Explore topic-wise InterviewSolutions in .

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.

3301.

State the reason for the following behaviour of zinc metal: On placing a piece of zinc metal in a solution of mercuric chloride, it acquires a shining silvery surface but when it is placed in a solution of magnesium sulphate no change is observed.

Answer»

Solution :When a piece of zinc metal is PLACED in a solution of MERCURIC chloride (`HgCl_2`) a white layer of mercury is deposited on zinc metal to give it silvery SHINING LOOK. This is because mercury is lower to zinc is reactivity series and HENCE, zinc can displace mercury from `HgCl_2.`.
But when zinc is placed in a solution of magnesium sulphate, there is no change . This is because magnesium is above zinc in the reactivity series and hence, zinc cannot displace magnesium from its salt solution.
Discussion
3302.

State the reason for conduction of electricity through a solution.

Answer»

SOLUTION : The conduction of ELECTRICITY through a solution is due to the PRESENCE of ions which migrate to opposite ELECTRODES and carry electricity.
Discussion
3303.

State the radius of a hydrogen atom.

Answer»


ANSWER :39 PM
Discussion
3304.

State the proportion of carbon present in the earth's crust and atmosphere.

Answer»

Solution :All the LIVING structures are based on carbon.
The amount of carbon PRESENT in the earth.s crust and in the atmosphere is quite LESS.
The amount of carbon in the earth.s crust is 0.02% in the form of minerals LIKE carbonates, hydrogencarbonates, COAL and petroleum.
The amount of carbon in the atmosphere is 0.03%. It is in the form of carbon dioxide.
Discussion
3305.

State the properties of ionic compounds.

Answer»

Solution :The properties of ionic compounds are as follows:
(1) They have USUALLY high melting points and boiling points.
(2) They possesses STRONG force of ATTRACTION between oppositely charged ions.
(3) They conduct electricity in aqueous solution or in their molten STATE.
( 4 ) They are usually solids.
(5) They are usually soluble in WATER.
Discussion
3306.

State the property utilized in the following : (i) Graphite in making electrodes. (ii) Electric wires are coated with polyvinyl chloride (PVC) or a rubber like material. (iii) Metal alloys are used for making bells and strings of musical instruments.

Answer»

Solution :(i) Graphite is a good conductor of electricity in spite of the REASON that it is a non-metal. It is a crystalline allotropic form of carbon and its ELECTRICAL conductivity is because of the presence of a free ELECTRON in each atom which is available to conduct electricity. (Carbon and its Compounds)
(ii) Electric wires are generally made of metals like copper and aluminium which are good conductors of electricity. In order to INSULATE, these are kept covered with PVC or any other RUBBER like material.
(iii) Gun metal (alloy of Cu = 90 & Sn = 10 parts) is used for making bells because it is very heavy. Similarly, stainless steel or any other variety of steel is used for the manufacture of strings of musical instruments since it is ductile in nature.
Discussion
3307.

State the properties of covalent compounds.

Answer»

Solution :The PROPERTIES of carbon compounds (covalent compounds) are as follows:
(1) They have low melting POINTS and boiling points.
(2) They possesses WEAK force of attraction between the molecules.
(3) They are non-conductors of electricity.
(4) They exist in solid, liquid or GASEOUS states.
(5) They are usually insoluble in water but soluble in organic solvents.
Discussion
3308.

State the properties of carbon compounds.

Answer»

Solution :The properties of carbon compounds (covalent compounds) are as follows:
(1) They have low melting points and boiling points.
(2) They possesses weak force of ATTRACTION between the molecules.
(3) They are non-conductors of electricity.
(4) They exist in SOLID, LIQUID or gaseous states.
(5) They are usually insoluble in WATER but soluble in organic solvents.
Discussion
3309.

State the principle of an electric generator. Write any two differences between electric motors and electric generators.

Answer»

Solution :An ELECTRIC generator WORKS on the principle of electronromagnetic induction when a closed coil is rotated in a uniform MAGNETIC field with its axis perpendicular to the direction of the field. The magnetic field lines passing through the coil changes and induce POTENTIAL differences. Hence a cirrent is SET up in it.
Electric motor
* It converts electrical energy into mechanical energy
* It works on the principle of magnetic field of electric current.
Electric generator
* It converts mechanical energy into electrical energy
* It works on the principle of electromagnetic induction.
Discussion
3310.

State the physical states of non-metals.

Answer»

Solution :Non-metals EXIST in SOLID, liquid and GASEOUS STATES at room temperature.
Discussion
3311.

State the part of the soap molecule that attaches itself to dirt when soap is dissolved in water

Answer»

SOLUTION :It is the Hydropholic END ALSO CALLED TAIL.
Discussion
3312.

State the number of elements present in sixth period of the modern periodic table.

Answer»


ANSWER :32
Discussion
3313.

State the molecular formula and chemical name of iron (III) oxide.

Answer»

Solution :MOLECULAR FORMULA : `Fe_(2)O_(3)`
Chemical name : Ferric OXIDE
Discussion
3314.

State the molecular formula and structural formula of ethanol and ethanoic acid.

Answer»

SOLUTION :
Discussion
3315.

State the Modern Periodic law. Where are metals and nonmetals found in the Modern Periodic Table?

Answer»

Solution :Modern periodic law states that the properties of ELEMENTS are periodic functions of their ATOMIC numbers. In the Modern Periodic Table, metals are FOUND towards the left, non-metals are found towards the RIGHT, and metalloids are found in between metals and non-metals towards the right side.
Discussion
3316.

What is the basis of modern periodic table?

Answer»

Solution :PROPERTIES of ELEMENTS are the PERIODIC FUNCTION of their atomic NUMBER.
(i) There are 18 groups.
(ii) There are 7 periods in the modern periodic table.
Discussion
3317.

State the Modern Periodic law. What is the Modern Periodic Table called?

Answer»

Solution :MODERN PERIODIC law STATES that the properties of elements are periodic functions of their ATOMIC numbers. The Modern Periodic Table is called .long form of the periodic table.
Discussion
3318.

State the merits of Mendeleev's Periodic Table.

Answer»

SOLUTION :(i) Atomic masses of some elements were revised so as to give them proper place in the periodic table in accordance with their properties. For example, the previously determined atomic mass of BERYLLIUM, 14.09, was changed to the correct value 9.4, and beryllium was placed before boron.
(ii)Mendeleev kept vacant spaces in the periodic table for elements not discovered till then. Three fo these unknown elements were given the names eka-boron, eka-aluminium and eka-silicon from the known neighbours and their atomic masses were indicated as 44, 68 and 72 , respectively . Not only this but their properties were also predicted. Later on these elements were discovered and named as scandium (Sc), gallium (Ga) and germanium (Ge) respectively. The properties of these elements matched WELL with those predicted by Mendeleev.
(iii) There was no place reserved for noble gases in Mendeleev.s original periodic table. However, when noble gases such as helium, neon and argon were discovered towards the end of the NINETEENTH century, Mendeleev created the .ZERO. group without disturbing the original periodic table in which the noble gases were fitted very well.
Discussion
3319.

State the meaning of functional group in a carbon compound. Write the functional group present in (i) ethanol, and (ii) ethanoic acid and also draw their structures.

Answer»

Solution :Functional group is an ATOM or a group of ATOMS that is BONDED to a carbon CHAIN. It defines the the chemical property of the organic compound.
Discussion
3320.

State the meaning of functional group an organic compound. Write the formula of the functional group present in alcohols, aldehydes, ketones and carboxylic acids.

Answer»

SOLUTION :Functional group is an atom or a group of atoms that is bonded to a carbon CHAIN. It defines the the chemical property of the ORGANIC COMPOUND.
Discussion
3321.

State the meaning of a functional group in a carbon compound. Write the functional group present in ethanol and ethanoic acid and also draw their structures.

Answer»

Solution :A single atom or a group of atoms that determines the chemical nature of an organic compound is called a FUNCTIONAL group. The functional groups in ETHANOL and ethanoic acid are alcohol and carboxylic acid RESPECTIVELY. Their structures are as follows:
`CH_3-CH_2-OH` ethanol,
`CH_3-overset(O)overset(||)(C)-OH, -OH, -overset(O)overset(||)(C )-O-H` ethanoic acid.
Discussion
3322.

State the main feature that categorises a given pair of organs as homologous or analogous.

Answer»

Solution :The main feature that CATEGORISES a given PAIR of organs as homologous or analogous is:
(i) wether they have same STRUCTURE.
(II) whether they perform same function.
Discussion
3323.

State the main aim of classifying elements. Which is the more fundamental property of elements that is used in the development of Modern Periodic Table ? Name and state the law based on this fundamental property. On which side of the periodic table one can find metals, non-metals and metalloids?

Answer»

SOLUTION :(i) Aim of classification : Systematic study of the known elements.
(ii) Basic PROPERTY : Atomic number.
(iii) Properties of the elements are a periodic function of their atomic numbers.
(iv) METALS on the left.
(v) Non-metals on the right.
(vi) Metalloids at the border of metals and beginning of non-metals.
Discussion
3324.

State the laws of refraction. What is the meaning of the refractive index of crown glass is 1.52. Define the power of lens. What is the meaning of 'The power of a lens is 1 diaptor'. If the power of a lens is -2.0 D, then what type of lens is that? When an object is kept at infinity from this type of lens, what is the size of the image formed?'

Answer»

Solution : Laws of refraction of light are :
The incident ray, the refracted ray and the normal to the interface of two transparent media at the point of incidence, all lie in the same plane.
The ratio of sine of ANGLE of incidence to the sine of angle of refraction is a constant.
`(sin i )/(sin r) ` = constant
This means that the ratio of the speed of light in air and the speed of light in crown glass is equal to 1.52. The ability of a lens to converge or diverge the ray of light after refraction is called POWER (p) of lens. It is defined as the RECIPROCAL of the focal length i.e, `P = 1/f`
S.I unit of power of a lens is dipotre. A lens of focal length 100 em has a power of 1 dipotre i.e, 1 dioptre =`1m^(-1) `If the power of a lens is -2.0 D then the type of lens is concave lens. The SIZE of the image in the lens is highly diminshed, point SIZED.
Discussion
3325.

State the law which governs a balanced chemical equation .

Answer»

Solution :The law of CONSERVATION of mass GOVERNS a balanced chemicalequation. It say : The TOTAL mass of reactants is EQUAL to the total mass of PRODUCTS during a chemical reaction.
Discussion
3326.

State the law of conservation of energy.

Answer»

SOLUTION :Matter can NEITHER be CREATED nor be DESTROYED. (or Energy can neither be created nor be destroyed but can be converted from one form to another).
Discussion
3327.

State the law is followed in balancing chemical equation.

Answer»

Solution :MASS can NEITHER be CREATED nor be DESTROYED in a chemical reaction. It s the law of conservation of mass.
Discussion
3328.

State the kind of chemical reactions in the following examples: (i) Digestion of food in stomach (ii) Combustion of coal in air (iii) Heating of limestone.

Answer»

Solution :(i) DECOMPOSITION REACTION and Exothermic reaction
`C_(6)H_(12)O_(6)+6O_(2)rarr6CO_(2)+6H_(2)O+`Energy
(ii) COMBINATION reaction
`C+CO_(2)rarrCO_(2)`
(iii) Decomposition reaction
`CaCO_(3)(S) overset ("Heat")rarrCaO(S)+CO_(2)(g)`
Discussion
3329.

State the importance of balanced chemical equation.

Answer»

Solution :The importance of balanced chemical equation are as follows:
(1) Number of moles of the reactants and PRODUCTS INVOLVED in the reaction can be known by the balanced chemical equation.
(2) Balanced chemical equation gives details about the QUANTITY of reactant used and quantity of products formed during chemical reaction.
(3) Physical state of the reactants and products can be known.
Discussion
3330.

State the general properties of ionic compounds.

Answer»

Solution : The general (common) properties of ionic compounds are as FOLLOWS: (1) Physical nature : The ionic compounds are solids and hard because of the strong forces of ATTRACTION between the positive and negative ions. These compounds are generally BRITTLE and break into picccs when pressure is applied. (2) MELTING and BOILING points: A considerable large amount of energy is required to break the strong inter ionic attraction . Hence ionic compounds have high melting and boiling points . For example,

(3) Solubility : Electrovalent (Ionic) compounds are generally soluble in polar solvent like water and insoluble in non-polar organic solvents such as kerosene, petrol, etc. (4) Conduction of electricity : The conduction of electricity through a solution involves the movement of charged particles. A solution of an ionic compound in water contains ions, which move to the opposite electrodes, when electricity is passed through the solution. Ionic compounds in the solid state do not conduct electricity because the movement of ions in the solid is not possible due to their rigid structure. But, ionic compounds conduct electricity in the molten state. Since the electrostatic forces of attraction between the oppositely charged ions are overcome and free ions are obtained due to heat. As a result, these ions move freely and conduct electricity.
Discussion
3331.

State the general formula of unsaturated alkene compounds.

Answer»

SOLUTION :`C_(N)H_(2N)`
Discussion
3332.

State the general formula of saturated alkane compounds.

Answer»

SOLUTION :`C_(N)H_(2n+2)`
Discussion
3333.

State the general formula of carboxylic acids.

Answer»

SOLUTION :`C_(N)H_(2n+1) COOH`.
Discussion
3334.

State the full form of PVC.

Answer»

SOLUTION :The FULL FORM of PVC : PolyVinyl CHLORIDE
Discussion
3335.

State the formation of magnesium chloride by the transfer of electrons.

Answer»

Solution :ATOMIC number of MAGNESIUM is 12. It loses its two electrons from outermost shell and acquires COMPLETE octet stable structure.
`underset(2,8,2)(Mg) to underset(2,8)(Mg^(2+))+ 2e^-`
Similarly, atomic number of chlorine is 17. It gains one electron and acquires complete octet stable structure.
`underset(2,8,7)(CL + e^-) to underset(2,8,8)(Cl^-)`
Thus, two electrons LOST by magnesium atom are gained by two chlorine atoms (each one gets one electron) and forms magnesium chloride.
Discussion
3336.

State the following: How does metallic character change in a period on moving from left to right?

Answer»

SOLUTION :DECREASES
Discussion
3337.

State the following: How do the atomic radii change in a period with increasing atomic number?

Answer»

SOLUTION :DECREASE
Discussion
3338.

State the exceptions of metallic and non metallic elements.

Answer»

Solution : Exceptions of metallic elements :
( 1 ) All metals except MERCURY are solids at room temperature, while mercury is a liquid at room temperature. (2) Generally, metals have high melting points but Galium and Caesium have very low melting points. (3 ) Alkali metals (Lithium, sodium, potassium) are very soft hence, they can be cut with a KNIFE, while other metals cannot be cut with a knife.
Exceptions of non-metallic elements :
(1) Generally, non-metals exist as solids or gases at room temperature while BROMINE is a liquid (2) Non-metals does not possess lustre, but iodine is the only non-metal which POSSESSES lustre. (3) Non-metals have low melting points, but the diamond, an allotrope of carbon possesses very high melting point. (4) Non-metals are generally non-conductors of electricity, but the graphite, an allotrope of carbon is the only non-metal which conducts electric current.
Discussion
3339.

State the example of the combination reaction that is also exothermic by nature. How will you show its exothermic nature in the laboratory ?

Answer»

Solution :REACTION of quick lime (calcium oxide) with WATER is highly exothermic and liberates more heat which can be MEASURED by a thermometer in the LABORATORY.
Discussion
3340.

State the equations of zinc and lead, where it displaces copper from its compounds.

Answer»

Solution :`ZN(s)+ underset("Copper sulphate")(CuSO_(4)(aq)) to underset("ZINC sulphate")(ZnSO_(4)(aq)) +Cu(s)`
`PB(s) + underset("Copper chloride")(CuCl_(2)) to underset("Lead chloride")(PbCl_(2)) +Cu(s)`
Discussion
3341.

State the elements used as catalyst in hydrogenation reaction.

Answer»

SOLUTION :NICKEL, PALLADIUM
Discussion
3342.

State the common properties of nonmetallic elements.

Answer»

Solution : The common properties of non-metallic elements are as follows:
( 1 ) Non-metallic elements exists either solids or gases at the ROOM temperature. (EXCEPTION : Bromine, it is a liquid.) (2) They are non-conductors of heat and electricity (3) They do not possess malleability and DUCTILITY. (4) They have lower melting points and boiling points in comparison to metals. (5) They are non-sonorous.
Discussion
3343.

State the common properties of non-metals based on the above activities.

Answer»

SOLUTION :(1) Non-metals are non-conductors of HEAT and electricity. (2) Boiling POINTS of non-metals are comparatively LOWER. ( 3 ) Non-metals do not possess property of malleability and ductility.
Discussion
3344.

state the condition in which a sample of silver chloride gets decomposed to form silver.

Answer»

Solution :Silver chloride gets decomposed to form silverwhen it is left exposed to SUNLIGHT .
` 2AgCI overset(hv)to underset("silver")(2AG) +CI_(2)`
Discussion
3345.

State the chemical reactions observed in daily life.

Answer»

Solution :Chemical reactions observed in daily life are as follows:
(1) Milk get spoiled at room temperature during summer.
(2) Iron ARTICLES such as an iron pan, nail when EXPOSED to HUMID AIR get corroded.
(3) Fermentation of grapes.
(4) Cooking of food.
(5) Digestion of food in the body.
( 6 ) In the process of respiration.
Discussion
3346.

State the chemical name of plaster of paris . Write a chemical equation to show the reaction between plaster of paris and water.

Answer»

Solution :`CaSO_4.1/2 H_2O` (calcium sulphate HEMIHYDRATE)
When plaster of paris reacts with WATER GYPSUM is formed.
`CaSO_4. 1/2H_2O+1 1/2H_2Oto CaSO_4. 2H_2O`
(Plaster of paris) (Gypsum)
Discussion
3347.

State the chemical properties on which the following uses of baking soda are based. (i) as an antacid (ii) as soda-acid fire extinguisher (iii) To make bread and cake soft and spongy

Answer»

Solution :(i) It is weakly basic in nature and neutralises hyper acidity.
(ii) It LIBERATES `CO_(2)` with `H_(2)SO_(4)` which extinguishes fire.
(iii) It liberates `CO_(2)` on HEATING which passes through dough and makes bread and CAKE soft and spongy.
Discussion
3348.

State the ascending order of reactivity for Cu, Ag and Fe metals based on the reaction given below: (i) Fe(s)+ CuSO_(4) to FeSO_(4)(aq)+Cu(s) (ii) Cu(s)+ FeSO_(4)(aq) to "No reaction" (iii) Cu(s) +2AgNO_(3)(aq) to Cu(NO_(3))_(2)(aq)+2Ag(s)(iv) 2Ag(s)+Cu(NO_(3))_(2) to "No reaction"

Answer»

SOLUTION : Based on the given REACTION, ascending order of REACTIVITY of CU, Ag and Fe is as follows:
`Ag LT Cu lt Fe`
Discussion
3349.

State reasons for the following: Sulphide ore of a metal is first converted to its oxide to extract the metal from it.

Answer»

SOLUTION :It is because it is easier to REDUCE oxide ORE as COMPARED to sulphide ore.
Discussion
3350.

State reasons for the following:(i) Metals are good conductors of heat. (ii) Addition of some silver to pure gold for making ornaments.(iii) Inability of non-metals for displacing hydrogen from dilute sulphuric acid.

Answer»

Solution :(i) METALS possess free or mobile electrons which are responsible for conduction of heat.(II) Addition of some silver to pure gold makes it hard which is necessary for making ORNAMENTS. (iii) Non-metal cannot provide electrons to convert `H^+`ions to HYDROGEN gas.
Discussion