2599 + Interview Questions in Chemistry in Class 9 Page 9 InterviewSolution

401.	What is the general trend in the variation of ionisation energy on moving across a period from left to right?
Answer» ANSWER :IONIZATION ENERGY INCREASES

Discussion

402.	What is the process called in which a gas is transformed into a liquid ?
Answer» SOLUTION :LIQUEFACTION

Discussion

403.	When the size of an atom increases, does the attraction of the nucleus on the outermost electron increase or decrease?
Answer» ANSWER :DECREASE

Discussion

404.	What is the mass of (a) 0.2 mole of oxygen atoms? (b) 0.5 mole of water molecules?
Answer» Solution :(a) MOLAR mass of oxygen atom = 16 g Mass of oxygen atoms = `"molar mass" xx "number of moles"` `= 16 xx 0.2` = 3.2 g (B) Molar mass of water MOLECULE `(H_(2)O) = (2 xx 1) + 16` = 2 +16 = 18 g Mass of water molecule = `"molar mass" xx "number of moles"` `= 18 xx 0.5` = 9 g

Discussion

405.	Which of the following shows the correct order of increasing intermolecularforces of attractions ?
Answer» water ` LT ` Air ` lt ` PETROL `lt ` KEROSENE Petrol `GT ` Water ` gt ` Kerosene ` gt` Air Water` gt` Petrol ` gt` Air ` gt` Kerosene Air ` lt` Petrol `lt` Kerosene ` lt` Water ANSWER :D

Discussion

406.	Which of the following statements is false forgaseous matter?
Answer» INTERMOLECULAR FORCE is highest No definite shape No definite volume It is compressible Answer :A::C

Discussion

407.	Which of the following will show Tyndall effect ? (a) Salt solution, (b) Milk, ( c) Copper sulphate solution and (d) Starch solution.
Answer» Solution :MILK and starch solution will SHOW Tyndall EFFECT.

Discussion

408.	Whatisthe volumepecent of a solution prepared by dissolving15 cm^(3)of methanol in 100 cm^(3)of ethanol?
Answer» Solution :Volumeof METHANOL = `15 CM^(3)` Volumeof ethanol = `100 cm^(3)` `therefore` volumeof the solution `= (15+100)=115 cm^(3)` `therefore` volumeper centof solution= `(15)/(115)xx100=13.04%`

Discussion

409.	What are the various explosies that can be prepared from ammonia ?
Answer» SOLUTION :N/A

Discussion

410.	What is formula unit mass ?
Answer» SOLUTION :The FORMULA UNIT mass of a substance is a sum of the atomic masses of all atoms in a formula unit of a COMPOUND. This is used for substances whose constituent particles are ions.

Discussion

411.	The scientists now say that there are actually five states of matter A, B, C, D and E. The state A has a fixed volume but no fixed shape. The state B can be compressed very easily by applying pressure and state C has a fixed shape as well as a fixed volume. The state D is a mixture of free electrons and ions whereas state E is named after an Indian scientist and a famous physicist.(a)Name the physical state (i) A (ii) B (iii) C (iv) D, and (v) E.(b) Name one substance belonging to state C which can directly change into vapours on heating. What is this process known as ?(c ) Name one substance which normally belongs to state B but whose solid form changes directly into gaseous state.(d)Name the most common substance belonging to state A.(e) Which state to matter makes the sun and other stars to glow ?
Answer» Answer :(a) (i) LIQUID(II) Gas (iii) Solid (iv) Plasma(V) Bose-EinsteinCondensate(BEC)(b) Ammonium chloride ; SUBLIMATION (c ) CARBON dioxide (d) Water (e) D (plasma)

Discussion

412.	Which seperation techniqueswill you apply for the Seperation of thedifferentPigments froman extractof flowerPetals?
Answer» SOLUTION :Chormatography

Discussion

413.	Which among the following is true regarding dynamic equilibrium ?
Answer» The composition of reactants VARIES but not PRODUCTS. The composition of products varies but not reactants. Rate of forward and backward REACTIONS proceeds with different speeds. Rate of forward and backward reactions proceeds with EQUAL speeds. Solution :At dynamic equilibrium rate of forward and backward reaction are equal.

Discussion

414.	Which of the following pairs make a homogeneous mixture ?
Answer» SAND and WATER SOIL and water OIL and water Glucose and water Answer :D

Discussion

415.	When water at 0^(@)C freezes to form ice at the same temperature of 0^(@)C, then it :
Answer» ABSORBS some heat releases some heat neither absorbs nor releases heat absorbs exactly `3.34 xx 10^(5) J//kg` of heat ANSWER :B

Discussion

416.	What is the mass of 5 mol of ammonia ?
Answer» Solution :MASS of AMMONIA = number of MOLES `xx` gram-molecular mass = `5 xx 17 G = 85 g`.

Discussion

417.	What kind of pollution is produced when some undesirablematerials are added to water bodies or some desirablematerials are taken away from them ?
Answer» AIR POLLUTION Water pollution SOIL pollution NOISE pollution Answer :B

Discussion

418.	When two pieces of ice are pressed together, they form a single lump. Explain
Answer» Solution :When two pieces of iceare pressed together, they formed a single lump, it is due to regelation. When two ICE cubes are pressed together, the ice at the interface MELTS due to the application of PRESSURE and when the pressure is released, it SOLIDIFIES again thereby JOINING the two ice cubes.

Discussion

419.	Two contains A and B are filled with the same amount of chlorine gas Limited amount eof methane is passed into cantainer 'A' and excess of methane into container 'B' Identify the products formed in A and B.Give reason in support of your answer
Answer» Solution :If LIMITED amount of methane is passed through the container 'A' methyl chloride is formed first .As the amount of methyl chlorideexceeds the CONCENTRATION of methnechlorine attacks on methly chloride rather than methane forming methylene chloride which in similar WAY gets chlorinated finally forming`"CC"l_4` The end product is a mixture f methane mthyl chloride methylene chalride ,trichloromehane and corbone TETRACHLORIDE. Insecond case if ecess of methane is passed ,only methyl chloride is formed . `underset("(excess)""" "Methyl chloride")(CH_4+Cl_2rarrHCl+CH_3Cl)`

Discussion

420.	What fraction of the density of normal air should a gas of extremely low density be cooled to super low temperature?
Answer» ONE hundred Ten lac One lac Thousand Answer :A::C

Discussion

421.	What is diffusion?
Answer» Solution :The process by which the PARTICLES of two DIFFERENT types of MATTER mix on their own is calld diffusion.

Discussion

422.	What are four types of salts?
Answer» Solution :Normal Salts (i) A normal salt is obtained by complete neutralization of an acid by a base, `NaOH+HCl to NaCl+H_(2)O` (ii) Acid Salts It is derived from the PARTIAL replacement of hydrogen ions of an acid by a metal. When a calculated amount of a base is added to a polybasic acid, acid salt is obtained `NaOH+H_(2)SO_(4) to NaHSO_(4)+H_(2)O` (iii) Basic Salts Basic salts are FORMED by the partial replacement of hydroxide ions of a diacidic or triacidie base with an acid radical. `Pb(OH)_(2)+HCl to Pb(OH)Cl+H_(2)O` (iv) Double Salts Double salts are formed by the combination of the saturated solution of two simple salts in equimolar RATIO followed by crystallization. For example, Potash alum is a MIXTURE of potassium sulphate and aluminium sulphate.`KAl(SO_(4))_(2.12) H_(2)O`

Discussion

423.	Why are one-time use and throwaway plastics harmful?
Answer» Solution :Use and throwaway plastics cause short and long-term environmental damage as they are difficult to RECYCLE. They stay in environment for over 1000 years. These block DRAINS and POLLUTE water bodies. One-time use plastic causes health PROBLEMS for humans, plants and ANIMALS. Some examples are plastic carry bags, cups, etc.

Discussion

424.	What are the achievements and the limitaiton of newland's classification ?
Answer»

Discussion

425.	Which of the following is an example of colloid in which dispersed phase is liquid and dispersing medium is solid ?
Answer» Chesse Butter Jelly All the given Answer :A::B::C::D

Discussion

426.	There are ..... electrons in the outermost orbit of chlorine atom.
Answer» ANSWER :7

Discussion

427.	Write the distribution of electrons in carbon and sodium atoms.
Answer» Solution :ATOMIC number of carbon is 6. `therefore` number of protons= 6 Number of protons = number of ELECTRONS. So, it has 6 electrons. K shell - 2 electrons L shell - 4 electrons atomic number of sodium is 11 . `therefore ` number of protons = 11 number of protons = number of electrons So, it has 11 electrons. K shell - 2 electrons L shell - 8 electrons M shell - 1 electron

Discussion

428.	Which of the following processes does (do) not participate in the carbon cycle ?
Answer» PHOTOSYNTHESIS RESPIRATION Osmosis DIFFUSION ANSWER :C

Discussion

429.	When lon is formed from the atom, number of which subatomic particle(s) changes ?
Answer» PROTON NEUTRON ELECTRON Proton and neutron ANSWER :C

Discussion

430.	What is the relationship between the rate of chemical reaction and temperature?
Answer» ANSWER :When TEMPERATURE increases RATE of chemical reaction ALSO increases.

Discussion

431.	Write the applications of Nanochemistry.
Answer» Solution :Some applications of Nanochemistry are: `to` The metallic nanoparticles can be used as very ACTIVE catalysts. `to` Chemical sensors from nanoparticles and nanowires enhance the sensitivity and sensor selectivity. `to`Nano coatings and nanocomposites are FOUND useful in making variety of products such as sports equipment, bicycles and automobiles etc. `to` These are used as novel UV- blocking coatings on GLASS bottles which protect beverages from being damaged by sunlight. `to` Nanotechnology is being applied in the production of synthetic skin and implant surgery. `to` Nanomaterials that conduct electricity are being used in electronics as minute conductors to produce circuits for microchips. `to` Nanomaterials have extensive applications in the preparation of cosmetics, DEODORANTS and sun screen lotion and they are used to improve moisfurizers WITHOUT making them too oily. `to` Nanoparticle substances are incorporated in fabrics to prevent the growth of bacteria. `to` Biomedical devices like drug infusion pumps, microneedles and glucometer are made from nanomaterials. `to` Nanochemistry is used in making space, defence and aeronautical devices.

Discussion

432.	The total number of inner transition elements is __________
Answer» 14 28 20 15 Answer :B

Discussion

433.	What are the pollutants produced by the burning of petrol ?
Answer» SOLUTION :(i) Carbon MONOXIDE , (II) unburnthydrocarbons , (iii)alcohols , (IV) acids , (v) lead PARTICLES, etc.

Discussion

434.	What is electrovalency?
Answer» Solution :The NUMBER of electrons that an ATOM of an element loses or GAINS to form an ELECTROVALENT BOND is called electrovalency.

Discussion

435.	Which of the following factors affect the equilibrium constant ?
Answer» concentration pressures catalyst temperature Answer :D

Discussion

436.	Which of the following concepts is not of Dalton.s atomic theory?
Answer» Atoms cannot be CREATED or destroyed. Atoms of different ELEMENTS have different volumes, masses and chemical properties. Atoms of same element combine in same ratio and form various compounds. Atom is a very TINY INDIVISIBLE particle. Solution :Atoms of same element combine in same ratio and form various compounds.

Discussion

437.	What do you observe : Iodine crystals are heated strongly in a test tube.
Answer» Solution :Iodine CRYSTALS SUBLIME to VIOLET vapours which soon settle on the cooler PART of the test tube to FORM a violet solid deposit.

Discussion

438.	What are the features of Rutherford's model of an atom ?
Answer» Solution :The main features of Rutherford.s model of an atom are as follows: (1) There is a POSITIVELY charged centre inthe atom called the nucleus. (2)Most of the mass of an atom ls concentrated in the nucleus. (3) The electrons around the nucleus in CIRCULAR paths. (4) The size of the nucleus is very small as compared to the size of the atom.

Discussion

439.	Write the electronic configuration of any one pair of isotopes and isobars.
Answer» Solution :(i) Electonic ocnfiguration of pair of isotopes : For answer consult QUESTIONS No12 (All are isotiopes) (ii) Electonic configureation of pair of ISOBARS: Isorbars have same mass number but different atomic number .For EXAMPLE , elements calcium and ARGON are isobars: CA(z=20):2,8,8,2 Ar (Z=18):2,8,8. Please note that both the elements have mass number (a) equal to 40.

Discussion

440.	Which component of the mixture (Iron + Sulphur) reacts with dilute hydrochloric acid to evolve a gas ? Name the gas which is evolved during the reaction.
Answer» Solution :The component iron of the GIVEN mixture reacts with dilute HYDROCHLORIC ACID. During the REACTION hydrogen gas is evolved.

Discussion

441.	What type of oxies do metals form ?
Answer» SOLUTION :N/A

Discussion

442.	What is ratio by mass of magnesium and calcium obtained when the electrolysis of their respective chlorides are carried out in the molten state, if the number of moles of both the chlorides taken are same ?
Answer» SOLUTION :`{:(MgCl_(2) to MG^(2+) + CL^(-),, CaCl_(2) to Ca^(2+) + Cl^(-)),(Mg^(2+) + 2e^(-) to Mg,, Ca^(2+) + 2e^(-) to Ca):}` Ratio of mass `=24 : 40 = 3 : 5`

Discussion

443.	Which of the following compositosn is used as a fertiliser ?
Answer» `CaCN_2+C` `CaC_2+C` `Ca_3N_2+C` `AIN+C` SOLUTION :N/A

Discussion

444.	Which one of the following doesn't come under zero group?
Answer» he K ne ar ANSWER :B

Discussion

445.	What is the mass of an atom ?
Answer» Solution :The MASS of an atom is the sum of the masses of PROTONS and NEUTRONS present in the nucleus.

Discussion

446.	Two gases cannot diffuse into each other.
Answer» ANSWER :F

Discussion

447.	Which of the followingmaterialsfall inthe category of a " Pure Substances" ? (a)Ice (b) Milk ( c) Iron (d) hydrochloricacid ( e)Calcium Oxide ( f)Mercury (g)Bricks (h) Wood (i) Air
Answer» Solution :PURE Substances:- Iron ,Ice , Hydrochloricacid , CALCIUM oxide,and MERCURY

Discussion

448.	Which separation techniques you will apply for the separation of the following mixtures ? (a) Oil from water (b) Camphor from sand (c ) Sodium chloride from its solution in water
Answer» Solution :(a) By the use of a SEPARATING funnel. (b) With the help of SUBLIMATION TECHNIQUE. (c ) By CRYSTALLISATION technique.

Discussion

449.	Which of the following equilibrium shifts in the backward direction by applying high pressure ?
Answer» `N_(2)O_(4)(g)_(to)^(larr)2NO_(2)(g)` `H_(2(g))+Cl_(2(g)_(to)^(larr))2HCL(g)` `N_(2(g))+3H_(2(g)_(to)^(larr))2NH_(3(g))` `PCl_(2(g))+Cl_(2(g)_(to)^(larr))PCl_(5(g))` Answer :A

Discussion

450.	Turpentine oil when exposed to an atmosphere of chlorine ignites with a black sooty flame. Justify.
Answer» SOLUTION :(i) COMPOSITION of turpentine (ii) REACTION of chlorine with one of the components of trupentine oil (iii) product formed in the above reaction (iv) identification of the CONSTITUENT of turpentine oil which is responsible for the black sooty flame.

Discussion

Explore topic-wise InterviewSolutions in .

What is the general trend in the variation of ionisation energy on moving across a period from left to right?

What is the process called in which a gas is transformed into a liquid ?

When the size of an atom increases, does the attraction of the nucleus on the outermost electron increase or decrease?

What is the mass of (a) 0.2 mole of oxygen atoms? (b) 0.5 mole of water molecules?

Which of the following shows the correct order of increasing intermolecularforces of attractions ?

Which of the following statements is false forgaseous matter?

Which of the following will show Tyndall effect ? (a) Salt solution, (b) Milk, ( c) Copper sulphate solution and (d) Starch solution.

Whatisthe volumepecent of a solution prepared by dissolving15 cm^(3)of methanol in 100 cm^(3)of ethanol?

What are the various explosies that can be prepared from ammonia ?

What is formula unit mass ?

Which seperation techniqueswill you apply for the Seperation of thedifferentPigments froman extractof flowerPetals?

Which among the following is true regarding dynamic equilibrium ?

Which of the following pairs make a homogeneous mixture ?

When water at 0^(@)C freezes to form ice at the same temperature of 0^(@)C, then it :

What is the mass of 5 mol of ammonia ?

What kind of pollution is produced when some undesirablematerials are added to water bodies or some desirablematerials are taken away from them ?

When two pieces of ice are pressed together, they form a single lump. Explain

Two contains A and B are filled with the same amount of chlorine gas Limited amount eof methane is passed into cantainer 'A' and excess of methane into container 'B' Identify the products formed in A and B.Give reason in support of your answer

What fraction of the density of normal air should a gas of extremely low density be cooled to super low temperature?

What is diffusion?

What are four types of salts?

Why are one-time use and throwaway plastics harmful?

What are the achievements and the limitaiton of newland's classification ?

Which of the following is an example of colloid in which dispersed phase is liquid and dispersing medium is solid ?

There are ..... electrons in the outermost orbit of chlorine atom.

Write the distribution of electrons in carbon and sodium atoms.

Which of the following processes does (do) not participate in the carbon cycle ?

When lon is formed from the atom, number of which subatomic particle(s) changes ?

What is the relationship between the rate of chemical reaction and temperature?

Write the applications of Nanochemistry.

The total number of inner transition elements is __________

What are the pollutants produced by the burning of petrol ?

What is electrovalency?

Which of the following factors affect the equilibrium constant ?

Which of the following concepts is not of Dalton.s atomic theory?

What do you observe : Iodine crystals are heated strongly in a test tube.

What are the features of Rutherford's model of an atom ?

Write the electronic configuration of any one pair of isotopes and isobars.

Which component of the mixture (Iron + Sulphur) reacts with dilute hydrochloric acid to evolve a gas ? Name the gas which is evolved during the reaction.

What type of oxies do metals form ?

What is ratio by mass of magnesium and calcium obtained when the electrolysis of their respective chlorides are carried out in the molten state, if the number of moles of both the chlorides taken are same ?

Which of the following compositosn is used as a fertiliser ?

Which one of the following doesn't come under zero group?

What is the mass of an atom ?

Two gases cannot diffuse into each other.

Which of the followingmaterialsfall inthe category of a " Pure Substances" ? (a)Ice (b) Milk ( c) Iron (d) hydrochloricacid ( e)Calcium Oxide ( f)Mercury (g)Bricks (h) Wood (i) Air

Which separation techniques you will apply for the separation of the following mixtures ? (a) Oil from water (b) Camphor from sand (c ) Sodium chloride from its solution in water

Which of the following equilibrium shifts in the backward direction by applying high pressure ?

Turpentine oil when exposed to an atmosphere of chlorine ignites with a black sooty flame. Justify.