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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.
| 4251. |
Name a halogen, a metal and a group13 element which are liquid at30^@C. |
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Answer» <BR> ANSWER :Br, HG, GA |
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| 4252. |
Name a compound which hardens on wetting with water. |
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Answer» CALCIUM SULPHATE decahydrate |
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| 4253. |
Name a compound of copper in which copper shows the valency of 1. |
| Answer» SOLUTION :CUPROUS chloride ` (Cu_(2)Cl_(2))` | |
| 4254. |
Naman saw his friend riding a cycle which was completely rusted at the edge of the pedal. He advised his friend to weld it and apply a coating of oil paint over it. What value of Naman is seen in the above act? |
| Answer» SOLUTION :NAMAN SHOWED the value of AWARENESS, concern and HELPFUL nature. | |
| 4255. |
Naman saw his friend riding a cycle which was completely rusted at the edge of the pedal. He advised his friend to weld it and apply a coating of oil paint over it. Give two remedies to avoid rusting. |
| Answer» Solution : Remedies to AVOID rusting are: (i) APPLY PAINT on the SURFACE of iron. (ii) Apply GREASE or oil coating on iron. | |
| 4256. |
Naman saw his friend riding a cycle which was completely rusted at the edge of the pedal. He advised his friend to weld it and apply a coating of oil paint over it. Why do iron rust? |
| Answer» Solution : Iron, when exposed to air and moisture, undergoes chemical change to FORM iron OXIDE which is reddish BROWN POWDER called rust. | |
| 4257. |
NaHCO_(3) represents the formula of which one of the following? |
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Answer» SODIUM carbonate |
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| 4258. |
NaOH is ? |
| Answer» Solution :`CH_(3)OH ` is ODD ONE because it is a noneelectrolyte WHEREAS the others are electrolytes . | |
| 4259. |
NaCl has a high melting point and boilingpoint as compared to carbon tetrachloride. |
| Answer» Solution :Sodium chloride has HIGH melting POINT and BOILINGPOINT because it has strong electrostatic forces of attraction between its ions hence more energy is required whereas carbon TETRACHLORIDE has weak VAN der Waals forces of attraction andhence energy required is less. | |
| 4260. |
NaCl conducts electricity in water, but it cannot conduct electricity in benzene. Give a reason |
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Answer» SOLUTION :(i) Water is a polar solvent. (ii) The particles responsible for condiction. (iii) The CHARACTERISTIC of solvent responsible for generating these particles. (iv) Comparison of characteristics of water and BENZENE |
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| 4261. |
NaCl + AgNO_(3) to AgCl + NaNO_(3) is an example of a _____ reaction . |
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Answer» |
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| 4262. |
Na, Mg and Al are the elements having one, two and three valence electrons respectively. Which of these elements (i) has the largest atomic radius, (ii) is least reactive ? Justify your answer stating reason for each. |
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Answer» Solution : (i) NA has the largest ATOMIC size because the atomic size decreases from left to right due to the increase in the NUCLEAR charge. (ii) Al is least REACTIVE because the tendency to LOSE electrons decreases from left to right. |
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| 4263. |
Na, Mg and Al are the elements of the same period of modern periodic table having one, two and three valence electrons respectively. Which of these elements (i) has the largest atomic radius, (ii) is least reactive ? Justify your answer stating reason for each case. |
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Answer» Solution :(a) NA has the largest atomic RADIUS because it has 11 PROTONS and 11 electrons, therefore least effective nuclear charge. (b) Al is least reactive because it has smallest atomic size due to13protons and13electrons,it has GREATER effective nuclear charge,therefore cannot lose electrons easilyhence it is least reactive. |
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| 4264. |
Na, Mg, and Al are the elements of the 3rd period of the Modern Periodic Table having group number 1, 2, and 13 respectively. Which one of these elements has the a) highest valency, (b) largest atomic radius, and (c) maximum chemical reactivity? |
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Answer» Solution :a) ELEMENTS having group number 1, 2, and 13 have a valency of 1, 2, and 3 RESPECTIVELY. So, AL has the highest valency. b] Atomic radius decreases along a period. So, Na has the largest atomic radius. c] Na has the maximum chemical reactivity since chemical reactivity decreases along a period. |
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| 4265. |
Na, Mg, Al and P belong to 3^(rd) period but are placed in first, second, thirteenth and fifteenth group. Number of shells occupied in Mg is three. What is the number of occupied shells in Na, Al and P. Give reasons for your answer. |
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Answer» Solution :It is three in Na, Al and P. Elements with the same NUMBER of OCCUPIED SHELLS are placed in same PERIOD. |
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| 4266. |
Na and Mg |
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Answer» belong to the same group. |
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| 4267. |
N_(2) , CH_(4) ,SO_(3) ,H_(2) O |
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Answer» SOLUTION :`N_(2)` Thefirstone is homoatomicand otherareheteroatomicmolecules . |
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| 4268. |
N_(2)+3H_(2)to2NH_(3), name the type of reaction. |
| Answer» SOLUTION :It is a COMBINATION REACTION. | |
| 4269. |
N_(2)+3H_(2)rarr 2NH_(3) (The atomic mass of nitrogen is 14, and that of hydrogen is 1) "1 mole of nitrogen "(………….g)+ "3 moles of hydrogen "(……….g)rarr "2 moles of ammonia "(……….g) |
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Answer» Solution :`N_(2)+3H_(2)rarr 2NH_(3)` 1 mole of `N_(2)=28g` 3 MOLES of `H_(2)=6g` 2 moles of `NH_(3)=34g` 1 mole of nitrogen `(28g)+3` moles of HYDROGEN `(6g)rarr2` moles of Ammonia (34g) |
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| 4270. |
N_(2)+3H_(2)rarr2NH_(3), name the type of reaction . |
| Answer» SOLUTION :It is a COMBINATION REACTION . | |
| 4271. |
n-Propyl alcohol and isopropyl alcohol are examples of |
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Answer» position ISOMERISM These are position isomers. |
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| 4272. |
n-factor of HNO_3 is |
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Answer» 1 |
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| 4273. |
Mukesh isstudent of class X. He lives in a big house. There is a big iron gate in the boundary wall of his house which was installed about one year back.For the last few days, Mukesh has been observing that red -brown pathces have appeared at some of the places on the iron gate. When Mukesh brought this development to the notice of his family, his sister, who is a student of class VI, said that the iron gate should be cleaned properly with sand paper to remove the red -brown patches and then smeared with oil on grease to protect it fro further damage. Mukesh did not agree with her and suggested a different teatment for the iron gate. Mukesh's father also agreed with his plan of action. (a) What are the red brown patches on the surface is iron gategt Name the process which leads to the formation of these patches. (b) What conditions are necessary for the formation of red-brown patches on the iron gate? (c) What har canbe done if this iron gate having red-brown patches is allowed to remain as such for a long time (without any treatment)? (d) Explain why this iron gate cannot be smeared with oil or grease to protet it form further damage? (e) What treatment do you think was suggested by Mukesh to protect the iron gate from further damage? How does this treatment work to protect the iron gate? (f) What values are displayedby Mukesh in this episode? |
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Answer» Solution :(a) The red brown patches on the surface of iron gate are of rust. The red brown patches are formed DUE to the rusting of iron (of the iron gate). (b) The conditionsnecessary for the rusting of iron to take place are (i) PRESENCE of airand (ii) presence of water (or moisture). In this case of rusting of iron gate damp air (or moist air) present around the iron gate provides both the conditions air and water (or moisture) required for the rusting of iron. (c) If this rusted iron gate is allowed to remain in this way, then the soft and porous rust will keep on falling from the surface of iron gate and then the fresh iron below will start rusting. The rusting of iron is a continuous process which will ultimately eat up the whole iron gate and make it useless. (d) The iron gate cannot be smeared with oil or grease hecause this oil and grease will spoil the HANDS and clothes of a person when the gate is opened or closed. MOREOVER, oil and grease can be washid away by rains. (e) Mukesh suggested the painting or iron gate. Whena coat of paint is applied to the surface of this iron gate, then air and moisture (present in moist air) cannot come in contact with the iron of iron gate and hence no rusting will take place. (f) The values displayed by Mukesh in this episode are (i) Keen Observation (ii) Awareness of rusting and conditions necesary for rusting (iii) Understand of correct method of prevention of rusting to be applied, and (iv) DESIRE to protect the iron gate of his house from further damage. |
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| 4274. |
Ms Joan was teaching metallurgy in a class. She taught her students how an intensely heated steel ingot when plunged into a water bath or an oil bath can acquire different properties. Then she asked the students the reason for using different cooling agents. What would be your answer for making use do different cooling agents? |
| Answer» Solution :Different baths are used for quenching steel for different use. Water and oil have different specific heat. Due to the difference in specific heat, dissipation of heat through the bath becomes different. Water has high specific heat. For this reason, dissipation of heat through water is more than that through oil. For DECREASING the dissipation of heat through water, HOT or boiled water is also used. Sudden cooling makes steel harder, and more BRITTLE. Hence, different baths provide different HARDNESS to the steel and MAKE it useful for different end uses. | |
| 4276. |
Most of the sources of energy we are represent stored solar energy. Which of the following is not ultimately derived from the sun's energy |
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Answer» GEOTHERMAL ENERGY |
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| 4277. |
Most of the reactions go faster at…. |
| Answer» Answer :A | |
| 4278. |
Most of the organic compounds are insoluble in……………….. |
| Answer» Answer :D | |
| 4279. |
Most of the metal oxides in water are ... |
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Answer» SOLUBLE |
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| 4280. |
Most of the detergents are biodegradable |
| Answer» SOLUTION :Most of the DETERGENTS are non-biodegradable. | |
| 4281. |
Most of the combination reactions are……….in nature. |
| Answer» SOLUTION :EXOTHERMIC | |
| 4282. |
Most of the carbon compounds release a large amount of ......... and ......... on burning. |
| Answer» SOLUTION :HEAT, LIGHT | |
| 4283. |
Mostof thecombinationreactionsare _______in nature . |
| Answer» SOLUTION :EXOTHERMIC | |
| 4287. |
Most carbon compounds |
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Answer» are POOR conductors of ELECTRICITY and have high boiling points. |
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| 4288. |
Moseley'speriodic table is based on atomic mass. |
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Answer» |
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| 4290. |
Write in ascending order, the radioactive elements according to the atomic number. N_(P) , Pu, U, Pa |
| Answer» SOLUTION :ATOMIC NUMBERS | |
| 4292. |
More and more positivechargesimpose a ____________ over the electrons. |
| Answer» SOLUTION :STRONG ATTRACTION | |
| 4294. |
Molecules in Solids |
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Answer» are FREE to MOVE about |
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| 4295. |
Molten sodium chloride and sodium chloride dissolved in water . |
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Answer» Solution :In molten sodium chloride , only `Na^(+) and CL^(-)` IONS are PRESENT ,whereas in an aqueous solution of sodium chloride four types of ions , NAMELY , `Na^(+) , Cl^(-) , H^(+) and OH^(-)` ions are present . On electrolysis of molten sodium chloride ,sodium of sodiumchloride , hydrogen GAS is produced at the cathode , and chlorine gas is produced at the anode , whereas a solution of sodium hydroxide is formed in the cell . |
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| 4296. |
Molten cryolite is mixed with molten alumina in the extraction of aluminium by electrolysis. Why ? Name the substances that are used as anode and cathode in this method. |
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Answer» Solution :(i) Molten cryolite acts as a solvent for alumina. FORMS an electrolyte at low temperature. (ii) High temperature electrolysis can be avioded, which prevents the loss of aluminium in the FORM of VAPOURS. (iii) Anode `rarr` Graphite rods (iv) Cathode `rarr` CARBON LINING. |
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| 4297. |
______moleculesare madeup ofatomsofthe sameelements . |
| Answer» SOLUTION :HOMOATOMIC. | |
| 4298. |
_______moleculesare madeup of atomsof differentelement . |
| Answer» SOLUTION :Hetroatomic . | |
| 4299. |
Moleculeof metalsin their vapour stateare usually _________. |
| Answer» SOLUTION :MONOATOMIC | |
| 4300. |
Molecule is the smallest particle that takes part in a chemical reaction. |
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Answer» |
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