8881 + Interview Questions in Chemistry in Class 10 Page 73 InterviewSolution

3601.	Relative molecular mass is equal to ………….. .
Answer» SOLUTION :`2XX"VAPOUR DENSITY"`

Discussion

3602.	Relativemolecularmass is onlya ratio, it has________.
Answer» SOLUTION :no UNIT

Discussion

3603.	Relative atomic mass is otherwise known as ……………….. .
Answer» SOLUTION :STANDARD ATOMIC WEIGHT

Discussion

3604.	relativeatomicmass isexpressedin grams .
Answer» SOLUTION :CORRECT STATEMENT : Relativeatomicmass hasno UNIT .

Discussion

3605.	Relativeatomicmass hasno unit . Explain ..
Answer» SOLUTION :Atomicmassisthe MASSOF ANATOM . Therelativeatomicmass of anelementhasnoatomicunitbecauseatomsare INSUPPORTABLE .

Discussion

3606.	Reduction of alumina that is obtained, either by Hall's proces or Bayer's process, to aluminium metal is carred out by electrolysis. During this process, cryolite and fluorspar are added to alumina, the entire mixture is covered with coke powder. (i) Why can alumina not be directly electrolysed? (ii) What is the role of addition of cryolite and fluorspar? (iii) What are the different cathodic and anodic reaction taking place during electrolysis?
Answer» Solution :(i) Alumina can be directly elecrtolysed because alumina has high thermal stability and hence, very high temperature is required for melting pure alumina. (ii) Cryolite and fluorspar are ADDED to alumina in ORDER to decrease the melting point of alumina and increase the electrical conductivity of the mixture. (iii) For the electrolysis of alumina, cryolite and fluorspar are added to it. The mixture undergoes electrolysis in the following way. `Al_(2)O_(3)to2Al^(+3)+3O^(-2)` `Na_(3)AlF_(6)to3Na^(+)+Al^(+3)+6F^(-)` `CaF_(2)toCa^(+2)+2F^(-2)` At anode : `O^(2-)-2e^(-)to[O]""C+2[O]toCO_(2)` At cathode : `Al^(+3)+3e^(-)toAl`

Discussion

3607.	Reduction is the loss of oxygen or gain of hydrogen.
Answer» SOLUTION :As PER DEFINITION of REDUCTION.

Discussion

3608.	Reducing agent undergoes …………..
Answer» SOLUTION :OXIDATION

Discussion

3609.	Reducing agent are also called __________.
Answer» ANSWER :REDUCTANT

Discussion

3610.	Redox reactions are reaction during which reaction during which electron transfer takes place.Here magnesium atom transfers two electrons one each to the two chlorine atoms. (i)What are the products of this reaction? (ii)Write the balanced equation for the complete reaction. (iii)Which element is being oxidized? (iv)Which element is being reduced? (v)Write the reduction part of the reaction.
Answer» SOLUTION :(i)Magnesium atom is converted to `MG^(2+)` ion.Two CHLORINE atoms are converted to `2Cl^(-)` ions so the products are `Mg^(2+)` ion and `2Cl^(-)` ions. (ii)`UNDERSET("Magnesium")(Mg_((s)))+underset("Chlorine")(Cl_(2(g)))tounderset("Magnesium chloride")(MgCl_(2(s)))` (iii)Mg atom is being oxidised by donating 2 electrons. (iv)`Cl_(2)` molecule is being reduced by accepting 2 electrons. (v)`Cl_(2)+2e^(-)to2Cl^(-)`. It is a reduction in which gain of `E^(-)` take place.

Discussion

3611.	Red-cabbage juice is a _____ indicator .
Answer» SOLUTION :HOUSEHOLD

Discussion

3612.	Rectified spirit on heating with Conc. H_(2)SO_(4) for about 5 to 6 hours and allowed to stand for 12 hours to get absolute alcohol.
Answer» SOLUTION :Rectified SPIRIT on HEATING with QUICKLIME for about 5 to 6 hours and allowed to stand for 12 hours to get ABSOLUTE alcohol.

Discussion

3613.	Rectified spirit is an aqueous solution which contains about……………of ethanol.
Answer» 0.955 0.755 0.555 0.455 Solution :RECTIFIED SPIRIT is a MIXTURE of 95.5% of ETHANOL and 4.5% of WATER.

Discussion

3614.	Rechargingof mobilebatteryis a irreversiblereaction .
Answer» SOLUTION :CORRECT STATEMENT: rechagingof mobilebattery is a REVERSIBLEREACTION .

Discussion

3615.	Reagent which distinguish alkane and alkene is……………….
Answer» `Br_(2)//H_(2)O`<BR>`H_(2)O` `C_(2)H_(5)OH` Ether Answer :A

Discussion

3616.	Read the following paragraph and answer the questions given below: In the Modem Periodic table, the elements are arranged in the increasing order of their atomic numbers . Thi s arrangement is based on the Modern Periodic law, which states that the properties of elements are a periodic function of their atomic numbers. In the Modern Peroidic table, each column is called a group and each row is called a period. Elements within the same group show similarity and ggradation in properties. This is due to the same number of electrons in the outermost shell. Which pair of elements do you think will havesimilar properties? (a) Sodium and Argon (b) Sodium and Potassium (c) Potassium and Neon
Answer» Solution :The PAIR of elements having similar properties are,(b) Sodium and Potassium as they BELONG to the same GROUP i.e. group 1 of Modem PERIODIC table.

Discussion

3617.	Read the following paragraph and answer the questions given below: In the Modem Periodic table, the elements are arranged in the increasing order of their atomic numbers . Thi s arrangement is based on the Modern Periodic law, which states that the properties of elements are a periodic function of their atomic numbers. In the Modern Peroidic table, each column is called a group and each row is called a period. Elements within the same group show similarity and ggradation in properties. This is due to the same number of electrons in the outermost shell. What is the number of valence electrons in an element of group 1 and group 18 respectively?
Answer» Solution :The number of VALENCE ELECTRONS in an ELEMENT of GROUP 1 is 1 and the number of valence electrons in an element of group 18 is 8.

Discussion

3618.	Read the following paragraph and answer the questions given below: In the Modem Periodic table, the elements are arranged in the increasing order of their atomic numbers . Thi s arrangement is based on the Modern Periodic law, which states that the properties of elements are a periodic function of their atomic numbers. In the Modern Peroidic table, each column is called a group and each row is called a period. Elements within the same group show similarity and ggradation in properties. This is due to the same number of electrons in the outermost shell. What is the trend in the variation of valency while going down a group?
Answer» SOLUTION :All elements in a group have the same NUMBER of electrons in the outermost SHELL. Therefore, down the group, VALENCY remains the same. Valency of group 1 elements is 1 and that of group 2 elements is 2. The valency of group 18 elements is ZERO because they are noble gases with completed outermost shell.

Discussion

3619.	Read the following paragraph and answer the questions given below: In the Modem Periodic table, the elements are arranged in the increasing order of their atomic numbers . Thi s arrangement is based on the Modern Periodic law, which states that the properties of elements are a periodic function of their atomic numbers. In the Modern Peroidic table, each column is called a group and each row is called a period. Elements within the same group show similarity and ggradation in properties. This is due to the same number of electrons in the outermost shell. How many groups are there in the modem periodic table?
Answer» SOLUTION :There are 18 GROUPS in MODEM PERIODIC table.

Discussion

3620.	Read the following paragraph and answer the questions given below: In the Modem Periodic table, the elements are arranged in the increasing order of their atomic numbers . Thi s arrangement is based on the Modern Periodic law, which states that the properties of elements are a periodic function of their atomic numbers. In the Modern Peroidic table, each column is called a group and each row is called a period. Elements within the same group show similarity and ggradation in properties. This is due to the same number of electrons in the outermost shell. State the law on which mode,n periodic table is based.
Answer» Solution :Modem periodic table is BASED on modemperiodic law which states that .Properties of ELEMENTS are a periodic function of their ATOMIC numbers..

Discussion

3621.	Read the following paragraph and answer the questions given below: Dmitri Ivanovich Mendeleev was the first to classify elements on the basis of their fundamental property, the atomic mass, and also on the similarity of chemical properties. When Mendeleev started his work, 63 elements were known. He examined the relationship between the atomic masses of the elements and their physical and chemical properties. Among chemical properties Mendeleev concentrated on the compounds formed by the elements with oxygen and hydrogen. He selected hydrogen and oxygen as they were very reactive and formed compounds with most elements . The formulae of the hydrides and oxideswere treated as one of the basic properties of an element for its classification. He sorted out the elements with similar properties and pinned the cards together on a wall. He observed that most of the elements got a place in the periodic table and were arranged in the order of their increasing atomic masses. It was also observed that there occurs a periodic recurrence of elements with similar physical and chemical properties . On this basis Mendeleev formulated a periodic law which states that "The properties of the elements arethe periodic function of their atomic masses". What is Mendeleev's Periodic Law?
Answer» SOLUTION :Mendeleev.s Periodic Law is "The PROPERTIES of ELEMENTS are the periodic function of their atomic MASSES".

Discussion

3622.	Read the following paragraph and answer the questions given below: Dmitri Ivanovich Mendeleev was the first to classify elements on the basis of their fundamental property, the atomic mass, and also on the similarity of chemical properties. When Mendeleev started his work, 63 elements were known. He examined the relationship between the atomic masses of the elements and their physical and chemical properties. Among chemical properties Mendeleev concentrated on the compounds formed by the elements with oxygen and hydrogen. He selected hydrogen and oxygen as they were very reactive and formed compounds with most elements . The formulae of the hydrides and oxideswere treated as one of the basic properties of an element for its classification. He sorted out the elements with similar properties and pinned the cards together on a wall. He observed that most of the elements got a place in the periodic table and were arranged in the order of their increasing atomic masses. It was also observed that there occurs a periodic recurrence of elements with similar physical and chemical properties . On this basis Mendeleev formulated a periodic law which states that "The properties of the elements arethe periodic function of their atomic masses". How many elements were known whenMendeleev started his work?
Answer» Solution :63 elements were known when MENDELEEV STARTED his WORK.

Discussion

3623.	Read the following paragraph and answer the questions given below: Dmitri Ivanovich Mendeleev was the first to classify elements on the basis of their fundamental property, the atomic mass, and also on the similarity of chemical properties. When Mendeleev started his work, 63 elements were known. He examined the relationship between the atomic masses of the elements and their physical and chemical properties. Among chemical properties Mendeleev concentrated on the compounds formed by the elements with oxygen and hydrogen. He selected hydrogen and oxygen as they were very reactive and formed compounds with most elements . The formulae of the hydrides and oxideswere treated as one of the basic properties of an element for its classification. He sorted out the elements with similar properties and pinned the cards together on a wall. He observed that most of the elements got a place in the periodic table and were arranged in the order of their increasing atomic masses. It was also observed that there occurs a periodic recurrence of elements with similar physical and chemical properties . On this basis Mendeleev formulated a periodic law which states that "The properties of the elements arethe periodic function of their atomic masses". What type of relationship of elements wasexamined by Mendeleev?
Answer» Solution :Mendeleev examined the relationship between the atomic masses of the ELEMENTS and their PHYSICAL and CHEMICAL properties .

Discussion

3624.	Read the following paragraph and answer the questions given below: Dmitri Ivanovich Mendeleev was the first to classify elements on the basis of their fundamental property, the atomic mass, and also on the similarity of chemical properties. When Mendeleev started his work, 63 elements were known. He examined the relationship between the atomic masses of the elements and their physical and chemical properties. Among chemical properties Mendeleev concentrated on the compounds formed by the elements with oxygen and hydrogen. He selected hydrogen and oxygen as they were very reactive and formed compounds with most elements . The formulae of the hydrides and oxideswere treated as one of the basic properties of an element for its classification. He sorted out the elements with similar properties and pinned the cards together on a wall. He observed that most of the elements got a place in the periodic table and were arranged in the order of their increasing atomic masses. It was also observed that there occurs a periodic recurrence of elements with similar physical and chemical properties . On this basis Mendeleev formulated a periodic law which states that "The properties of the elements arethe periodic function of their atomic masses". What is meant by periodicity according toMendeleev?
Answer» SOLUTION :(i)Mendeleev observed that ELEMENTS with SIMILAR PHYSICAL and chemical properties reoccur when elements were arranged in the increasing order of their atomic MASSES. (ii)So according to Mendeleev, the recurrence of elements with similar physical and chemical properties when they are arranged in an increasing order of their atomic masses, is called periodicity.

Discussion

3625.	Read the following paragraph and answer the questions given below: Dmitri Ivanovich Mendeleev was the first to classify elements on the basis of their fundamental property, the atomic mass, and also on the similarity of chemical properties. When Mendeleev started his work, 63 elements were known. He examined the relationship between the atomic masses of the elements and their physical and chemical properties. Among chemical properties Mendeleev concentrated on the compounds formed by the elements with oxygen and hydrogen. He selected hydrogen and oxygen as they were very reactive and formed compounds with most elements . The formulae of the hydrides and oxideswere treated as one of the basic properties of an element for its classification. He sorted out the elements with similar properties and pinned the cards together on a wall. He observed that most of the elements got a place in the periodic table and were arranged in the order of their increasing atomic masses. It was also observed that there occurs a periodic recurrence of elements with similar physical and chemical properties . On this basis Mendeleev formulated a periodic law which states that "The properties of the elements arethe periodic function of their atomic masses". What was the basis of Mendeleev's classification?
Answer» Solution :Mendeleev.s CLASSIFICATION was BASED on thefundamental PROPERTY of atomic mass and alsoon the similarity of CHEMICAL properties.

Discussion

3626.	Read each description given belowand say whetherit fitsfor ethanol or ethanoicacid. It is usedto preserve foodand fruitjuices .
Answer» SOLUTION :ETHANOIC ACID

Discussion

3627.	Read each description given belowand say whetherit fitsfor ethanol or ethanoicacid. On coolingit is frozen to form ice flakeswhichlook like a glacier .
Answer» SOLUTION :ETHANOIC ACID

Discussion

3628.	Read each description given belowand say whetherit fitsfor ethanol or ethanoicacid. It is a clear liquidwith a burningtaste .
Answer» SOLUTION :ETHANOL .

Discussion

3629.	Read each description given belowand say whetherit fitsfor ethanol or ethanoicacid. It is used to preserve biological specimens in laboratories.
Answer» SOLUTION :ETHANOL .

Discussion

3630.	……….Reacts with sodium hydroxide.
Answer» Cu Ag Cr Zn

Discussion

3631.	Reactivity of magnesium metal with dilute hydrochloric acid is maximum. Why?
Answer» Solution :Since magnesium is very active METAL, it reacts with DILUTE HYDROCHLORIC acid vigorously liberating hydrogen.

Discussion

3632.	Reactive metals are good reducing agents. The most suitable example related to this is
Answer» `PbO + C to pb + CO` `3MnO_2 + 4Al to 2Al_2O_3 + 3MN` `ZnO + C to Zn + CO` `CuO + H_2 to CU + H_2O` SOLUTION :`3MnO_2 + 4Al to 2Al_2O_3 + 3Mn`

Discussion

3633.	Reactions in which energy is absorbed are known as endothermic reactions.
Answer» SOLUTION :These are CALLED EXOTHERMIC REACTIONS.

Discussion

3634.	Reaction of zinc with copper sulphate to form zinc sulphate and copper is an example of double decomposition reaction.
Answer» SOLUTION :In DOUBLE displacement REACTIONS, there is an exchange of ions.

Discussion

3635.	Reaction of sodium hydroxide with hydrochloric acid is an example for ………
Answer» COMBINATION reaction Thermolysis reaction Neutralization reaction Precipitation reaction Answer :A::C

Discussion

3636.	Reaction of ethanoic acid with ethanol in presence of acid catalyst forms ..........
Answer» SOLUTION :ESTER (ETHYL ACETATE) and WATER

Discussion

3637.	Reaction of carboxylic acid with sodium carbonate produces carbon dioxide.
Answer» ANSWER :1

Discussion

3638.	Reaction of alcohol with sodium forms ..........
Answer» SOLUTION :HYDROGEN GAS `(H_(2))`

Discussion

3639.	Reaction , in whichheatis absorbed, arecalled ______.
Answer» SOLUTION :ENDOTHERMIC REACTIONS

Discussion

3640.	Reaction, CaCO_(3) overset(Delta)to CaO + CO_(2) is a . ………… reaction.
Answer» SOLUTION :DECOMPOSITION

Discussion

3641.	Reaction : 4NH_(3)(g) + 5O_(2)(g) to 4NO(g) + 6H_(2)O(g)is an example of: (i) displacement reaction (ii) combustion reaction (iii) redox reaction (iv) neutralisation reaction
Answer» (i) and (IV) (II) and (III) (iii) and (iv) (i) and (ii) SOLUTION :(ii) and (iii)

Discussion

3642.	Reactants A and B react together and forms zinc chloride and hydrogen gas. Identify A and B. Write the chemical equation.
Answer» Solution :The reactant A is a ZINC METAL and the reactant B is HYDROCHLORIC acid. `Zn+ 2HCL to ZnCl_(2)+H_(2)`

Discussion

3643.	Reactant rarr Products + Energy this release of energy gives what information about the rection
Answer» REACTION is endothermic Reaction is exothermic Precipitate is being formed Gas is liberated Answer :B

Discussion

3644.	RCC is
Answer» the concrete having an iron framework INSIDE it as a SUPPORT the crushed cement in which more gravel is added prepared by ADDING CALCIUM CHLORIDE to the limestone and calcium silicate none of the above Answer :A

Discussion

3645.	Ratio of number of Faradays of electricity required to deposit magnesium, aluminium and sodium in equimolar ratio on electrolysis of their respective molten salt is _____
Answer» `2 : 3 : 2` `2 : 1 : 1` `2 : 3 : 1` `4 : 6 : 1` Solution :Electrode REACTIONS involved are `Mg^(+2) + 2e^(-) rarr Mg` `AL^(+3) + 3e^(-) rarr Al` `Na^(+) + e^(-) rarr Na` 1 mole of Mg REQUIRES 2 FARADAYS 1 mole of Al requires 3 Faradays. 1 mole of sodium requires 1 Faraday Ratio of number of Faradays `= 2 : 3: 1`

Discussion

3646.	A gas with molecular formula C_(n)H_(2n + 2) diffuses through a porous plug at a rate 1//6th of the rate of diffusion of hydrogen gas under similar condtition. The formula of the gas is:
Answer» SOLUTION :Let the molecular weight of the hydrocarbon be `M_(X)` and its rate of diffusion be `r_(x)` `r_(H_(2))/r_(x) =SQRT(M_(x)/M_(H_(2))), r_(x) = 1//6r_(H_(2))` `:. r_(H_(2))/r_(x)=6=sqrt(M_(x)/2)` ` RARR 36 XX 2 = M_(x)` ` rArr M_(x) = 72` Molecular weight of thehydrocarbon is 72. Let thenumber of carbon atoms present in one molecule of the hydrocarbon be be m. `:' ` the hydrocarbon is saturated, the number of hydrogen atoms present in that hydrocarbon molecule is 2 m + 2 `:. (12 xxm) +2 m + 2 = 72` ` rArr 14 m +2 = 72 rArr m = 5` `:.` Molecular formula of the hydrocarbon is `C_(5)H_(12)`.

Discussion

3647.	Random Movement of particles was discovered by
Answer» ROBERT BROWN E. GOLDSTEIN JAMES Chadwick Wilheln Weins Solution :Robert Brown

Discussion

3648.	Rancidity can be prevented by .
Answer» adding antioxidants. storing the FOOD in FREEZE. KEEPING food AWAY from the light. All of the given. Solution :All of the given.

Discussion

3649.	Rakesh visited the government hospital to meet his cousin. He observed the medicine in dark bottles were not stored properly. They were not kept away from light and heat. Rakesh immediately reported the same to the medical superintendent and made sure that all medicines are stored properly. What value of Rakesh is seen in this act ?
Answer» Solution :RAKESH EXPRESSED the value of responsible and AWARE CITIZEN.

Discussion

3650.	Rakesh visited the government hospital to meet his cousin. He observed the medicine in dark bottles were not stored properly. They were not kept away from light and heat. Rakesh immediately reported the same to the medical superintendent and made sure that all medicines are stored properly. Why do some medicines are kept in refrigerator ?
Answer» Solution :Some medicines DECOMPOSE and BECOME dangerous and toxic at temperature little HIGHER than room temperature. Hence, they are STORED in refrigerator.

Discussion

Explore topic-wise InterviewSolutions in .

Relative molecular mass is equal to ………….. .

Relativemolecularmass is onlya ratio, it has________.

Relative atomic mass is otherwise known as ……………….. .

relativeatomicmass isexpressedin grams .

Relativeatomicmass hasno unit . Explain ..

Reduction is the loss of oxygen or gain of hydrogen.

Reducing agent undergoes …………..

Reducing agent are also called __________.

Red-cabbage juice is a _____ indicator .

Rectified spirit on heating with Conc. H_(2)SO_(4) for about 5 to 6 hours and allowed to stand for 12 hours to get absolute alcohol.

Rectified spirit is an aqueous solution which contains about……………of ethanol.

Rechargingof mobilebatteryis a irreversiblereaction .

Reagent which distinguish alkane and alkene is……………….

Read each description given belowand say whetherit fitsfor ethanol or ethanoicacid. It is usedto preserve foodand fruitjuices .

Read each description given belowand say whetherit fitsfor ethanol or ethanoicacid. On coolingit is frozen to form ice flakeswhichlook like a glacier .

Read each description given belowand say whetherit fitsfor ethanol or ethanoicacid. It is a clear liquidwith a burningtaste .

Read each description given belowand say whetherit fitsfor ethanol or ethanoicacid. It is used to preserve biological specimens in laboratories.

……….Reacts with sodium hydroxide.

Reactivity of magnesium metal with dilute hydrochloric acid is maximum. Why?

Reactive metals are good reducing agents. The most suitable example related to this is

Reactions in which energy is absorbed are known as endothermic reactions.

Reaction of zinc with copper sulphate to form zinc sulphate and copper is an example of double decomposition reaction.

Reaction of sodium hydroxide with hydrochloric acid is an example for ………

Reaction of ethanoic acid with ethanol in presence of acid catalyst forms ..........

Reaction of carboxylic acid with sodium carbonate produces carbon dioxide.

Reaction of alcohol with sodium forms ..........

Reaction , in whichheatis absorbed, arecalled ______.

Reaction, CaCO_(3) overset(Delta)to CaO + CO_(2) is a . ………… reaction.

Reaction : 4NH_(3)(g) + 5O_(2)(g) to 4NO(g) + 6H_(2)O(g)is an example of: (i) displacement reaction (ii) combustion reaction (iii) redox reaction (iv) neutralisation reaction

Reactants A and B react together and forms zinc chloride and hydrogen gas. Identify A and B. Write the chemical equation.

Reactant rarr Products + Energy this release of energy gives what information about the rection

RCC is

Ratio of number of Faradays of electricity required to deposit magnesium, aluminium and sodium in equimolar ratio on electrolysis of their respective molten salt is _____

A gas with molecular formula C_(n)H_(2n + 2) diffuses through a porous plug at a rate 1//6th of the rate of diffusion of hydrogen gas under similar condtition. The formula of the gas is:

Random Movement of particles was discovered by

Rancidity can be prevented by .