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.
| 2201. |
Draw a sketch of Bohr’s model of an atom with three shells. |
| Answer» SOLUTION :For ANSWER CONSULT SECTION 4.5 (FIG no 4.9) | |
| 2202. |
Draw a sketch of Bohr's model of an atom with three shells. |
Answer» SOLUTION :
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| 2203. |
Draw a sketch of aluminium and chlorine atoms showing distribution of electrons in various shells. |
Answer» SOLUTION : 
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| 2204. |
A solution contains 40 ml of ethylalcohol mixed with 100 ml ofwater. What is the concentration of the solution in terms of volume by volume percentage. |
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Answer» SOLUTION :Volume of SOLUTE = 40 ML Volume of solvent = 100 ml Total volume of the solution = 40 + 100 = 140 ml Volume of vol. percentage = volume of sulute x 100/volume of solution `RARR""v//v% = 40 XX 100//140 = 28.57%` |
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| 2205. |
A solution contains 50 g of comon salt in 200 g of water. Calculate the concentration in terms of mass by mass percentage of the solution? |
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Answer» Solution :Mass of SOLUTE( SALT) =50G Mass of solvent (water) =200 g Mass of solution =Mass of solute + Mass of solvent `=50g+200g=250g` Mass PERCENTAGE of a solution = `=("Mass of solute")/("Mass of solution")xx100` `=50/250xx100=20%` |
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| 2206. |
Draw a diagram of Thomson's model of an atom. Why was it discarded ? |
Answer» SOLUTION : The REASONS for discarding Thomson.s model: (1) The arrangement of POSITIVE and negative charges as showm in the model was not possible because the opposite charges would attract each other and the atom as a whole would bc clectrically neutral. (2) The arrangement shown in the model could not explain chemical PROPERTIES of different ELEMENTS. |
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| 2207. |
Draw a comparison between the potential energy and kinetic energy of electrons in the 1^st orbits of hydrogen and He^+ ion. Also comment on the total energy of the electrons in the above cases. |
| Answer» SOLUTION :The electrons revolve round the nucleus with HIGH velocities to counter balance the nuclear force of attraction. As nuclear force of attraction in the `1^(st)` of `He^+` is more than that in H atom. Kinetic energy of electron in `He^(+)` is more (due to greater velocity ) than in H atom. When an electron approaches towards an atom, it LOSES potential works towards the force of attraction. The greater the force of attraction, the more is the loss of potential energy. Hence, the electron in `He^+` has LESSER potential energy than the electron in H atom. But the loss of PE is more SIGNIFICANT than the change in KE. Hence, total energy of helium is less that of hydrogen. | |
| 2208. |
A solution contain 50 g of a common salt in 200 g of water. Calculate the concentration in terms of mass by mass percentage of the solutions. |
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Answer» Solution :MASS of solute( SALT) =50g Mass of solvent (WATER) =200 g Mass of solution =Mass of solute + Mass of solvent `=50g+200g=250g` Mass percentage of a solution = `=("Mass of solute")/("Mass of solution")XX100` `=50/250xx100=20%` |
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| 2209. |
Don't you think that there is a relationship between ionization energy and metallic non metallic character? Is the element with highest ionization energy metallic or non metallic? |
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| 2210. |
A solution contains 40 g of common salt in 320 g of water. Calculate the concentration in terms of mass by mass percentage of the solution. |
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Answer» Solution :MASS of solute (salt) = 40 G Mass of solvent (WATER) = 320 g Mass of solution = Mass of solute + Mass of solvent = 40G + 320g = 360 g Mass percentage of solution = `("Mass of solute")/("Mass of solution")xx100` = `40/360xx100` = 11.1 % |
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| 2211. |
Does the shape of the liquid remain the same? |
| Answer» SOLUTION :No, the LIQUID will TAKE the SHAPE of the CONTAINER. | |
| 2212. |
A solutioncontains40 gof common saltdissolvedin 320g of watercalculate the mass concentration of the solution |
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| 2213. |
Does thepresence of ozone layer in the outeratmosphere cause rainfall ? |
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| 2215. |
A sample of water under supply was found to boil at 102^(@)C at normal temperature and pressure. It the water pure ? Will this water freeze at 0^(@)C ? Comment. |
| Answer» Solution :Under NORMAL temperature and pressure, the boilingpoint temperature of pure water is `100^(@)C`. The boiling point of `102^(@)C` MEANS that the given sample is IMPURE and has non-volatile impurities present. This impure sample will have FREEZING point temperature below `0^(@)C`. Please remember that the presence of impurities raises the boiling point temperature of a liquid and lowers its freezing point. | |
| 2216. |
A sample of water labelled A boils at 100^(@)C. A sample of water labelled B boils at 102^(@)C. Which sample of water will not freeze at 0^(@)C ? Why ? |
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Answer» Solution :The sample of water LABELLED B will not FREEZE at `0^(@)C`. The boiling point of pure water at 1 ATM is `100^(@)C`. The sample of water labelled B BOILS at `102^(@)C`. It means the water contains IMPURITIES. |
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| 2217. |
Does the evaporation of a liquid occur at the room temperature only ? |
| Answer» Solution :No, EVAPORATION of a LIQUID OCCURS at all temperatures below the BOILING point of the liquid . | |
| 2219. |
A sample of water mixed with a few drops of milk scatters light . What is the nature of the mixture ? |
| Answer» SOLUTION :The MIXTURE is a COLLOIDAL solution . | |
| 2221. |
A sample (A) of water boils at 100^@C whereas another same (B) of water boils at 101.2^(@)C. Identify the sample which will not freeze at0^@C . |
| Answer» SOLUTION :Sample (B) will not freeze at ` 0^(@)C` as it CONTAINS some IMPURITY . | |
| 2223. |
A salt dissolved in water can be recovered by a process known as .......... |
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| 2224. |
A research scholar, during his experiment came across an aliphatic hydrocarbon 'X'. In the process of identification of 'X' he passed 'X' through alka-: line KMnO_4. The solution became colourless. He found out the vapour density of the compound to be 34. Identify X and its succeeding hornologue 'Y' and also position isomers of straight chain ismoers. |
Answer» Solution :Molecular mass of x is 68 . It MAY be alkane or alkyne But it is impossible. SUCCEEDING homogolue Yis `C_6H_8` (hexyne) Position ISOMERS of X are 1-Pentyne, 2-Pentyne. Position iso-mers of Y are 1 Hexyne, 2 Hexyne and 3 Hexyne. |
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| 2225. |
Does an element containatoms of the same kind ? |
| Answer» SOLUTION :YES, but when ISOTOPES are not PRESENT . | |
| 2226. |
A reaction has an equilibrium constant of 22xx10^(-2) " mole"^(-1) L at a certain temperature. Which of the following equilibria corresponds to the above K_(c ) value ? |
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Answer» `NO_(2(G))+CO((g)) hArr NO_((g))+CO_(2(g))` |
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| 2227. |
A practical examination was being conducted for the students. The examiner, in the viva asked Julie the question 'Two salts X and Y are given to you. Salt 'X' is obtained by treating potassium with oxyacid of a non- metal with suffix 'ic' which has seven electrons in the 'M' shell which is the valence shell. Salt 'Y' is formed between lead and oxyacid of a non-metal with five electrons in its valence 'L' shell. Both the salts can give oxygen on thermal decomposition. Which salt do you prefer for the preparation of pure oxygen and why ? When she answered the question correctly, examiner was very much impressed and awarded her full marks. What was the answer that Julie gave ? |
| Answer» Solution :Non-metal with seven electrons in its valence shell (M shell) is chloride. The salt which gives oxygen on thermal decomposition should be an alkali metal chlorate. Non -metal with 5 electrons in its valence shell (L shell) should be nitrogen and the salt which can give oxygen on decomposition should be nitrate.Alkali metal chlorate gives only pure oxygen GAS, whereas bivalent ,i.e., LEAD metal nitrate gives amixture of oxygen and `NO_2` . SINCE it is difficult to separate `O_2` form this MIXTURE. the first one is a preferred method to get pure `O_2` gas. | |
| 2229. |
A piece of ice is heated and the temperature is monitored as afunction of time .Which of the following figures will justify the observation ? |
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| 2230. |
A physical science teacher said that workd is directly proportional to force and dispalcement .One of the student whoattended the time it foundation couse said that work done in removing an electron form a action is directly proportional to the charge on it the teacher appriected the student and explained the above concept what was her explantion ? |
| Answer» Solution :As the positive charge increase the EFFECTIVE nuclear charge on the OUTERMOST electron INCREASES so work DONE for removing an electron increases with the increaseso work done for removing an electron increases with the increase of charge on the cation | |
| 2231. |
Doctor advises to put strips of wet cloth on the forehead of a person having high temperature. Explain. |
| Answer» Solution :The WATER from the wet cloth will get heat energy from the foreheat and will EVAPORATE. Theis causes the fall in temperature. HENCE the person.s temperature comes downn and he feels COMFORTABLE. | |
| 2232. |
A phenomenon in which an element exists in different modification in same physical state is called _______ . |
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Answer» isomerism |
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| 2233. |
A particular atom has the 4th shell as its valenced sheel. if the difference between the number of electrons between K and N shells and L and M shells is zero, find the atomic number of the element and electronic congfiguration of its stable ion. |
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Answer» Solution :(i) Number of electrons in K and L SHELLS when N SHELL is the valence shell. (ii) calculation of number of electrons in K,L,M and N shells (iii) calculation of atomic number. (IV) number of electrons to be lost to form stable ion. (V) atomic number `=20` |
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| 2234. |
Isotopes of an element have : (a) the same physical properties (b) different chemical properties (c) different number of neutrons (d) different atomic numbers |
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| 2235. |
A naturally occuring sample of lithium contains 7.42%of ""^(6)Li and 92.58% ""^(7)Li. The relative atomic mass of ""^(6)Li is 6.015 and that of ""^(7)Li is 7.016. Calculate the atomic mass of a naturally occuring sample of lithium. |
| Answer» SOLUTION :ATOMIC MASS `=((6.015xx7.42)(7.016xx92.58))/(100)=6.94` | |
| 2236. |
Do protons originate from the anode ? |
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| 2237. |
A more hydrogenated oil is less rancid than less hydrogenated oil ,Give reasons. |
| Answer» Solution :Rancidity of oils is due to the persence of ACIDS and some other COMPOUNDS ,These COMPOUDS are formed nu the ATTACK of POSITIONS are converted to saturated positions .As a result oxidation of double is previnted . | |
| 2239. |
A molecule is made up of atoms . |
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| 2241. |
A mixture of X and Y on subjecting to paper chromatography gave the chromatogram 'A'. When the same mixture is subjected to heating, chromatogram B was obtained. What do you infer from the chromatograms ? |
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Answer» Solution :(i) principle involved in chromatography (ii) CHANGES observed in CHROMATOGRAM B (iii) reason for the CHANGE |
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| 2242. |
Do electrons in a particularorbit in an atom possess a fixed amount of energy ? |
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| 2243. |
A mixtureof two miscibleliquids whose boiling points differ by10^(@)C, can be separatedby a technique known as ................ |
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| 2244. |
A mixture of sulphur and carbon disulphide is |
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Answer» HETEROGENEOUS and shows Tyndall effect |
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| 2245. |
Do in representative elements do they include metalloids [eg. Si, Ge, As, Sb...) exhibiting the characteristics of metals and non metals? |
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| 2246. |
A mixture of SO_2, H_2 and Cl_2 can be separated by _____________ followedby _________. |
| Answer» SOLUTION :DIFFUSION, FRACTIONAL EVAPORTION ` | |
| 2248. |
Divide the class into two groups. Give 5 g of iron filings and 3 g of sulphur powder in a china dish to both the groups. Group I Mix and crush iron filings and sulphur powder. Group II Mix and crush iron filings and sulphur powder. Heat this mixture strongly till red hot. Remove from flame and let the mixture cool. Groups I and II Check for magnetism in the material obtained. Bring a magnet near the material and check if the material is attracted towards the magnet. Compare the texture and colour of the material obtained by the groups. Add carbon disulphide to one part of the material obtained. Stir well and filter. Add dilute sulphuric acid or dilute hydrochloric acid to the other part of the material obtained. Perform all the above steps with both the elements (iron and sulphur) separately. On adding dilute sulphuric acid or dilute hydrochloric acid, did both the groups obtain a gas? Did the gas in both the cases smell the same or different ? |
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Answer» Solution :Both the groups OBTAINED a gas. The SMELL of gas in both the cases is different. The gas obtained in CASE of Group I is colourless and ODOURLESS. (This is hydrogen gas.) The gas obtained in case of Group II is colourless with smell of ROTTEN eggs. (This is hydrogen sulphide gas.) |
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| 2249. |
A mixture of chloroform and watertaken in a separating funnel gest separated into two layers. Which one of thethese two substance is expected to occupy the upper layer and why ? |
| Answer» SOLUTION :WATER, because its DENSITY is LESS than that of CHLOROFORM . | |
| 2250. |
Divide the class into two groups. Give 5 g of iron filings and 3 g of sulphur powder in a china dish to both the groups. Group I Mix and crush iron filings and sulphur powder. Group II Mix and crush iron filings and sulphur powder. Heat this mixture strongly till red hot. Remove from flame and let the mixture cool. Groups I and II Check for magnetism in the material obtained. Bring a magnet near the material and check if the material is attracted towards the magnet. Compare the texture and colour of the material obtained by the groups. Add carbon disulphide to one part of the material obtained. Stir well and filter. Add dilute sulphuric acid or dilute hydrochloric acid to the other part of the material obtained. Perform all the above steps with both the elements (iron and sulphur) separately. Which group has obtained a material with magnetic properties ? |
| Answer» Solution :Group I OBTAINED a material with MAGNETIC PROPERTIES. | |
