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.
| 1301. |
Which of the following statements is wrong about detergents? |
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Answer» It is a sodium salt of long chain fatty acids |
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| 1302. |
Write the formula and name ofproduct in theReaction of acidified potassium dichromate with ethanol. |
| Answer» SOLUTION :`CH_3CH_2OH OVERSET([O])(to)CH_3CHO overset([O])(to) CH_3COOH` | |
| 1303. |
Which oxide of iron could be obtained on prolonged reaction of iron with steam? |
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Answer» SOLUTION :`Fe_3O_4` `3FE(s)+4H_2O(G) to Fe_3O_4(s)+4H_2(g)` |
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| 1304. |
Which one has the bigger size ? Na (11) or Cl (17), Cl (17) or F (9) |
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Answer» SOLUTION :Out of Na (11) and CL (17), sodium has bigger size. Out of Cl (17) and F (9), chlorine has bigger size. |
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| 1305. |
Thick sheets of pure copper are obtained at _______ in electrorefining |
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Answer» |
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| 1306. |
Write the common name of ethanoic acid. |
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Answer» FORMIC ACID |
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| 1307. |
when a small quantity of common salt is added to water |
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Answer» a suspension is FORMED |
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| 1309. |
Which of the following pair indicates isotopes? |
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Answer» `""_(17)C_(35),""_(17)Cl^(37)` |
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| 1310. |
What do you understand by solute and solvent ? |
| Answer» Solution :The SUBSTANCE which is present insmaller amount in a solution is called solute, while that present in LARGER amount is called solvent . | |
| 1311. |
Whatarecalledthermolysisreactions? |
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Answer» Solution :(i)Thereactantis deomposedby applyingheat. (ii )Themoleculesis dissociatedbyabsorptionn ofheatisknownas 'Thermolysis'or ' Thermaldecompositionreaction . AMercuryoxide(HGO)is decomposedintotwoelements (Hgand Oxygen ). A Mercuryoxide(HgO)is decomposedinto TWO ELEMENTS(Hg and Oxygen) . `2HgO _((s))overset("Heat") to2Hg_((l)) +O_(2(g))` Whencalciumcarbonateis heated ,it breaksdownintocalciumoxideand CARBONDIOXIDE (iii )It isa TYPEOF compoundtocompounddecomposition. `Ca CO_(3(s)) overset("Heat")toCaO_((s)) +CO _(2(g))` |
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| 1312. |
whiteenamelcoatingof ourteethis ________. |
| Answer» SOLUTION :calciumphosphate | |
| 1313. |
Write notes on various factors affecting solubility. |
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Answer» Solution :Factors affecting solubility : There are three main factors which govern the solubility of a solute. They are: (i) Nature of the solute and solvent (ii) Temperature (iii) Pressure (i) Nature of the solute and solvent: The nature of the solute and solvent plays an important role in solubility. Although water dissolves an enormous variety of substances, both ionic and covalent, it does not dissolve everything. The phrase that scientists often use when predicting solubility is “like dissolves like.” This expression means that dissolving occurs when similarities exist between the solvent and the solute. For example: Common salt is a polar COMPOUND and dissolves readily in polar solvent like water. Non-polar compounds are SOLUBLE in non-polar solvents. For example, Fat dissolved in ether. But non-polar compounds, do not dissolve in polar solvents, polar compounds do not dissolve in non-polar solvents. (ii) Effect of Temperature Solubility of Solids in Liquid: Generally, solubility of a solid solute in a liquid solvent increases with increase in temperature. For example, a greater amount of sugar will dissolve in warm water than in cold water. In endothermic process, solubility increases with increase in temperature. In exothermic process, solubility decreases with increase intemperature. Solubility of Gases in liquid : Solubility of gases in liquid decrease with increase in temperature. Generally, water contains dissolved oxygen. When water is boiled, the solubility of oxygen in water decreases, so oxygen escapes in the form of bubbles. Aquatic ANIMALS live more in cold regions because, more amount of dissolved oxygen is present in the water of cold regions. This shows that the solubility of oxygen in water is more at low temperatures. (iii) Effect of Pressure: Effect of pressure is observed only in the case of solubility of a gas in a liquid. When the pressure is INCREASED, the solubility of a gas in liquid increases. The common examples for solubility of gases in LIQUIDS are carbonated beverages, i.e. soft drinks, household cleaners containing aqueous solution of ammonia, formalinaqueous solution of formaldehyde, etc. 
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| 1314. |
Water gas consists of |
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Answer» water vapour and coal dust |
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| 1315. |
Which of the following hydrocarbon contains maximum number of covalent bonds? |
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Answer» `C_(3)H_(8)` 2. `H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-C-=C-H`………………..11 3. `H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-H`………………..13 4. `H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)(C)=underset(H)underset(|)(C)-H`………………..12 |
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| 1316. |
Write the name and molecular formula of the substance used in whitewashing the walls of the house. |
| Answer» Solution :Calcium HYDROXIDE is used for WHITE washing the WALLS of the HOUSE. Its molecular formula is `CA(OH)_(2)`. | |
| 1317. |
What is litmus solution ? |
| Answer» SOLUTION :It is a PURPLE dye which is EXTRACTED from a plant CALLED lichen | |
| 1318. |
When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of |
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Answer» a combination REACTION |
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| 1319. |
What happens when an iron nail is dropped in a solution of copper sulphate ? |
| Answer» SOLUTION :Copper GETS DEPOSITED on the SURFAE of the IRON nail. | |
| 1320. |
What change will you obsenre if you test soap with litmus paper (red and blue)? |
| Answer» Solution :It will CHANGE RED LITMUS into BLUE and no EFFECT will be there on blue litmus. | |
| 1321. |
What isacid rain ? |
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Answer» SOLUTION :(i) IFtheatmosphericairis pollutedwith oxidegasesof sulphur and nitrogen theygetdissolvedin therainWaterand makeitspHless than 7. (II )thusif thepHofrainwateris lessthan 7.thenit iscalledacidrain? (iii )whenacidrainflows intothe rivers itlowersthe PHOF theriverwateralso . (iv) Thesurvival of aquaticlifeinsuchrivers becomesdifficult. |
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| 1322. |
What is the difference between a true solution and a suspension ? |
| Answer» Solution :TH solute particles of a true solution do not SETTLE down on standing , WHEREAS the particles of a SUSPENSION do. | |
| 1323. |
Whichof thefollowingis notan "element+ element tocompound" typereaction? |
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Answer» `C_((S)) +O_(2(g))toC_(2(g))` |
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| 1324. |
What happens when (give balanced equations): Ethene is burnt in excess of oxygen. |
| Answer» SOLUTION :`C_2H_4(G) + 2O_2(g) to CO_2 (g) + 2H_2O (L) ` + HEAT | |
| 1325. |
The value of Avogadro's number is ………………. . |
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Answer» `6.023xx10^(-23)` |
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| 1326. |
Whatis the amount of silver deposited by passing 2 A for 20 min through molten silver nitrate ? If the same quantity of electricity is passed through a molten salt solution of gold, 1.6 g of gold is deposited at cathode, then find out its equivalent mass and oxidation state of gold in gold salt. (atomic weight of Au = 197, Ag = 108) |
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Answer» Solution :Number of gram equivalents `= ("CURRENT "xx" time")/(96500)` `= (2xx 20 xx 60)/(96,500) = 0.0248` Amount of silver deposited `= 0.0248 xx 108 = 2.68g` Let the equilvalent weight of Au be `E_(Au)`. `:. (E_(Au))/(E_(HG)) = (W_(Au))/(W_(Ag))` `rArr (E_(Au))/(108) = (1.6)/(2.68) rArr E_(Au) = 64.47` `:.` Oxidation state of gold `= ("Atomic weight")/("Equivalent weight")` `= (197)/(64.47)` `= 3.05 ~~3` Gold is present in `Au^(+3)` state in the salt |
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| 1327. |
When pressure is increased at constant temperature the solubility of gases in liquid ... |
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Answer» No CHANGE |
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| 1328. |
Which elements has The electronic configuration 2,8,2 ? |
| Answer» SOLUTION :MAGNESIUM has CONFIGURATION 2,8,2 | |
| 1329. |
what is saponification ? Give an example. |
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Answer» Solution :When an ESTER reacts with water in presence of a BASE, a salt of carboxylic acid and an alcohol are produced. Such a reaction is called saponification. E.g. when ethyl ethanoate is BOILED with a solution of sodium hydroxide, sodium ethanoate and ethanol are produced. `underset("Ethyl ethanoate")(CH_(3)COOC_(2)H_(5))+NaOH OVERSET("boiled")rarr underset("Sodium ethanoate")(CH_(3)COONa)+underset("Ethanol")(C_(2)H_(5)OH)` |
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| 1330. |
Which of the following statement is incorrect? |
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Answer» Metals like Cu, Ag, AU cannot diplace H from acids |
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| 1331. |
Which one of the following depict the correct representation of atomic radiusof an atom? |
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Answer» |
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| 1332. |
What are esters ? How they are prepared ? List two uses of esters. |
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Answer» Solution :Esters are the derivatives of carboxylic acids which contain COOR group The -OH group in an ACID is replaced by -O- azkyl or aryl group to form an ester. Esters are represented by the FORMULA `R_(1)COOR_(2)` where `R_(1)` and `R_(2)` represent an alkyl or aryl group. Preparation of esters : When carboxylic acids are HEATED with alcohols in the presence of an acid catalyst, esters are PRODUCED.  Uses of esters : (i) Esters are used in food as flavours and fragrances. (ii) In making of soaps (iii) Esters are used as solvents (vi) Esters are used in medicines. (V) Esters are used as emulsifying agents. |
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| 1333. |
Three elements P, Q, and R have successive atomic numbers with same period. If P > R > Q in terms atomic size. Predict the group of each element. Give reason. |
| Answer» Solution :Since P, Q, and R have successive atomic numbers, they lie in the same period. We know that even though atomic size DECREASES along a period, inert-gas elements have a slightly BIGGER atomic size than that of their PRECEDING element. Hence, R must be an inert gas. Hence, the group numbers of P. Q. and Rare 16, 17, and 18 RESPECTIVELY. | |
| 1335. |
Which one of the following represent Avogadro's law ? alpha |
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Answer» `V PROP (1)/(N)` |
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| 1336. |
Which compound is produced when quicklime reacts with water ? |
| Answer» SOLUTION :The compound PRODUCED is CALCIUM hydroxide (slaked LIME ). | |
| 1337. |
Two acids A and B have pH values 1 and 5 respectively. Which is the stronger acid, A or B? |
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Answer» |
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| 1338. |
Which period is the longest period in the Modern Periodic Table? |
| Answer» Solution :The sixth period is CALLED the longest period because it has MAXIMUM 32 ELEMENTS. | |
| 1339. |
Which of the following equations does not (do not ) represent correctly the physical states of the substances involved in the chemical reactions ? |
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Answer» `Zn(s)+H_(2)SO_(4)(1) to ZnSO_(4)(1) +H_(2)(g)` |
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| 1340. |
What is meant by water of crystallisation ? Explain that the crystalline salts contain water of crystallisation. |
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Answer» Solution :Water of crystallisation is a fixed number of water molecules present in one formula UNITOF a salt . One formula unit of copper sulphate contains five water molecules `(5H_(2)O)`. The water molecules which form part of the structure of a crystal are calledwater of crystallisation. When hydrated SALTS are heated strong heating , blue copper sulphate crystals turn WHITE (due to the loass of water of crystallisation) `underset(("Blue"))underset("copper sulphate")underset("Hydrated")(CuSO_(4).5H_(2)O)overset("heat")rarrunderset("White")underset("copper sulphate")underset("ANHYDROUS")(CuSO_4)+underset("Goes AWAY")underset("Water")(5H_2O)` Anhydrous copper sulphate turns blue on adding water. `underset(("White"))underset("copper sulphate")underset("Anhydrous")(CuSO_4)+underset("Water")(5H_2O)rarrunderset("(Blue)")underset("copper sulphate")underset("Hydrated")(CuSO_(4).5H_(2)O)` |
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| 1341. |
What happens to atomic radii in a group and period and why ? |
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Answer» Solution :Atomic radius is the distance between the centre of an atom and its outermost shell In a period atomic radius GENERALLY decreases from left to right. In a period there is a gradual increase in the nuclear CHARGE. Since valence electrons are added in the same shell, they are more and more strongly ATTRACTED towards nucleus. This GRADUALLY decreases atomic radii. Atomic radii increases In a group from top to bottom: As we go down a group, the number of shells increases and valence electrons are present ih a HIGHER shell and the distance of valence electrons from nucleus increases. Also, the number of filled shells between valence electrons and nucleus increases both the factors decrease the force of attraction between nucleus and valence electron. Therefore, atomic size increases on moving down a group |
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| 1342. |
Which of the following pairs are isotopes |
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Answer» OXYGEN and ozone |
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| 1343. |
Which gas in produced when dilute hydrochloric acid as added to reactive metal ? Write the chemical reaction when iron reacts with dilute H_(2)SO_(4). |
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Answer» Solution :`H_(2)` GAS `Fe(s) + H_(2)SO_(4)(AQ) RARR FeSO_(4)(aq) + H_(2)(g)` |
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| 1344. |
Which gas is usually liberated when an acid reacts with a metal ? |
| Answer» SOLUTION :HYDROGEN GAS. | |
| 1345. |
Write the number of covalent bonds in the molecule of propane, C_(3)H_(8). |
| Answer» SOLUTION :There are TEN covalent bonds: `H-underset(H)underset(|)OVERSET(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-H` | |
| 1346. |
What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise? |
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Answer» Solution :Function of receptors : They sense the external STIMULI such as heat or pain They also trigger an impulse in the sensory neuron which sends message to the spinal cord. When the receptors are damaged the external stimuli transferring signal to the brain are not FELT. For example in the case of damaged receptors if we ACCIDENTALLY touch any HOT OBJECTS we cannot feel the pain or heat. Receptors cannot procive the external stimuli of heat and pain |
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| 1347. |
When food containing fat or oil is not used and left for a long time, their smell and state changes.Name the process which is responsiblefor this change . List two methods to prevent or slow down the above change. |
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Answer» Solution :When food contaningfat or oil is not used and left over for a long time, their smell and state changes because FATS and OILS are getting slowly oxidised . This processis CALLED rancidity. Two METHODS which are used to slow down the oxidiation process are : (i) keeping food in airtight CONTAINER (ii) Flushing the bags containing food with nitrogengas. |
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| 1348. |
To which group does nitrogen (at. no. 7) belong in the periodic table? |
| Answer» SOLUTION :GROUP 15 | |
| 1349. |
The tendency to attract a shared pair of electrons towards itselfin a covalent bond is called _____________ |
| Answer» SOLUTION :ELECTRO NEGATIVITY | |
| 1350. |
What is 24-carat gold? How will you convert it into 18-carat gold? |
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Answer» Solution :24-carat GOLD is pure gold, Pure gold is very soft and not suitable for making jewellary. THEREFORE, to increase its hardness, it is alloyed EITHER with copper or silver. 18-carat gold is prepared by alloying 18 PARTS pure gold with 6 parts of either copper or silver. |
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