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.
| 1951. |
Fog is a ............... dispersedin gas, whereas smoke is a ............. dispersed in ............... |
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| 1952. |
Fog and smoke are aerosols. What is the difference in their dispersed phases ? |
| Answer» Solution :The DISPERSED PHASE for FOG is LIQUID while that of SMOKE is solid. | |
| 1953. |
An element R belongs to IVA group and third period in the periodic table. Arrange the element that are palced below R and towards right in the periodic table in increasing order of atoic size and ionisation potential |
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Answer» SOLUTION :(i) identification of R (II) position of an element R in the perodic table (iii) compariosn of effect of nuclear charge on VALENCE elctons across a period and down the grup (iv) relation between nuclear charge size and ionsiation POTENTIAL |
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| 1954. |
Fluorination of methane is explosive. How do you account for this? How can fluorination of methanebe carried out? |
| Answer» Solution :Attack of fluorine on methane is highly exothermic reaction with very less activation energy . The high amounts of energy released in this step MAKE the fluorine MOLECULES to dissociate in greater number leading to a greater increase in the rate of reaction , which ultimately makes the reaction explosive .Hence the maxture of `C_H` and `F_2` when DILUTED with inert gas LIKE He or Ne or `N_2` , the rate of the reaction can be DECREASED .And also when the reaction is carried in a copper vessel copper being good conductor of heat, absorbs excess heat and thus makes the reaction to be moderate. | |
| 1955. |
Find the valency of Magnesium and Sulphur . |
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Answer» SOLUTION :Electronic configuration of magnesium is 2 , 8 , 2 . So VALENCY is 2. Electronic configuration of sulphur is 2 , 8 , 6 . So valency is 2 i.e. (8-6) |
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| 1956. |
Find the ratio by number of the atoms of elements in the molecules of water, ammonia and carbon dioxide. |
Answer» SOLUTION :The ratio by NUMBER of ATOMS for a WATER molecule can be found as follows:  The ratio by number of atoms for water is H:O = 2:1. `to` The ratio by number of atoms for an ammonia molecule can be found as follows:  `to` Thus, for ammonia, the ratio of atoms is N:H= 1:3 `to` The ratio by number of atoms for carbon dioxide molecule can be found as follows:  `to` Thus, for carbon dioxide, the ratio of atoms is С:O=1:2. |
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| 1958. |
Find the ratio by mass of the combining elements in the compounds -C_(2)H_(5)OH |
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Answer» SOLUTION :`C=2x12=24,H=6x=6, O=1x16=16` `C:H:O OP=24:6:16=12:3:8=` |
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| 1959. |
An element has fractional atomic mass. What does it indicate? |
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| 1960. |
Find the pair of elements having similar properties by applying Newlands' law of Octaves (Example : Mg & Ca): Set I : F, Mg, C, O, B Set II : Al, Si, S, Cl, Ca |
| Answer» SOLUTION :`{:("Set I :",F,Mg,C,O,B),("Set II :",CL,CA,SI,S,Al):}` | |
| 1961. |
An element has 2 electrons in the M shell. What is the atomic number of the element ? |
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Answer» Solution :There are 2 electrons in the M SHELL. It means that the K shell and L shell, which precede the M shell, are completely FILLED. The K shell can contain a maximum of2electrons and the L shell a maximum of 8 electrons. Thus , the ELECTRONIC configuration of the ELEMENT is `{:(K,L,M),(2,8,2):}` Hence, the total NUMBER of electrons in the atom is equal to `2+8+2=12` Atomic number=number of protons =number of electrons =12. |
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| 1962. |
Find the oxidation number of the elements in the following compounds. a. C in CO_2 b. Mn in MnSO_(4) c. N in HNO_(3) |
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Answer» SOLUTION :a. OXIDATION number of C in `CO_(2)` is +4 b. Oxidation number of Mn in `MnSO_(4)` +2 c. Oxidation number of N in `HNO_(3)` is +5. |
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| 1963. |
An element belongs to IIIAgroup and forth period in the modern perioidc table what could be the probable atomic number of that element ? |
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Answer» 23 `therefore` The ELEMENT in IIIA group and fourth period isGa (gallium) WHOSE atomic number is 31 |
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| 1964. |
Find the oxidation number of Mn in KMnO_(4) |
| Answer» Solution :`+7`. Since manganese atom is ATTACHED to four oxygen through three double bonds ONE SINGLE BOND. | |
| 1965. |
Find the oxidation number of Fe in FeO |
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| 1966. |
An electron having an angular momentum of 1.05xx10^(-34) joules jumps to another orbit such that it has an angular momentum of 4.20xx10^(-34) joules. Explain the possible transitions. |
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Answer» Solution :Angular momentum of an orbit. `mvr=(nh)/(2pi)` Initial angular momentum `=1.05xx10^(-34)` JOULES `1.05xx10^(-34)=(nxx6.625xx10^(-34))/(2xx3.14),n=1` The electron is PRESENT in the `1^(ST)` orbit originally. When the electron EXCITED, the angular momentum. `=4.20xx10^(-34)` joules. `4.20xx10^(-34)=(nxx6.625xx10^(-34))/(2xx3.14),n=4` An electron can lose energy when it is present in the `4^th` orbit and not from the `1^(st)` orbit. The possible transitions are `4to3,4to2,4to1,3to2,3to1 and 2to1` |
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| 1969. |
An atom X with atomic number 20 combines with atom Y with atomic numbers 8. Draw the dot structure for the formation of the molecule XY. |
Answer» Solution :Atom X is Calcium with atomic NUMBER 20 and atom Y is Oxygen with atomic number 8.
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| 1970. |
An atom of neon has a mass of 3.35 xx 10^(-23) g. how many atoms of neon are there in 20 g of the gas ? |
| Answer» Solution :Number of ATOMS = `("total mass")/("mass of 1 atom") = (20 g )/( 3.35 XX 10^(-23) g) = 5.97 xx 10^(23)` | |
| 1971. |
Find the mass of oxygen contained in 1 kg of potassium nitrate (KNO_(3)) . |
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Answer» Solution :Since 1 molecule of `KNO_(3)` contains 3 atoms of oxygen , 1 MOL of `KNO_(3)` contains 3 mol of oxygen atoms . `therefore` MOLES of oxygen atoms = `3 xx ` moles of `KNO_(3)` `= 3 xx (1000)/(101) = 29.7` (MOLECULAR mass of `KNO_(3) = 101`) `therefore` mass of oxygen = number of moles `xx` atomic mass = `29.7 xx 16 G = 475 . 2 g ` |
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| 1972. |
An atom of an element has two electrons in its outermostshell. Find the nature and value of charge on the ion producedwhen these tow electrons are lost . |
| Answer» SOLUTION :The ion will CARRY DOUBLE POSITIVE charge | |
| 1973. |
Find the mass of 1.5 moles of CaCO_(3). |
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Answer» Solution :Molar mass of `CaCO_(3) = 40 + 12 + (3 XX 16)` = `40 + 12 xx 48` = 100 g Mass = `"molar mass" xx "NUMBER of moles"` = `100 xx 1.5` = 150 g The mass of 1.5 moles of `CaCO_(3)` = 150 g. |
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| 1974. |
Find the mass of 10 moles of sodium sulphite (Na_(2)SO_(3)) (b)Calculate the number of molecules in 8g of oxygen gas. (c )Convert 22g of CO_(2) into moles. |
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Answer» Solution :`"Molar mass of "Na_(2)SO_(3)=2xx23+32+3xx16` `=46+32+48=126g` `"Mass of 10 MOLES of "Na_(2)SO_(3)=126xx10=1260g` (b)=Molar mass of oxygen `(O_(2))`=32G Molar mass of `(O_(2))`=32g 32g of oxygen=1 mol 8g of oxygen`=(1"mol")xx((8g))/((32g))=0.25"mol"` (C )`"Molar mass of "CO_(2)=12+2xx16=44g` 44g of `CO_(2)`=1 mol 22g of `CO_(2)=(1"mol")xx((22g))/((44g))=0.5"mol"` |
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| 1975. |
An atom contains the same number of protons and electrons. |
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| 1976. |
Find the mass in grams out of 2.42 mol of zinc . |
| Answer» Solution :The atomic mass of zinc = 65.41 .Hence , the mass of 1 MOL = 65.41 GRAMS of zinc . THUS , the mass of 2.42 mol zinc = `65.41 xx 2.42` G = 158.29 g | |
| 1977. |
An alpha particle is |
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Answer» A hydrogen NUCLEUS |
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| 1978. |
Find out whether elements familiar to you are present in these groups? |
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| 1979. |
Find out the ratio by mass of combinating elements in the following compounds (a) MgCO_(3) (b) CH_(3)OH (c) CaCl_(2) (d)H_(2)SO_(4) (e)Ca(OH)_(2)(f)NH_(2) |
Answer» SOLUTION :
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| 1981. |
Find out the position allotted to the elements with atomic number 58-71? |
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| 1982. |
Find out the period and group of the element in the periodic table with atomic number 14. |
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| 1984. |
Find out the molecular mass of sulphuric acid . |
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Answer» Solution :The molecular FORMULA of sulphuric ACID is `H_(2)SO_(4)` . Atomic MASS of H = 1 Atomic mass of O = 16 . Atomic mass of S = 32 `therefore` molecular mass of `H_(2)SO_(4)` = `(2 XX ` atomic mass of H) + (1 `xx` atomic mass of S) + ( 4 `xx` atomic mass of O) `= (2 xx 1) + ( 1 xx 32 ) + ( 4 xx 16) = 2 + 32 + 64 = 98.` So , molecular mass of `H_(2)SO_(4)` = 98 |
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| 1985. |
Find out the maximum number of electrons that can be accommodated in the third shell of an atom. |
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| 1986. |
An alloy is considered as a mixture. |
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Answer» SOLUTION :The components PRESENT in an alloy are METAL or non-metal. These components possess their fundamental properties. It can possess the variable composition. HENCE, an alloy is considered as a mixture. |
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| 1987. |
Find how ionization energy changes with increase in nuclear charge? |
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| 1988. |
Amoung the followingsubstancewhich one is a mixture ? |
| Answer» ANSWER :D | |
| 1989. |
Fill in the following table according to the type of bonds formed in the given molecule CaCl_(2).H_(2)O, CaO, CO,KBr,HCl,C Cl_(4), HF, CO_(2),Al_(2)Cl_(^) |
Answer» SOLUTION :
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| 1990. |
Fill in the blanks in the following statements: (a) Rutherford'salpha - particle scattering experiment led to the discovery of the ........ .(b) Isotopes have same......but different ....... .(c) Neon and chlorine have atomic numbers 10 and 17 respectively. Their velencies will be ...... and ......respectively (d) The electronic configuration of silicon is......and that of sulphur is........... . |
| Answer» SOLUTION :(a) nucleus (B) ATOMIC numbers ,mass numbers (c ) zero and one (d) 2,8,4 and 2,8,6 | |
| 1991. |
Among white phosphorous which is more preferable for use in match sticks ? Give reasons in support of your answer. |
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Answer» SOLUTION :(i) COMPARISON of structure of WHITE phosphorous and red phosphorous (ii) comparison of IGNITION of temperature of white phosphorous and red phosphorous (III) relating ignition temperature to usage as much sticks. |
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| 1992. |
Fill in the blanks in the following table based on the concept of water of cystallisation. |
Answer» SOLUTION :
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| 1993. |
Fill in the blanks : Carbonates of ________ and _______ do not produce carbon dioxide on heating. |
| Answer» SOLUTION :SODIUM and POTASSIUM | |
| 1994. |
Among third period elements halogen and alkaline earth metals are respecively |
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Answer» CI,Na |
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| 1995. |
Fill in the blanks : Carbon monoxide is absorbed in ________ while hydrogen is adsobred by ________ . |
| Answer» SOLUTION :AMMONIACAL CUPROUS CHLORIDE, PALLADIUM | |
| 1996. |
Fill in the blanks (a) Evaporation of a liquid at room temperature leads to a …… effect . (b) Atroom temperature the forces of attraction between the particles of solid substances are …. Than those which exist in the gaseous state. (c) The arrangement of particles is less ordered in the ... state. However, there is no order in the ..... state. (d)....... is the change of gaseous state directly to solid state without going through the ....... state. (e) The phenomenon of changes of a liquidinto the gaseous state at any temperature below its boiling point is called ...... |
| Answer» Solution :(a) COOLING (b) strogner (c ) LIQUID, GASEOUS (d) FREEZING, liquid (E ) evaporation. | |
| 1997. |
Among the following the odd pair is …. |
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Answer» `""_(8)^(18)O, ""_(7)^(37)Cl` |
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| 1998. |
Fill in the blanks. (a) A colloid is a ……… mixture and its components can be separated by the technique known as ……… . (b) Ice, water and water vapour look different and display different ………. Properties but they are ……. thesame. (c) A mixture of chloroform and water taken in a separating funnel is mixed and left undisturbed for some time. The upper layer in the separating funnel will be of ........ and the lower layer will be that of ....... . (d) A mixture of two or more miscible liquids, for which the difference in the boiling points is less than 25 K can be separated by the process called .......... . (e) When light is passed through water containing a few drops of milk, it shows a bluish tinge. This is due to the ...... of light by milk and the phenomenon is called .......... . This indicates that milk is a........... solution. |
| Answer» Solution :(a) heterogenous, centrifugation(b) fractional distillation (E) SCATTERING, Tyndall effect, COLLOIDAL (ALSO called emulsion). | |
| 1999. |
Among the following ______ is a mixture |
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Answer» COMMON salt |
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| 2000. |
Fill in the blanks : ________ is added to very dilute nitric acid to produce H_(2). |
| Answer» SOLUTION :MAGNESIUM | |