answer» SOLUTION :POTASSIUM: It is a METAL while OTHERS are METALLOIDS. | |
| 7230. |
Boron, Silicon, Neon , Polonium |
| Answer» SOLUTION :NEON : It is an inert GAS, whereas all others are METALLOIDS. | |
| 7231. |
Boron naturally occurs as a mixture of boron - 10 ("5 protons "+" 5 neutrons") and boron11 ("5 protons "+" 6 neutrons") isotopes. The percentage abundance of B-10 is 20 and that of B-11 is 80. Then, the atomic mass of boron in calculated as follows : |
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Answer» SOLUTION :`"Atomic mass of BORON "=(10xx(20)/(100))+(11xx(80)/(100))` `=(10xx0.20)+(11xx0.80)` `=2+8.8="10.8 amu"` |
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| 7232. |
Boron is the first element of group 13. Name the second element of this group. |
| Answer» SOLUTION : ALUMINIUM (AL) | |
| 7233. |
Boron - 10 and Boron - 11 are called …………. . |
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Answer» ISOTOPES |
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| 7234. |
Bondformation______ energyduringa chemicalreaction . |
| Answer» SOLUTION :releasesbondformation | |
| 7235. |
Bond breaking releaser energy whereas bond formation absorbs energy |
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Answer» Solution :FALSE Correct statement:BOND breaking absorbs energy whereas bond FORMATION RELEASES energy. |
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| 7236. |
Bondbreaking_________ energyduringa chemicalreaction . |
| Answer» SOLUTION :absorbsbondbreaking | |
| 7238. |
Bohar's model introduced the concept of quantisationof "____________" |
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Answer» |
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| 7239. |
Blue crystals of copper sulphate on heating in a dry test tube become colourless. Why ? |
| Answer» Solution :The blue COLOUR of COPPER sulphate is due to five water molecules attached with it. On heating, it LOSES water molecules, and become COLOURLESS. [It is converted into anhydrous white `CuSO_(4)`]. | |
| 7240. |
Blister copper is purified by ____________ |
| Answer» SOLUTION :electrolyticrefining | |
| 7241. |
Bleaching powder when treated with dil. HCl gives : |
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Answer» `CO_2 ` GAS |
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| 7245. |
Bishnoi Movement ' was fought under the leadership of |
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Answer» Medha patekar |
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| 7246. |
"Biogas plant is a boon to farmers. Why? |
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Answer» Solution :Biogas is obtained by the decomposition of animal and PLANT wastes LIKE animal dung etc., with the help of microorganisms in the presence of water. (1) It produces clean FUEL . (2) The slurry can be used to generate ELECTRICITY. (3) The remains of biogas plant can be used by farmer as manure. |
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| 7248. |
Biodegradabledetergentsare made of ______ (branched / straight ) chain hydrocarbons . |
| Answer» SOLUTION :STRAIGHT | |
| 7249. |
Bharat stage II is related to |
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Answer» SOIL pollution |
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