8881 + Interview Questions in Chemistry in Class 10 Page 47 InterviewSolution

2301.	The standardpressureis ______.
Answer» SOLUTION :`1.00 ` ATM

Discussion

2302.	Think about it, What is the relationship between the electronic configuration of an element and its valency?
Answer» Solution :Electronic configuration MEANS the arrangementof electrons in their respective shells INCLUDING valence SHELL. The number of electrons in the valence shell DETERMINES its VALENCY. Thus, electronic configuration in a way determines the valency of an element.

Discussion

2303.	When ammonia gas is subjected to sudden expansion from a region of high pressure into a region of low pressure, which of the following changes is expected to take place?
Answer» DECREASE in KINETIC ENERGY and POTENTIAL energy conversion ofkinetic energy topotential energy conversion of potential energy to kinetic energy increase in kinetic energy and potential energy Answer :B

Discussion

2304.	Which fundamental particle forms the real basis for the modern classification of elements ?
Answer» Proton Electron Neutron Nucleon

Discussion

2305.	You havetwo solutions, A and B. The pH of solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration ? Which of this is acidic and which one is basic ?
Answer» Solution :SUBSTANCES with a pH between 1 and 7 are ACIDS and 7-14 are bases. As pH of solution A is lower than 7, it is an acid while 8 is basic as its pH is greater than 7.

Discussion

2306.	Write thebalanced chemical equation for the reaction between sodium carbonate and hydrochlorc acid indicating the physical states of reactants and products.
Answer» Solution :BALANCED chemical equation is `Na_(2)CO_(3)(s) + 2HCl(aq)RARR 2NaCl(aq) + CO_(2)(g) + H_(2)O(L)`

Discussion

2307.	What is meant by skeletal equation ? Give an example.
Answer» SOLUTION :EQUATION in which chemical formulae of the substances are represented briefly is CALLED skeletal equation. In skeletal equation, the REACTION is not balanced and the mass is not the same on both sides of equation. For example, `Mg + O_(2) to MGO`

Discussion

2308.	The valence electrons of an element are responsible for
Answer» PHYSICAL PROPERTIES of an ELEMENT chemical properties of an element both the properties none of these Answer :B

Discussion

2309.	Which among the following are physical or chemical changes? (a) Evaporation of petrol (b) Burning of Liquefied Petroleum Gas (LPG) (c ) Heating of an iron rod to red hot (d) Curdling of milk (e) Sublimation of solid ammonium chloride
Answer» Solution :(a) PHYSICAL CHANGE (B) CHEMICAL change (c ) Physical change (d) Chemical change (e) Physical change

Discussion

2310.	Which of the following is not an oxidising agent
Answer» oxygen CONC sulphuric acid CHLORINE HYDROGEN SOLUTION :conc sulphuric acid

Discussion

2311.	When ethanol vapour is passed through bromine water . Why does no changeoccur ?
Answer» Solution :As ETHANOL BELONG to the GROUP of saturatedhydrocarbons , it does not change itscolourwhen passed through bromine WATER .

Discussion

2312.	Write the name and structural formula of the compound formed when ethanol is heated at 443K temperature with excess of conc. H_(2)SO_(4). What is the role of conc. H_(2)SO_(4) in this reaction ? Also give the chemical equation for the reaction.
Answer» Solution :The NAME of the compound formed is Ethene and its structural FORMULA is `underset"ETHANOL"(CH_(3)CH_(2))OHoverset(conc.H_(2)SO_(4))underset "443K"rightarrow underset"Ethene"(CH_(2))=CH_(2)+H_(2)O` Role of `H_(2)SO_(4)`: It work asla catalyst to INITIATE the reaction to LOSE watermolecule to form alkene.

Discussion

2313.	Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous CuSO_(4) and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is (are) correct ? (i) Inbeakers A and B, exothermic process has occurred. (ii) In beakers A and B, endothermic process has occurred. (iii) In beaker C exothermic process has occurred. (iv) In beaker C endothermic process has occurred.
Answer» (i) only (ii) only (i) and (IV) (ii) and (iii) Solution :Increase of TEMPERATURE means EXOTHERMIC PROCESS and FALL of temperature means endothermic process.

Discussion

2314.	Write the equation for the reaction of (I) iron with steam (II) Calcium and Potassium with water.
Answer» Solution :(I) `3Fe+4H_(2)Ooverset(Delta)(hArr)Fe_(3)O_(4)+4H_(2)` (II) `Ca+2H_(2)OtoCa(OH)_(2)+H_(2)` , `2K+2H_(2)Oto2KOH+H_(2)`

Discussion

2315.	Which of the following statements is correct regarding the colloid of starch in water ?
Answer» It can be separated by filtration It is transparent and unstable It shows TYNDALL effect It s PARTICLES are visible to the naked eye ANSWER :A,C

Discussion

2316.	What similarity do you find in their electronic configurations of Li , Na , K ?
Answer» Solution :All the three elements have one ELECTRON in their OUTERMOST shell, i.e., they have one VALENCE electron .

Discussion

2317.	Which of the following represent alkynes?
Answer» `-C-C-` `-C=C-` `-C-=C-` NONE of these Answer :C

Discussion

2318.	Write the general formula of alcohols and prepare a homologous series of alcohols containing up to 5 carbon atoms.
Answer» Solution :GENERAL formula of alcohols : `C_nH_(2n+1) OH` Homologous SERIES: `(i) CH_3OH (ii) C_2H_5OH (III) C_3H_7OH (IV) C_4H_9OH (v) C_5H_11OH `

Discussion

2319.	Which one gives a red precipitate with ammoniacal solution of copper(I) chloride? (A) Ethane (B) Ethene (C) Ethyne (D) Propane
Answer» Ethane Ethene ETHYNE PROPANE ANSWER :C

Discussion

2320.	The relative atomic masses of many elements are not whole numbers because
Answer» they can’t be DETERMINED very ACCURATELY the atoms ionize during the determinatio of the EXISTENCE of ISOTOPES of the presence of impurities Answer :C

Discussion

2321.	Which order of relative size amongst the following is incorrec ?
Answer» `LI LT Na lt K` `O lt N lt F` `AI lt MG lt Na` `F lt CI lt Br` Answer :B

Discussion

2322.	Which of the following salts does not contain water of crystallisation ?
Answer» BLUE vitriol BAKING SODA Washing soda Gypsum Solution :Baking soda

Discussion

2323.	Write the names of two salts belonging to sodium family.
Answer» SOLUTION :1. Sodium CARBONATE 2. Sodium HYDROGENCARBONATE.

Discussion

2324.	Which functional group is to be given suffixol in the nomenclature ?
Answer» `-CHO` `{:("\"),("/"):}C=O` `-OH` `-X` ANSWER :C

Discussion

2325.	Which of the following is not a base?
Answer» `KOH` `Ca(OH)_(2)` `K_(2)SO_(4)` `ZNO` Solution :NA

Discussion

2326.	which of the following is a displacement reaction ?
Answer» `CaCO_(3) to CAO + CO_(2)` `CaO + 2HCI to CaCl_(2) +H_(2)O` `Fe + CuSO_(4) to FeSO_(4) + Cu` `NaOH + HCI to NACI + H_(2)O` Answer :C

Discussion

2327.	Write the functions of Forebrain, Medulla and Cerebellum in human brain.
Answer» Solution :Fore brain : It is the MAJOR thinking part of the brain. It has regions to receive sensory IMPULSES from various RECEPTORS, for hearing, smell sight and so on. Decision made is sent to the motor areas which send messages to the effector organ muscles to respond Cerebellum : Precision of voluntary actions such as walking in a straight line, riding a bicycle, PICKING up a pencil are possible because of cerebellum. It ALSO help in maintaining the posture and balance of the body. Medulla : Involuntary actions such as maintaining blood pressure, salivation and vomiting.

Discussion

2328.	While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid ?
Answer» Solution : The process of dissolving an ACID or a base in water is an exothermic process. This is because if water is added to concentrated acid, the heat generated may cause the MIXTURE to splash out and cause burns. The glass container may also break due to excessive local HEATING.

Discussion

2329.	Volume percentage decreases with increases in temperature because………
Answer» SOLUTION :EXPANSION of LIQUID

Discussion

2330.	Two solutions X and Y have pH values of 3.0 and 9.5 respectivelywhich of these will turn litmus solution from blue to red and which will turn phenolphthalein from colourless to pink ?
Answer» Solution :X will turn blue LITMUS to red because it is acidic in NATURE having pH value less than 7. Y will turn phenolphthalein from colourless to PINK because it is basic in nature having pH value greater than 7.

Discussion

2331.	Which of the following salt gets hydrolyzed in aqueous solution? A salt of
Answer» WEAK ACID and weak base STRONG acid and weak base weak acid and strong base all of these Answer :D

Discussion

2332.	Think about it, What is the periodic trend in the variation of valency while going down a group? Explain the answer with reference to group 1, group 2 and group 18.
Answer» Solution :(i) 1 A 1 the elements in a group have the same NUMBER of electrons in the OUTERMOST shell. Therefore,down the grorp, VALENCY remains the same. (ii) Valency of group 1 elements is 1 and that of group 2 elements is 2. (III) Th e valency of group 18 elements is zero because they are noble gases with COMPLETED outermost shell.

Discussion

2333.	Write the essential condition for the following reaction to take place : 2AgBrto2Ag+Br_(2)
Answer» Solution :`2AgBroverset("SUNLIGHT")(to)2Ag+Br_(2)` The consition is that sunlight is essential to DECOMPOSE SILVER bromide into silver and bromine.

Discussion

2334.	Which of the following is a plant hormone?
Answer» THYROXIN Cytokinin Insulin Oestrogen Answer :B

Discussion

2335.	XeF_(2) and ICl_(2)^(–) are iso structural.
Answer» ANSWER :TRUE

Discussion

2336.	We can judge how strong an acid or base is by making use of ________
Answer» SOLUTION :UNIVERSAL INDICATORS.

Discussion

2337.	What is a neutrilisation reaction ? Give two examples.
Answer» Solution :The intraction of an ACID with a BASE to form salt and WATER is called NEUTRALISATION reaction. Examples : `HCl + NaOH to NaCl + H_2O ` `HNO_3 + KOH to KNO_3 + H_2O`

Discussion

2338.	The symbol of Tin is
Answer» SN Pb An Br Solution :Sn

Discussion

2339.	The second member of alkyne family is
Answer» `CH_4` `C_2H_4` `C_2H_2` `C_3H_4` ANSWER :D

Discussion

2340.	Which out of the following is a homogeneous mixture?
Answer» milk STEEL smoke soil SOLUTION :steel

Discussion

2341.	What is an homologous series ? Explain with an example.
Answer» Solution :SERIES of compounds in which the same functional group substitutes for hydrogen in a carbon chain is called a homologous series. `CH_(3)OH,C_(2)H_(5)OHandC_(3)H_(7)OH` is an example of homologous series. The difference between the formulae of any two SUCCESSIVE members is- `CH_(2)` while the difference between the molecular masses is 14 u.

Discussion

2342.	The vacant space in unit cells is in the order of
Answer» SIMPLE CUBIC gt body centredgt Face CENTRED Face Centred gt simple cubic gt body centred body centred gt Face Centred gt simple cubic None of the above Answer :A

Discussion

2343.	Which of the following is not an example of combination reaction ?
Answer» `2H_(2)(G)+O_(2)(g)to2H_(2)O(l)` `AgNO_(3)+NaCl(aq)toAgCl(s)+NaNO_(3)(aq)` `C(s)+O_(2)(g)toCO_(2)(g)` `CH_(4)(g)+2O_(2)(g)toCO_(2)(g)+2H_(2)O(g)` Solution :This is an example of couble displacement reaction `AgNO_(3)+NaCl to AGCL(s)+NaNO_(3)`

Discussion

2344.	There are three elements X, Y and Z having atomic numbers of 6, 16 and 19 respectively. Based on this information, Het has been asked to answer the following questions: What values are displayed by Het in answering the above questions?
Answer» Solution :In ORDER to ANSWER these questions, Het first wrote down the electronic configurations of the elements X, Y and Z by using their ATOMIC numbers, as follows: (6) The VALUES displayed by Het in answering these questions are (1) knowledge of modern classification of elements, and (2) understanding of periodic table.

Discussion

2345.	Which of the following are present in dilute aqueous solution of hydrochloric acid ?
Answer» `H_(3)O^(+) + Cl^(-)` `H_(3)O^(+) + OH^(-)` `Cl^(-) + OH^(-)` UNIONISED HCl Solution :`H_(3)O^(+) + Cl^(-)`

Discussion

2346.	Which of the following elements will gain one electron more readily in comparison to other elements of their group?
Answer» Mg Na O Cl Solution :Cl gain ONE ELECTRON most readily because Cl is short of just one electro to attain nearest NOBLE gas CONFIGURATION.

Discussion

2347.	What is an amphoteric oxide ?
Answer» Solution : METAL oxide which REACTS with both acid as well as base to produce salt and WATER is known as an AMPHOTERIC oxide.

Discussion

2348.	What is homologous series of carbon compounds ? List its any two characteristics. Write the name and formula of next higher homologue of HCOOH.
Answer» Solution :A series of compounds whose two successive members differ by `-CH_(2)` in the molecule formula and which show SIMILAR chemical properties are CALLED homologous series. Characteristics : 1. Melting and boiling points increase regularly with increase in molecular mass. 2. Solubility in a particular solvent SHOWS a regular gradation. 3. Chemical properties remain the same in the homologous series. Next higher homologue of HCOOH is `CH_(3)COOH`. Its name is ethanoic acid or acetic acid.

Discussion

2349.	Write the balanced chemical equation for each of the following. On heating copper powder in a china dish the surface of the copper becomes black.
Answer» SOLUTION :`2Cu(s)+O_(2)(G)OVERSET(Delta)(to)2CuO(s)`.

Discussion

2350.	What is the practical application of the electrolysis of copper sulphate solution ?
Answer» SOLUTION :It is EMPLOYED in the electroyed in the electrolytic REFINING of BLISTER copper .

Discussion

Explore topic-wise InterviewSolutions in .

The standardpressureis ______.

Think about it, What is the relationship between the electronic configuration of an element and its valency?

When ammonia gas is subjected to sudden expansion from a region of high pressure into a region of low pressure, which of the following changes is expected to take place?

Which fundamental particle forms the real basis for the modern classification of elements ?

You havetwo solutions, A and B. The pH of solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration ? Which of this is acidic and which one is basic ?

Write thebalanced chemical equation for the reaction between sodium carbonate and hydrochlorc acid indicating the physical states of reactants and products.

What is meant by skeletal equation ? Give an example.

The valence electrons of an element are respon­sible for

Which among the following are physical or chemical changes? (a) Evaporation of petrol (b) Burning of Liquefied Petroleum Gas (LPG) (c ) Heating of an iron rod to red hot (d) Curdling of milk (e) Sublimation of solid ammonium chloride

Which of the following is not an oxidising agent

When ethanol vapour is passed through bromine water . Why does no changeoccur ?

Write the name and structural formula of the compound formed when ethanol is heated at 443K temperature with excess of conc. H_(2)SO_(4). What is the role of conc. H_(2)SO_(4) in this reaction ? Also give the chemical equation for the reaction.

Write the equation for the reaction of (I) iron with steam (II) Calcium and Potassium with water.

Which of the following statements is correct regarding the colloid of starch in water ?

What similarity do you find in their electronic configurations of Li , Na , K ?

Which of the following represent alkynes?

Write the general formula of alcohols and prepare a homologous series of alcohols containing up to 5 carbon atoms.

Which one gives a red precipitate with ammoniacal solution of copper(I) chloride? (A) Ethane (B) Ethene (C) Ethyne (D) Propane

The relative atomic masses of many elements are not whole numbers because

Which order of relative size amongst the following is incorrec ?

Which of the following salts does not contain water of crystallisation ?

Write the names of two salts belonging to sodium family.

Which functional group is to be given suffixol in the nomenclature ?

Which of the following is not a base?

which of the following is a displacement reaction ?

Write the functions of Forebrain, Medulla and Cerebellum in human brain.

While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid ?

Volume percentage decreases with increases in temperature because………

Two solutions X and Y have pH values of 3.0 and 9.5 respectivelywhich of these will turn litmus solution from blue to red and which will turn phenolphthalein from colourless to pink ?

Which of the following salt gets hydrolyzed in aqueous solution? A salt of

Think about it, What is the periodic trend in the variation of valency while going down a group? Explain the answer with reference to group 1, group 2 and group 18.

Write the essential condition for the following reaction to take place : 2AgBrto2Ag+Br_(2)

Which of the following is a plant hormone?

XeF_(2) and ICl_(2)^(–) are iso structural.

We can judge how strong an acid or base is by making use of ________

What is a neutrilisation reaction ? Give two examples.

The symbol of Tin is

The second member of alkyne family is

Which out of the following is a homogeneous mixture?

What is an homologous series ? Explain with an example.

The vacant space in unit cells is in the order of

Which of the following is not an example of combination reaction ?

There are three elements X, Y and Z having atomic numbers of 6, 16 and 19 respectively. Based on this information, Het has been asked to answer the following questions: What values are displayed by Het in answering the above questions?

Which of the following are present in dilute aqueous solution of hydrochloric acid ?

Which of the following elements will gain one electron more readily in comparison to other elements of their group?

What is an amphoteric oxide ?

What is homologous series of carbon compounds ? List its any two characteristics. Write the name and formula of next higher homologue of HCOOH.

Write the balanced chemical equation for each of the following. On heating copper powder in a china dish the surface of the copper becomes black.

What is the practical application of the electrolysis of copper sulphate solution ?

The valence electrons of an element are responsible for