8881 + Interview Questions in Chemistry in Class 10 Page 50 InterviewSolution

2451.	What is the color of the product formed after burning Magnesium Ribbon
Answer» White Blue Yellow Pink Answer :A

Discussion

2452.	Which of the following hydroxides is most basic ?
Answer» `Be(OH)_(2)` `BA(OH)_(2)` `Ca(OH)_(2)` `Mg(OH)_(2)` ANSWER :B

Discussion

2453.	Write the name and molecular formula of the first member of the homologous series of alkynes.
Answer» ANSWER :ETHYNE, `C_(2)H_(2)`.

Discussion

2454.	What is tooth enamel chemically ? State the condition when it starts corroding. What happens when food particles left in the mouth after eating degrades ? Why do doctor suggest the use of tooth powder/tooth paste to prevent tooth decay ?
Answer» Solution :White TOOTH enamel is calcium phosphate and a very hard substance, which GETS AFFECTED when PH of our mouth falls below 5.5. It happens because BACTERIA present in our mouth breakdown sugar and food particles into acids which damage our teeth by corroding them. To prevent tooth decay, after eating one should clean mouth thoroughly with tooth power or tooth paste, which is basic in nature. It nuetralises the excess of acid produced in the mouth.

Discussion

2455.	Which information not obtained by the balanced chemical equation ?
Answer» Physical states of reactants and products. Symbols and FORMULAE of all the SUBSTANCES involved in a PARTICULAR REACTION. Number of atoms `//` MOLECULES of the reactants and products formed. Whether a particular reaction is actually feasible or not. Solution :Whether aparticular reaction is actually feasible or not

Discussion

2456.	When a carbonate reacts with an acid, the gas released is
Answer» SOLUTION :NA

Discussion

2457.	Which of the following pairs are members of a homologous series?
Answer» `CH_3O CH_3, CH_3CH_2 - OH` `CH_3 - CHO, CH_3 CH_2 CHO` `CH_3 CH_2 COOH, CH_3 COOCH_3` `(CH_3)_2 CH - OH, CH_3 CH_2 -OH` SOLUTION :`CH_3 - CHO, CH_3 CH_2 CHO`

Discussion

2458.	To which sides of a chemical equation the reactants and products are represented ?
Answer» Solution :In chemical equation, REACTANTS are written on LEFT side of an ARROW (`to`), while products are written on RIGHT side of an arrow (`to`).

Discussion

2459.	What is meant by classification of elements ?
Answer» Solution :Arrangement of the KNOWN elements in an ORDER so that these can be studied EASILY and PROPERLY is called classification.

Discussion

2460.	Which of the following is an example of strong electrolyte?
Answer» `NH_4 OH `SOLUTION NAOH `CH_3 COOH` HCN Solution :NaOH

Discussion

2461.	Which physical properties of metals are used in the following situations ? (i) Gold is used to make ornaments (ii) Nickel is used in strings of guitar.
Answer» SOLUTION :(i) metals are DUCTILE metals have (SHINING APPEARANCE) lustrous. (ii) sonorous ductile

Discussion

2462.	Thevalueof Avogardro's numberis _______.
Answer» SOLUTION :`6.023xx10^(23)`

Discussion

2463.	Write the chemical formula of bleaching powder. Write balanced chemical equation involved in the preparation of bleaching powder and write in three uses.
Answer» SOLUTION :CHEMICAL formula -`CaOCl_2` chemical EQUATION- `Ca(OH)_2+Cl_2 to CaOCl_2+H_2O` Uses: (ii) For bleaching cotton and linen in textile industry (ii) As an oxidising agent in a chemical industry. (iii) For disinfecting water

Discussion

2464.	Write the molecular formula of the third member of the homologous series of an organic compound with general formula C_n H_(2n+1) OH
Answer» SOLUTION :`C_3H_7OH " or " CH_3CH_2H_2OH`

Discussion

2465.	Which is the incomplete period in the ModernPeriodic table?
Answer» Solution :SINCE the Modem Periodic table is COMPLETE there is no INCOMPLETE period.

Discussion

2466.	Which of the following pairs can produce a colloidal solution ?
Answer» Sodium CHLORIDE and water Soil and water Glucose and water NONE of these Answer :C

Discussion

2467.	What property of an element is measured by electronegativity.
Answer» SOLUTION :POWER to ATTRACT ELECTRON(s)

Discussion

2468.	Write the chemical formula for bleaching powder. How is bleaching powder prepared ? For what purpose is it used in paper factories ?
Answer» SOLUTION :`CaOCl_2` , Bleaching powder is prepared by PASSING `Cl_2` gas through dry slaked lime. `Ca(OH)_2 + Cl_2 to CaOCl_2 + H_2O` It is USED for bleaching wood pulp in paper FACTORIES.

Discussion

2469.	(a) What is meant by catenation? Name two element which exhibit the property of catenation (b) Write the names and structural formula al all the possible isomers of hexane.
Answer» Solution :Catenation is the capacity of an ATOM to FORM BONDS with other atoms of the same element. Carbon and SILICON SHOW the property of cartenation.

Discussion

2470.	What are structural isomers? Name the first member of alkanes that shows structural isomerism.
Answer» Solution :Compounds with IDENTICAL molecular formula but different structures of CALLED strutual ISOMERS. Butane or `C_(4)H_(10)`

Discussion

2471.	The value of ionic product of water ar 25^(@) C is……..
Answer» SOLUTION :`1XX10^(-14)`

Discussion

2472.	When a student added zinc granules to dilute HCl, a colurless and odourless gas was evolved. When it was tested with a burning match stick, it was observation that :
Answer» The match STICK CONTINUED to burn brilliantly The match stick burnt SLOWLY with a blue flame The match stick EXTINGUISHED and the GAS burnt with pop sound The match stick burnt with an orange flame Solution :The match stick extinguished and the gas burnt with pop sound

Discussion

2473.	Write the balanced chemical equations for the following reactions : (i) When copper is heated in air. (ii) When aluminium oxide reacts with sodium hydroxide.
Answer» Solution :(i) `2Cu + O_(2) rarr 2CuO` (ii) `4Al + 3O_(2) rarr 2Al_(2)O_(3)` (III) `Al_(2)O_(3) + 2NAOH rarr 2NaAlO_(2) + H_(2)O`

Discussion

2474.	What is meant by water of Crystallisation ? How do you show that copper sulphate crystal contains water of crystallisation ?
Answer» SOLUTION :When we heat copper sulphate crystals the water is REMOVED and the salt turn white. If you MOISTURIZE the crystals again with water you will find that the blue olour of crystals reappears.

Discussion

2475.	What is hydrogenation? What is its industrial application?
Answer» Solution :The addition of hydrogen to an unsaturated hydrocarbon to get a saturated hydrocarbon is called HYDROGENATION. This process takes PLACE in the presence of nickel or palladium metals as catalyst. It has an important industrial application. It is used to prepare VEGETABLE ghee from vegetable oils. Vegetable oils such as groundnut oils, cottonseed oils and mustard oils are unsaturated and also contain double bonds (C=C). On hydrogenation (addition of hydrogen), in the presence of nickel as catalyst, vegetable oil PRODUCES vanaspati ghee.

Discussion

2476.	What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?
Answer» Solution :The TWO PROPERTIES are: (a)CATENATION, the ABILITY to FORM bonds with other atoms of carbon (b) Tetravalency of carbon.

Discussion

2477.	What would you see when ethyne is bubbled through a solution of bromine in carbon tetrachloride?
Answer» SOLUTION :BROMINE solution will BECOME COLOURLESS

Discussion

2478.	What is the maximum number of water molecules that can attach with one water molecule through intermolecular hydrogen bonds?
Answer» 2 3 4 1 Answer :C

Discussion

2479.	Which of the following statements is correct with regard to the classification of elements ?
Answer» ELEMENTS in modern periodic table are arranged on the basis of increasing ATOMIC masses. Elements in modern periodic table are arranged on the basis of DECREASING atomic numbers. In modern periodic table, the element nickel of lower atomic mass is KEPT before the element cobalt of higher atomic mass. In modern periodic table, the isotopes of chlorine having different atomic masses are kept in the same group. Answer :A::B::C::D

Discussion

2480.	When bitten by ant, the sting causes irritation due to the presence of
Answer» a BASE in the sting formic acid in the sting POISONOUS chemicals both (a) and (B) ANSWER :B

Discussion

2481.	What are the applications of Avogadro's Law.
Answer» Solution :i. It explains Gay-Lussac.s law. II. It helps in the determination of atomicity of gases. iii. Molecular formula of gases can be derived using Avogadro.s law. iv. It determines the RELATION between molecular mass and vapour DENSITY. V. It helps to determine gram molar volume of all gases. (i.e, 22.4 litres at S.T.P)

Discussion

2482.	What is the IUPAC name of the acid in vinegar?
Answer» SOLUTION :ETHANOIC ACID

Discussion

2483.	What is the concentration of hydrogen ions of a solution when its pH is 8?
Answer» SOLUTION :`[H^(+)]=10^(-PH)=10^(-8)`

Discussion

2484.	What is the role of cryolite and fluorspar during the extraction of aluminium? However, addition of these produces a harmful gas. Explain.
Answer» Solution :(i) Nature and property of an electrolyte. (ii) Electrolyte used for rthe extraction of ALUMININUM. (iii) Thermal stability of the electrolyte. (iv) RELATION between the presence of impuirty and melting point of solid. (v) Effect of addition of CRYOLITE and fluorspar on the melting point of the electrolyte. (vi) Mechanism of conduction of electricity. (vii) Effect of addition of cryolite and fluorspar on the conduction electricity. (viii) Product product obtained at the ANDOE during ELECTROLYSIS. (ix) Anodic product obtained at the end of the electrolysis.

Discussion

2485.	Which of the following reaction does not take place?
Answer» `Cu + underset (conc) (2HC1) toCuC1_(2) + H_(2)` `Cu + underset (conc) (2H_(2)SO_(4)) OVERSET (Heat) (RARR)CuSO_(4) + SO_(2) + 2H_(2) O` `3Cu + underset (DILUTE) (8HNO_(3)) to 3Cu(NO_(3))_(2) + 2NO + 4H_(2)O` `Cu + 2AgNO_(3) to Cu(NO_(3))_(2) + 2Ag` Answer :A

Discussion

2486.	The valueof d(C-C) distanceis experimentally found to be1.54Å. Find itscovalentradius .
Answer» SOLUTION :`d(C-C)=1.54Å` `R(C) =(d(c-c))/(2)=(1.54)/(2)=0.77Å`

Discussion

2487.	Write the molecular formulae of oxides of the following elements by referring to the Mendeleev's periodic table.
Answer» SOLUTION :

Discussion

2488.	The valency of an element is
Answer» the mass of the ELEMENT displacing 1 PART by the mass of hydrogen the mass of the element combining with 8 parts by mass of oxygen the number of atoms of hydrogen combin ing with 1 atom of the GIVEN element the number of atoms in 1 MOLECULE of the given element Answer :C

Discussion

2489.	When CO_(2)gas is dissolved in water, the pH of the solution becomes.
Answer» more than 7 equal to 7 less than 7 none of these ANSWER :C

Discussion

2490.	What are the main products of electrolysis of molten lead bromide ? Name the eletrodes at which each product is produced .
Answer» Solution :(i) LEAD is PRODUCED at CATHODE (ii) Bromine is produced at ANODE .

Discussion

2491.	When a sample of KNO_(3) is subjected to heating, the volume of oxygen liberatedwas sufficient for thecombustion of one mole of ethylene. For giving same amount of oxygen, what is the amount of lead nitrate required ot be decomposed? Also, find out thevolume occupied by the gaseous products atSTP during this decomposition.
Answer» Solution :`2KNO_(3) to 2KNO_(2) + O_(2)` 1 mole of ethylene requires 3 moles of oxygen `2PB(NO_(3))_(2) to 2PbO + 4 NO_(2) + O_(2)` 6 moles of `Pb(NO_(3))_(2) ` is REQUIRED to given 3 moles of oxygen `:.` Weight of `Pb(NO_(3))_(2) = 6 xx 330 = 1980` g VOLUME occupied by gaseous `(NO_(2) and O_(2))` products ` = 15 xx 22.4 " L at STP " = 336` L

Discussion

2492.	Which of the following contains maximum number of molecules?
Answer» `"1 G of "CO_(2)` `"1 g of "N_(2)` `"1 g of "H_(2)` `"1 go of "CH_(4)` SOLUTION :Hint : `"No. of MOLES"=("Mass")/("Atomic mass")(or) ("Mass")/("Molecular mass")` `"No. of moles of 1 g of "CO_(2)=(1)/(44)` `"No. of molecules"=(1)/(44)xx6.023xx10^(23)` `=1.368xx10^(22)" molecules of "CO_(2)` (b) 1 g of `N_(2)` `"No. of molecules "=(1)/(28)xx6.023xx10^(23)` `=2.151xx10^(22)" molecules of "N_(2)` (C ) 1 gof `H_(2)` `"No. of molecules "=(6.023xx10^(23)xx1)/(2)` `=3.011xx10^(23)" molecules of "H_(2)` (d) 1 g of `CH_(4)` `"No. of molecules "=(6.023xx10^(23)xx1)/(16)` `=3.764xx10^(22)" molecules of "CH_(4)` So (c ) is the correct answer.

Discussion

2493.	Though covalent character increases form lithium fluoride to lithium iodide, lithium fluoride is insoluble in water while lithium iodide is soluble. Justify the above statement.
Answer» Solution :SINCE the size of halide ion increase down the group, the ease of getting polarised by a CATION also increases. Thus, `Li^(+)` ion can polarise `I^(-)` ion to a greater extent and thus from LiF to LiI covalent character increases. Hence, we EXPECT that LiF is more soluble in water and LiI is less soluble or not soluble in water. The solubility of an ionic compound in water depends on the relative VALUES of lattice energy and HYDRATION energy. The substance becomes soluble in water if hydration energy exceeds lattice energy. From LiF to LiI, lattice energy decreases while hydration energy increases. Since lattice energy of LiF is much greater than hydration energy, it is insoluble in water and thus solubility in water increases from LiF to LiI.

Discussion

2494.	The reactive metals do not occur in nature in the _____ state.
Answer» ANSWER :FREE

Discussion

2495.	The reactions given below represent the processes of reduction to obtain metals from their respective ores. Arrange them in the following order. Sodium, aluminium, zinc, chromium, iron, copper and mercry (1) Metal oxide + metal sulphide to Metal + SO_(2) (2) Metal oxide + CO to Metal + CO_(2) (3) Metal oxide + C to CO (4) Metal oxide to Metal + O_(2) (5) Meta oxide overset(Delta)to Metal + O_(2) (6) "Metal oxide"+"Aluminium"to"Aluminium oxide"+"Metal" (7) Metal chloride to Metal + Chlorince
Answer» 7 4 3 6 2 1 5 7 4 3 6 2 5 1 1 3 2 4 6 7 5 7 4 5 2 6 1 5 Solution :(i) METAL chloride `to` Metal + Chlorine (ii) Metal oxide `to` Metal + `O_(2)` (iii) Metal oxide + C `to` Metal + CO (iv) `"Metal oxide"+"alumininm"to"aluminium oxide" +"metal"` (v) `"Meta oxide"+COTO"Metal"+CO_(2)` (vi) `"Metal oxide"+"Metal SUPHIDE"to"Metal"+SO_(2)` (vii) `"Metal oxide"overset(Delta)to"Metal"+O_(2)`

Discussion

2496.	The reaction which occurs in the pressence of sunlight
Answer» SOLUTION :PHOTOCHEMICAL

Discussion

2497.	The reaction used to join railway tracks involves reducing agent
Answer» AL Mg C CO Solution :Thermite process is used `Fe_(2)O_(3)+2Al to 2Fe+Al_(2)O_(3)` The REDUCING AGENT is Al.

Discussion

2498.	The reaction that is not asscoiated with the middle region of blast furnace during smelting is ______.
Answer» ANSWER :`C+O_(2)toCO_(2)`

Discussion

2499.	The reaction taking place at the anode of a zinc copper galvanic cell ____________
Answer» `ZntoZn^(2+)+2e^(-)` `ZN^(2+)+2e^(-)TOZN` `CutoCu^(2+)+2e^(-)` `CU^(2+)+2e^(-)to Cu` Answer :B

Discussion

2500.	The reaction taken place when ethanol is heated with Conc. H_(2)SO_(4) of 443K is……………….
Answer» oxidation reduction intermolecular dehydration intramolecular dehydration Answer :D

Discussion

Explore topic-wise InterviewSolutions in .

What is the color of the product formed after burning Magnesium Ribbon

Which of the following hydroxides is most basic ?

Write the name and molecular formula of the first member of the homologous series of alkynes.

What is tooth enamel chemically ? State the condition when it starts corroding. What happens when food particles left in the mouth after eating degrades ? Why do doctor suggest the use of tooth powder/tooth paste to prevent tooth decay ?

Which information not obtained by the balanced chemical equation ?

When a carbonate reacts with an acid, the gas released is

Which of the following pairs are members of a homologous series?

To which sides of a chemical equation the reactants and products are represented ?

What is meant by classification of elements ?

Which of the following is an example of strong electrolyte?

Which physical properties of metals are used in the following situations ? (i) Gold is used to make ornaments (ii) Nickel is used in strings of guitar.

Thevalueof Avogardro's numberis _______.

Write the chemical formula of bleaching powder. Write balanced chemical equation involved in the preparation of bleaching powder and write in three uses.

Write the molecular formula of the third member of the homologous series of an organic compound with general formula C_n H_(2n+1) OH

Which is the incomplete period in the ModernPeriodic table?

Which of the following pairs can produce a colloidal solution ?

What property of an element is measured by electronegativity.

Write the chemical formula for bleaching powder. How is bleaching powder prepared ? For what purpose is it used in paper factories ?

(a) What is meant by catenation? Name two element which exhibit the property of catenation (b) Write the names and structural formula al all the possible isomers of hexane.

What are structural isomers? Name the first member of alkanes that shows structural isomerism.

The value of ionic product of water ar 25^(@) C is……..

When a student added zinc granules to dilute HCl, a colurless and odourless gas was evolved. When it was tested with a burning match stick, it was observation that :

Write the balanced chemical equations for the following reactions : (i) When copper is heated in air. (ii) When aluminium oxide reacts with sodium hydroxide.

What is meant by water of Crystallisation ? How do you show that copper sulphate crystal contains water of crystallisation ?

What is hydrogenation? What is its industrial application?

What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?

What would you see when ethyne is bubbled through a solution of bromine in carbon tetrachloride?

What is the maximum number of water molecules that can attach with one water molecule through intermolecular hydrogen bonds?

Which of the following statements is correct with regard to the classification of elements ?

When bitten by ant, the sting causes irritation due to the presence of

What are the applications of Avogadro's Law.

What is the IUPAC name of the acid in vinegar?

What is the concentration of hydrogen ions of a solution when its pH is 8?

What is the role of cryolite and fluorspar during the extraction of aluminium? However, addition of these produces a harmful gas. Explain.

Which of the following reaction does not take place?

The valueof d(C-C) distanceis experimentally found to be1.54Å. Find itscovalentradius .

Write the molecular formulae of oxides of the following elements by referring to the Mendeleev's periodic table.

The valency of an element is

When CO_(2)gas is dissolved in water, the pH of the solution becomes.

What are the main products of electrolysis of molten lead bromide ? Name the eletrodes at which each product is produced .

Which of the following contains maximum number of molecules?

Though covalent character increases form lithium fluoride to lithium iodide, lithium fluoride is insoluble in water while lithium iodide is soluble. Justify the above statement.

The reactive metals do not occur in nature in the _____ state.

The reaction which occurs in the pressence of sunlight

The reaction used to join railway tracks involves reducing agent

The reaction that is not asscoiated with the middle region of blast furnace during smelting is ______.

The reaction taking place at the anode of a zinc copper galvanic cell ____________

The reaction taken place when ethanol is heated with Conc. H_(2)SO_(4) of 443K is……………….