8881 + Interview Questions in Chemistry in Class 10 Page 65 InterviewSolution

3201.	The acidity and alkalinity of a compound is represented on a scale known as
Answer» PH SCALE Hess scale Kelvin Scale NONE of these Solution :pH scale

Discussion

3202.	The acid produced in our stomach is :
Answer» LACTIC ACID Oxalic Acid HYDROCHLORIC Acid Methanoic Acid Solution : Hydrochloric Acid

Discussion

3203.	The acid present in orange juice is citric acid.
Answer» ANSWER :T

Discussion

3204.	The absolute charge on the electron is.
Answer» `1.1 xx 10^(11)` C `1.6xx 10^(14)`C `1.6xx10^(-19)` C `6.0 xx 10^(21)` C Answer :C

Discussion

3205.	The ability of the metals to be drawn into thin wires is known as
Answer» ductility malleability sonorousity conductivity Solution :The ABILITY of a METAL to be DRAWN into WIRES is CALLED ductility.

Discussion

3206.	The ability of carbon atom to link with other carbon atom is known as_____.
Answer» SOLUTION :CATENATION

Discussion

3207.	The3 elements which were predicted byMendeleev for which he left blank spaces in theperiodic table.
Answer» SOLUTION :Eka-Boron, Eka-Silicon, Eka-Aluminium.

Discussion

3208.	The 18th group of elements in the periodic table is called
Answer» ALKALI metals alkaline earth-metals HALOGENS NOBLE gases Answer :D

Discussion

3209.	Thallous compounds are more common and stable than thallic compounds. Justify this statement.
Answer» SOLUTION :(i)valence electronic configuration of thallium (II) comparison of the EASE of formation of thallous and thallic ions (iv) relation between the ease of formation of ion and availability of the compound in NATURE CONTAINING that ion

Discussion

3210.	TFM in soaps represents………………….content in soap.
Answer» SOLUTION :TFM - Total FATTY Matter. It corresponds the fatty ACID (oil)

Discussion

3211.	Tell whether heat is evolved or absorbed when quick lime is added to water.
Answer» SOLUTION :HEAT is EVOLVED.

Discussion

3212.	Tellurium :_________ :: Radium : Metal
Answer» SOLUTION :METALLOID - Tellurium has PROPERTIES of both METALSAND non metals, therefore, it is called a metalloid.

Discussion

3213.	Tell me Why cannot a chemical change be normally reversed?
Answer» Solution :In a chemical change, some bonds are BROKEN and some bonds are FORMED. The products are quite different from the reactants. THEREFORE -it normally cannot be REVERSED.

Discussion

3214.	Tell me Why is it always essential tobalance a chemical equation?
Answer» SOLUTION :A chemical EQUATON has to be BALANCED to satisfy the law of CONSERVATION of MASS

Discussion

3215.	Tell me Can rusting of iron take place in distilled water?
Answer» Solution :No, rusting of iron cannot take PLACE in distilled WATER because it NEITHER contains. dissolved OXYGEN nor `CO_2` both of which are essential for the rusting of iron.

Discussion

3216.	Tell me What happens when carbon dioxide gas is passed through lime water and why does it disappear on passing excess carbon dioxide?
Answer» Solution :On passing `CO_2` gas through lime WATER, it turns milk due to formation of insoluble calcium carbonate WHICT dissolves on passing excess `CO_2` due to the formation of soluble calcium bicarbonate. `CA)OH)_2+CO_2(----toCaCO_3(s)+H_2O(l)` `CaCO_3(s)+H_2O(l)+CO_2(g)------TOCA(HCO_3)_2` (soluble)

Discussion

3217.	Teacher explained periodictiy of ionisation potential in a period and group with reasons. She then drew a curve of IP vs. atomic numeber for elements with Z = 11 to Z = 20.On the basis of the curve, she asked the following questions to students. (a) Identify the elements occupying peaks and bottom-most points.(b) Also identify 'X', and 'Y' marked in the curve. (c) In what respect 'X' and 'Y' deviat from their preceeding elements? ltbegt When students answered these correctly, she was satisfied and told - "Now, I will give you a brain teaser to get me answer by next chemistry class" . Students enthusiastically said - "yes"! Then teacher wrote the following question on board __ (d)" Why do "X" and "Y" show deviations from their preceeding elements in the trend of IP velues"? What explanation would you give if you were there in the class?
Answer» Solution :(a) Peak is occupied by noble gas, Ar. Bottom-most point is occupied by alkali metal, K. (b) 'X' is aluminium and 'Y' is sulphur. (c) Generally, with increase in atomic number, IP value should also increase. However, from MAGNESIUM to aluminium, IP value decreases. Similariy, from PHOSPHORUS to sulphur, IP value decreases. (d) In magnesium, there is a pair of electrons in 3s orbital. REMOVAL of electron is slightly more difficult. Morepver, since the electron to be removed belongs to 's' subshell having greater penetrating power, the IP value is relatively HIGHER. In case of aluminium, there is an unpaired 'p' electron, whose removal is easier. Hence, IP value is less.

Discussion

3218.	Tartaric acid is present in :
Answer» Orange Tomato TAMARIND Sour milk. Solution :Tamarind

Discussion

3219.	Tap water is
Answer» COMPOUND a MIXTURE an ELEMENT NONE of these SOLUTION :a mixture

Discussion

3220.	Taking the example of an element of atomic number 16, explain how the electronic configuration of the atom of an element relates to its position in the Modern Periodic Table and how valency of an element is calculated on the basis of its atomic number.
Answer» Solution :In the Modern PERIODIC Table, the number of electron shells present in the atom of an element gives its PERIOD number while the number of valence electrons decides its GROUP number. For example, element of atomic number 16 has the electronic configuration 2, 8, 6. SINCE it has 3 electron shells, it is PLACED in the 3rd period and since it has 6 valence electrons, it is placed in 10+6 = 16th group. Since the element needs 2 more electrons to attain a noble gas configuration, its valency is 2.

Discussion

3221.	Taking the example of an element of atomic number 16, explain how the electronic configurationof the atom of an element relates to its position in the Modern Periodic Table and how valency of an element is calculated on the basis of its atomic number.
Answer» Solution :ATOMIC number of the element = 16 Electronic configuration = 2, 8,6 Period number = Number of SHELLS The atom of the element has three shells. So, the period number is 3. The atom of the element has SIX valence electrons. So, the group number of the element will be 16 (6 + 10). Valency = 8 – number of valence electrons (> 5) or number of valence electrons (< 5)

Discussion

3222.	Take two conical flasks.Label them as I and II .Take a small amount of copper sulphate solution in the first conical flask.Take a small amount of granulated zinc in the second conical flask.Allow the copper sulphate solution to react with the zinc. (i)Name the type of reaction. (ii)Say whether the metal zinc is more reactive or less reactive. (iii)Write the complete and balanced reaction. (iv)Say whether this change is reversible or irreversible.
Answer» Solution :(i)The reaction taken place is displacement reaction. Metal zinc is more REACTIVE . (iii)Balanced chemical equation. `Zn_((s))+CuSO_(4(AQ))toZnSO_(4(aq))+Cu_((s))darr` (iv)This CHANGE is an irreversible change.

Discussion

3223.	takesome carboncompounds( naphthalene, camphor, alcohol) onebyoneona spatulaand burnthem observethe natureof theflameand notewhethersmokeis produced placea metalplateabovetheflame. Istherea depositionon theplatein caseof anyof thecompounds?
Answer» SOLUTION :alcoholburns a blueflamewithoutleavinganyresiduenaphthaleneburnwitha yellowsooctyflame

Discussion

3224.	Take copper nitrate in a test tube heat it over the flame. (i)What is the colour of cupric nitrate ? (ii)What do you observe ? (iii)Name the type of reaction that takes place. (iv)Write the balanced equation.
Answer» SOLUTION :(i)The COLOUR of cupric NITRATE is blue. (II)When cupric nitrate is heated in a test tube,we can observe the evolution of reddish brown GAS `(NO_(2))` Nitrogen di-oxide. (iii)The reaction takes place is decomposition reaction. `underset("Cupric nitrate")(2Cu(NO_(3))_(2))overset(Delta)tounderset("Cuprix oxide")(2CuO)+underset("Nitrogen di-oxide")(4NO_(2)uarr+O_(2)uarr)`

Discussion

3225.	Take 3 g of barium hydroxide in a test tube, now add about 2 g ammonium chloride and mix the contents with the help of a glass rod. Now touch the test tube from outside. Write the balanced chemical equation of the reaction involved.
Answer» SOLUTION :`2NH_(2)Cl+Ba(OH)_(2)toBaCl_(2)+2NH_(3)uarr+2H_(2)O`

Discussion

3226.	Take 3 g of barium hydroxide in a test tube, now add about 2 g ammonium chloride and mix the contents with the help of a glass rod. Now touch the test tube from outside. State the inference about the type or reaction occurred.
Answer» SOLUTION :It is a decompotition REACTION.

Discussion

3227.	Take 3 g of barium hydroxide in a test tube, now add about 2 g ammonium chloride and mix the contents with the help of a glass rod. Now touch the test tube from outside. What do you feel on touching the test tube ?
Answer» SOLUTION :The TEST TUBE BECOMES HOT.

Discussion

3228.	Take10 gofcommonsalt anddissolveit in40gof water. Findtheconcentrationof solutionin termsof weightpercent .
Answer» Solution :Weightpercent=`("WEIGHT of the solute")/("Weightof solute + weightof SOLVENT") xx 100` `= ( 10) /( 10 +40 ) xx 100= 20 %`

Discussion

3229.	Switching off lights and fans when not in use can save
Answer» WIND ENERGY electricity heat energy NONE of these ANSWER :B

Discussion

3230.	Suspension of slaked lime in water in known as
Answer» LIME water quick lime milk of lime aqueous SOLUTION of SLAKED lime Answer :A

Discussion

3231.	Surface of metals loses their brightness when kept in air for a long time. Why ?
Answer» Solution :Metals REACT with OXYGEN and moisture in air, forming a LAYER of metal OXIDE on the SURFACE of the metal.

Discussion

3232.	Surekha was very upset as her silver jewellary had turned black, and lost its lustre. Her father is a science teacher and he washed and cleaned the jewellary using toothpaste and brought the shine back. What value of Surekha.s father is seen in this act ?
Answer» Solution :Surekha.s FATHER showed the VALUE of responsible BEHAVIOUR and TEACHING art.

Discussion

3233.	Surekha was very upset as her silver jewellary had turned black, and lost its lustre. Her father is a science teacher and he washed and cleaned the jewellary using toothpaste and brought the shine back. How had the toothpaste got the shine of silver back ?
Answer» Solution : Toothpaste reacts with black coating of SILVER SULPHIDE and REMOVES it.

Discussion

3234.	Surekha was very upset as her silver jewellary had turned black, and lost its lustre. Her father is a science teacher and he washed and cleaned the jewellary using toothpaste and brought the shine back. Why does the silver jewellary tarnishes when left open ?
Answer» Solution :SILVER jewellary reacts with gases and MOISTURE of air DUE to which it tarnishes and get CORRODED.

Discussion

3235.	If an element has a low ionization energy then it is likely to be _______ ["metallic"// "non-metallic"]
Answer» SOLUTION :METALLIC

Discussion

3236.	Sunny and Bunny have taken spectra for the following transitions .Spectra taken by sunny consited of bright lines on a dark background .Spectra taken by Bunny consisted of dark lines on a bright background .Identify the electronic transitions corrseponding to the spectra taken by sunny and Bunny .What are those spectra called? (i) n= 5 to n=2 (ii) n=3 to n=6 (iii) n=5 to n=7 (iv) n=3 to n=1 (v) n=1 to n=2 (vi) n=5 to n=3
Answer» Solution :When an electron in an atom gains energy it gets excited to a higer energy state fron the ground state,The electron being unstable in the exiced state loses energy and comes back to the ground state either directly or in steps .During this process the bright lines CORRESPONDING to the transitions are formed on the dark background .This is CALLED emission spectrum.When the electrons get exicted to higher energy and dark lines corresponding to the transitions are formed on the bright background.This is called absorption specrum . (i) n=5 to n=2 `rarr` emission spectum (II) n=4 to n =6 `rarr` absorption spectrum (III) n=5 to n =7 `rarr` absorption spectrum (IV) n=3 to n =1 `rarr` emission spectrum . (v) n= 1 to n=2 `rarr` absorption spectrum (vi) n=5 to n = 3 `rarr` emission spectrum

Discussion

3237.	Summary of all chemical equations : SO_2Cl_2 + H_2O rarr_________ + ________
Answer» SOLUTION :`SO_2 + Cl_2 + 2H_2O RARR H_2SO_4 + 2HCL`

Discussion

3238.	Summary of all chemical equations : SO_2 + C rarr__________ + _______
Answer» SOLUTION :`SO_2 + C RARR CO_2 + S DARR`

Discussion

3239.	Summary of all chemical equations : H_2S + H_2SO_4 rarr__________ + ________
Answer» SOLUTION :`H_2 + H_2SO_4 RARR SO_2 + 2H_2O`

Discussion

3240.	Summary of all chemical equations : Cl_2 + H_2S rarr_________ + _______
Answer» SOLUTION :`Cl_2 + H_2S RARR 2HCL + S`

Discussion

3241.	Summary of all chemical equations : CaC_2O_4 + H_2SO_4 rarr_________ + ___________
Answer» SOLUTION :`CaC_2O_4 + H_2SO_4 RARR CaSO_4 + H_2C_2O_4`

Discussion

3242.	In Br_(3)O_(8) compound, oxidation number of bromine is:
Answer» 6 4 16 20 Answer :C

Discussion

3243.	Sulphuric acid is an hydracid.
Answer» SOLUTION :NA

Discussion

3244.	Sulphuric acid is added to carrry out electrolysis of water . How does the addition of sulphuricacid produce a conductingsolution ?
Answer» Solution :Sulphuric acid being a strong ELECTROLYTE IONISES completely and gives more HYDROGEN ions are sulphate ions which MAKE the solution conducting .

Discussion

3245.	Sulphure dissolves in water with the same activity.
Answer» ANSWER :F

Discussion

3246.	Sulphur shows allotropism.
Answer» ANSWER :T

Discussion

3247.	Sulphur dioxide is not recognized by
Answer» ODOUR TEST litmus PAPER test acidified `K_(2)Cr_(2)O_(7)` colour test Answer :D

Discussion

3248.	Sulphur dioxide gas should not be inhaled directly because
Answer» it SMELLS LIKE a rotten egg it EXCITES laughter it can damage lungs it smells like rotten fish Answer :C

Discussion

3249.	Sulphur dioxide gas is dried by passing through concentrated H_(2)SO_(4) because.
Answer» concentrated `H_(2)SO_(4)`because concentrated `H_(2)SO_(4)` oxidizes`SO_(2)` concentrated `H_(2)SO_(4)` is a disbasic ACID none of the above ANSWER :A

Discussion

3250.	Sulphide ores are generally concentrated by the :
Answer» levigation leaching FROTH floatation calcination ANSWER :C

Discussion

Explore topic-wise InterviewSolutions in .

The acidity and alkalinity of a compound is represented on a scale known as

The acid produced in our stomach is :

The acid present in orange juice is citric acid.

The absolute charge on the electron is.

The ability of the metals to be drawn into thin wires is known as

The ability of carbon atom to link with other carbon atom is known as_____.

The3 elements which were predicted byMendeleev for which he left blank spaces in theperiodic table.

The 18th group of elements in the periodic table is called

Thallous compounds are more common and stable than thallic compounds. Justify this statement.

TFM in soaps represents………………….content in soap.

Tell whether heat is evolved or absorbed when quick lime is added to water.

Tellurium :_________ :: Radium : Metal

Tell me Why cannot a chemical change be normally reversed?

Tell me Why is it always essential tobalance a chemical equation?

Tell me Can rusting of iron take place in distilled water?

Tell me What happens when carbon dioxide gas is passed through lime water and why does it disappear on passing excess carbon dioxide?

Tartaric acid is present in :

Tap water is

Taking the example of an element of atomic number 16, explain how the electronic configuration of the atom of an element relates to its position in the Modern Periodic Table and how valency of an element is calculated on the basis of its atomic number.

Taking the example of an element of atomic number 16, explain how the electronic configurationof the atom of an element relates to its position in the Modern Periodic Table and how valency of an element is calculated on the basis of its atomic number.

takesome carboncompounds( naphthalene, camphor, alcohol) onebyoneona spatulaand burnthem *observethe natureof theflameand notewhethersmokeis produced *placea metalplateabovetheflame. Istherea depositionon theplatein caseof anyof thecompounds?

Take copper nitrate in a test tube heat it over the flame. (i)What is the colour of cupric nitrate ? (ii)What do you observe ? (iii)Name the type of reaction that takes place. (iv)Write the balanced equation.

Take 3 g of barium hydroxide in a test tube, now add about 2 g ammonium chloride and mix the contents with the help of a glass rod. Now touch the test tube from outside. Write the balanced chemical equation of the reaction involved.

Take 3 g of barium hydroxide in a test tube, now add about 2 g ammonium chloride and mix the contents with the help of a glass rod. Now touch the test tube from outside. State the inference about the type or reaction occurred.

Take 3 g of barium hydroxide in a test tube, now add about 2 g ammonium chloride and mix the contents with the help of a glass rod. Now touch the test tube from outside. What do you feel on touching the test tube ?

Take10 gofcommonsalt anddissolveit in40gof water. Findtheconcentrationof solutionin termsof weightpercent .

Switching off lights and fans when not in use can save

Suspension of slaked lime in water in known as

Surface of metals loses their brightness when kept in air for a long time. Why ?

Surekha was very upset as her silver jewellary had turned black, and lost its lustre. Her father is a science teacher and he washed and cleaned the jewellary using toothpaste and brought the shine back. What value of Surekha.s father is seen in this act ?

Surekha was very upset as her silver jewellary had turned black, and lost its lustre. Her father is a science teacher and he washed and cleaned the jewellary using toothpaste and brought the shine back. How had the toothpaste got the shine of silver back ?

Surekha was very upset as her silver jewellary had turned black, and lost its lustre. Her father is a science teacher and he washed and cleaned the jewellary using toothpaste and brought the shine back. Why does the silver jewellary tarnishes when left open ?

If an element has a low ionization energy then it is likely to be _______ ["metallic"// "non-metallic"]

Summary of all chemical equations : SO_2Cl_2 + H_2O rarr_________ + ________

Summary of all chemical equations : SO_2 + C rarr__________ + _______

Summary of all chemical equations : H_2S + H_2SO_4 rarr__________ + ________

Summary of all chemical equations : Cl_2 + H_2S rarr_________ + _______

Summary of all chemical equations : CaC_2O_4 + H_2SO_4 rarr_________ + ___________

In Br_(3)O_(8) compound, oxidation number of bromine is:

Sulphuric acid is an hydracid.

Sulphuric acid is added to carrry out electrolysis of water . How does the addition of sulphuricacid produce a conductingsolution ?

Sulphure dissolves in water with the same activity.

Sulphur shows allotropism.

Sulphur dioxide is not recognized by

Sulphur dioxide gas should not be inhaled directly because

Sulphur dioxide gas is dried by passing through concentrated H_(2)SO_(4) because.

Sulphide ores are generally concentrated by the :

takesome carboncompounds( naphthalene, camphor, alcohol) onebyoneona spatulaand burnthem observethe natureof theflameand notewhethersmokeis produced placea metalplateabovetheflame. Istherea depositionon theplatein caseof anyof thecompounds?

Summary of all chemical equations : SO_2Cl_2 + H_2O rarr_ +

Summary of all chemical equations : SO_2 + C rarr____ + _

Summary of all chemical equations : H_2S + H_2SO_4 rarr__ +

Summary of all chemical equations : Cl_2 + H_2S rarr___ + _

Summary of all chemical equations : CaC_2O_4 + H_2SO_4 rarr_ + ___