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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.
| 251. |
What is pH scale ? How is it used to identify the acidic and basic solution . |
Answer» Solution :pH SCALE is that scale which indicates whether the given solution is acidic, basic or neutral . On this scale , pH VALUE of VARIOUS SOLUTIONS lie between 0 to 14 . 
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| 252. |
Which of the following statements regarding orbit -als is false |
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Answer» 1S orbitals has one nodal region |
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| 253. |
Write electronic configuration of some elements. |
Answer» SOLUTION :
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| 254. |
Write the chemical equation involved in the following reaction Black and white photography. |
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Answer» SOLUTION :In black and white photography silver bromide on exposed to light DECOMPOSES to silver and bromine `2AgBr(s)OVERSET("sunlight")(to)2AG(s)+Br_(2)(G)` |
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| 255. |
When iron rod is kept dipped in copper sulphatesolution forsome time, a brown coating is formed on the iron rod. What change will be observed in the colour of the solution? Also write chemical equationfor the reaction involved. |
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Answer» Solution :Blue colour of the solutionn CHANGES to LIGHT green Raddish brown DEPOSIT is formed on the IRON nail. `Fe(S)+CuSO_(4)(aq) rarr Fe SO_(4)(aq)+Cu(s)` |
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| 256. |
What is the principle of an electric motor? |
| Answer» Solution :An ELECTRIC MOTOR is BASED on the principle that when a current is passed through conductor placed a uniformed magnetic FIELD it experiences a force which maker the conductor ROTATE. | |
| 257. |
Write any two events that occur during photosynthesis. |
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Answer» Solution :The three events that OCCUR during the process of PHOTOSYNTHESIS are : i) Absorption of light energy by CHLOROPHYLL. ii) Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen. iii) Reduction of carbon DIOXIDE iscarbohydrates. Role of stomata : These help in the gascous exchange between the plant and its atmosphere. Thus it assists in SUPPLY of carbondioxide essential for photosynthesis. |
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| 258. |
Velocity of an electron decreases as we go father from the nucels's justify. |
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Answer» Solution :According to Borh's angular momentum is quantised `mvr=(NH)/(2 pi)rArr v= (nh)/(2 pi MR.)` Form the above expression ,it is obvious that the VELOCITY decreases ,as we GO away from the nucles . It is due to the decrease in NUCLEAR forces of attrection. |
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| 259. |
What type of reaction is represented by the digestion of food in our body? |
| Answer» SOLUTION :DECOMPOSITION REACTION. | |
| 260. |
Which compound is used as an anti-freezer in automobile radiators? |
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Answer» ACETIC acid |
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| 261. |
What is an alloy ? Name the alloys and their constituents used for : (i) making aeroplanes (ii) soldering. |
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Answer» Solution :Alloy is a homogeneous mixture of two metals or a metal with a non-metal. (i) The alloy used for MAKING aeroplanes is duralumin : Duralumin : Al = 95%, CU = 4%, MG = 0.5%, Mn = 0.5% (ii) The alloy used for SOLDERING is solder : Solder : Pb = 50%, Sn = 50%. |
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| 262. |
Which of the following triads does not follow Dobereiner's law of triads? |
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Answer» (a) Li, Na, K of the atomic weights of Cu and Au, (Cu, Ag and Au) triad do not follow DOBEREINER's LAW of triads. |
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| 263. |
Which one of the following is most reactive towards water? |
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Answer» Sodium |
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| 264. |
What is the valency of halogens? |
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Answer» 7 |
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| 265. |
What is the volume occupied by 30 g of neon gas at 67^(@)C and750 mm of Hg? |
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Answer» Solution :According to theideal gas equation: PV = nRT(1) n= number of moles = weight/molecular weight = 30/20 Pressure = (750/760) atm [1 atm = 760 MM of Hg] T = (273+67) K = 340K From equation (1), V = nRT/P `V = 30/20 xx(0.0821 xx340)/((750//760))((g xx"L.atm/k.mol "xxK)/("g/mol "xx "atm"))=42.43 L` |
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| 266. |
What is the size of a particle of a solute in a suspension ? |
| Answer» SOLUTION :More than ` 10^(-5)` CM | |
| 267. |
Write the following componentsfor the electrolytic refining of a piece of impure copper : (i) The anode |
| Answer» SOLUTION :ANODE : A thickblock of IMPURE COPPER . | |
| 268. |
Which two gases are evolved when ferrous sulphate is heated ? |
| Answer» SOLUTION :SULPHUR DIOXIDE and sulphur TRIOXIDE. | |
| 269. |
Theslope of a given straight lime graph with constant temperature is found to be 0.2 L atm at 5 atm pressure. Calculate the volume of gas at that pressure. |
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Answer» <P> Solution :Slope = 0.2 L atm, P = 5 atm.ACCORDING to BOYLE's law, `P propto 1/V , P" constant " xx 1/V =" slope " xx 1/V, 0.2 xx 1/V = 5 rArr V = (0.2)/5 = 0.04` L |
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| 270. |
Which of the following pairs of elements are members of the same group?K and SrAr and ClSi and CaO and S |
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Answer» K and Sr |
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| 271. |
Write the number of C and H atoms in a molecule of the following:(a) Methane (b) Propane (c) Pentane (d) Decane |
| Answer» SOLUTION :`(a) CH_4 (B) C_3H_8 (C) C_5H_12 (d) C_10H_22` | |
| 272. |
What is the biological importance of pH ? |
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Answer» Solution :Biological importance (a) Our body works within the pH RANGE of 7.0 to 7.8. (B) Living organisms can SURVIVE in a NARROW pH Tange. (c) When the pH of rain water becomes less than 5.6, it is called acid rain. When this water flows into the rivers, the survival of aquatic life becomes difficult DUE to decrease in pH. |
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| 273. |
Which of the following properties of the elements can't be predicted from their position in the periodic table? |
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Answer» The FORMULA of its oxides |
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| 274. |
Write the balanced chemical equation for process of photosynthesis. When do desert plants take up carbondioxide and perform photosynthesis. |
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Answer» Solution : `6CO_(2)(g)+6H_(2)O(I) OVERSET("sunlight")to C_(6)H_(12)O_(6)(S)+6O_(2)(g)` In the desert plants, the stomata are open at night. They take `CO_(2)` at night and it is stored in the form of acid and is used during day time for PHOTOSYNTHESIS. |
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| 275. |
Whichof thefollowingcontainsmaximumnumberofmolecules |
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Answer» 1 GOF` CO_2` |
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| 276. |
What is meant by ductility ? |
| Answer» SOLUTION : The ABILITY of METALS to be DRAWN into thin wires (filaments) is CALLED ductility. | |
| 277. |
Which metals form hydrogen gas on reaction with very dilute nitric acid ? Write the equation of the reaction. |
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Answer» Solution : Magnesium (Mg) and manganese (MN) REACTS with very DILUTE nitric ACID and form hydrogen gas. `Mg(s)UNDERSET("very dilute")(2HNO_3) to Mg(NO_3)_2 + H_2` `Mn(s) + underset("very dilute")(2HNO_3) to Mn(NO_3)_2 + H_2` |
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| 278. |
The relative atomic mass of magneiusm based on C-12 scale is …………………. . |
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Answer» 24 g |
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| 279. |
Which elements have the largest and the smallest ? |
| Answer» SOLUTION :Lithium (Li) has largest atomic RADIUS (152 PM) and OXYGEN (O) has smallest atomic radius (77 pm). | |
| 280. |
Variations that confer an advantage to an individual organism only will survive in population. Justify. |
| Answer» Solution :Variations is the difference in the characters or traits among the individuals of a species SEXUAL reproduction of organisms produces variation. The variations produced in organisms during successive GENERATIONS gets accumulated in the ORGANISM the significance of variations shows up only if it continues to be inhertied by the offspring for SEVERAL generation. | |
| 281. |
Which of the following has a bond angle of 109^(@)? |
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Answer» `CO_(2)` 
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| 282. |
What are strong and weak acids ? In the following list of acids, separate strong acids from weak acids. Hydrochloric acid, citric acid, acetic acid, nitric acid, formic acid, sulphuric acid. |
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Answer» Solution :In aqueous solutions strong acids ionise completely and provide hydronium ions. On the other hand weak acids are partially ionised and an aqueous solution of same MOLAR concentration provides a much smaller concentration of `H_(3)O^(+)` ions. Strong acids - HYDROCHLORIC acid, sulphuric acid, nitric acid Weak acids - Citric acid, ACETIC acid, FORMIC acid |
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| 283. |
Which of the following properties is not a periodic property? |
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Answer» MELTING point |
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| 284. |
Which of the following is not an aliphatic hydrocarbon? |
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Answer» Ethene |
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| 285. |
What is meant by electric current? Name and define its SI unit. In a conductor electrons are flowing from B to A. What is the direction of conventional current? Give justification for your answer. |
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Answer» Solution :A steady current of 1 ampere flows through a conductor. Calculate the number of electrons that flows through any section of the conductor is 1 second (charge on electron `1.6 xx 10 ^(-19)` Coulomb) Electric current: The amount of charge Q flowing through a particular AREA of cross section in UNIT time "t. is CALLED clectric current, ie., Electrict current, `I = Q//t` SI unit of electric current is ampere One ampere of current is that current which flow when or.e coulomb of electric charge tlowing through a particular area of cross scction of the conductor is one second, i.e, `1A = 1 CS^(-1)` The direction of conventional current is A to B, ie., OPPOSITE to the direction of flow of electrons. In a metal, flow of electrons carrying negative charge constitucs the current. Direction of flow of electrons GIVEN the direction of electronic current by convention, the direction of flow of positive charge is taken the direction of flow of positive charge is taken as the direction of conventional current charge = q = ne For q = 1 Coulomb `(1C)/(1.6xx10^(-19)C)= (10^(19))/(1.6)= 6.25xx10^(18)` electrons |
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| 286. |
Transition elements and Inner transition elements |
Answer» SOLUTION :
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| 287. |
Which of the following will have maximum mass? |
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Answer» 0.1 mole of `NH_(3)` Mass of 1 mole of `NH_(3)=17g` `therefore"Mass of 0.1 mole of "NH_(3)=1.7g` (B) Mass of 1022 atoms of carbon `6.023xx10^(23)" c atoms of carbon" 6.023xx10^(23)" c atoms mass = 12 g"` `therefore"1022 atoms of C has the mass"` `=(12)/(6.023xx10^(23))xx1022=2.036xx10^(-20)g` (c ) Mass of 1022 molecules of `CO_(2)` `CO_(2)=` molar mass = 44 g `6.023xx10^(23)CO_(2)` molecules has the mass = 44 g `therefore 1022 CO_(2)` molecules has the mass `=(44)/(6.023xx10^(23))xx1022=7.466xx10^(-20)g` (d) 1 g of Fe `therefore` (a) 1.7 g of `NH_(3)` has the highest mass. |
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| 289. |
Which of these is a pairs of isobar |
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Answer» `6^(C^(12)) , 8^(O^(16))` |
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| 290. |
What are called thermolysis reactions? |
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Answer» Solution :A CHEMICAL reaction is a process in which old breaks up and new chemical bond get FORMED .Theromlysis chemical reactions is a special is as special type of chemical rections in which the reactant get decomposed by heat.For example, `CaCO_(3(s))overset("Heat")hArr CaO_((s))+CO_(2(g))` `2HgO_((s))overset("Heat")to2Hg_((1))+O_(2(g))` In these reactions heat is supplied to break the bonds ,so generally they are ENDOTHERMIC in nature. |
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| 291. |
When ethanol reacts with ethanoic acid in the presence of conc. H_(2)SO_(4), a substance with fruity smell is produced. Answer the following: (i) State the class of compounds to which the fruity smelling compounds belong. Write the chemical equation for the reaction and write the chemical name of the product formed. Sate the role of conc.H_(2)SO_(4). |
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Answer» SOLUTION :(i) Esters. CHEMICAL Equation :  Product.s chemical name-Ethyl ethanoate (ii) Cond. `H_(2)SO_(4)` acts as a dehydrating agent. (Helps in the removal of water formed in the reaction.) |
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| 292. |
The real bleaching agent present in bleaching powder is |
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Answer» chlorine |
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| 293. |
Which of the following is (are) not covalent compound(s) ? |
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Answer» C and H |
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| 294. |
What happens when (give only balanced equations and write the names of the reactants and products ) Methane reacts with two moles of chlorine gas. |
| Answer» SOLUTION :DICHLOROMETHANE `CH_2Cl_2`is FORMED | |
| 295. |
What happens when (give only balanced equations and write the names of the reactants and products ) Methane is mixed with oxygen and passed through a hot copper tube. |
| Answer» SOLUTION :METHANOL is FORMED | |
| 296. |
What is the mass ratio of iron and sulphur in which they combine to fromiron sulphide ? |
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Answer» `2:3` |
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| 297. |
Which among the following substances does not conduct electricity in its aqueous solution state? |
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Answer» glucose |
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| 298. |
When a small piece of dry sodium is put in water, it reacts vigorously to produce |
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Answer» nitrogen GAS |
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| 299. |
What happens when lead nitrate with potassium iodide solution? |
| Answer» Solution :Lead NITRATE solution when with potassium IODIDE solution ,a DEEP yellow precipitate of `pbI_(2)+2KItounderset("yellow precipitate(lead iodide)")(PbI_(2)darr+2KNO_(3))` | |
| 300. |
Which ions are present in hard water? |
| Answer» SOLUTION :Calcium `(CA^(2+))`, MAGNESIUM `(Mg^(2+))`` | |