8881 + Interview Questions in Chemistry in Class 10 Page 14 InterviewSolution

651.	Which of the following acid does not react with metals?
Answer» SULPHURIC ACID phosphoric acid carbonic acid NITRIC acid Answer :C

Discussion

652.	What is the pH of a solution in which [H^(+)] is 10^(-10) mole/L ? Is it an acidic, alkaline or neutral solution?
Answer» SOLUTION :PH = 10, ALKALINE

Discussion

653.	What is the common name of CH_(3)COOH ?
Answer» ANSWER :ACETIC ACID or VINEGAR.

Discussion

654.	Under what soil condition do you think a farmer would treat the soil of his field with quick lime (calcium oxide) or slaked lime (calcium hydroxide) or chalk ? (calcium carbonate) ?
Answer» Solution :Most of the PLANTS grow best when the pH of the SOIL is close to 7. If the soil is too acidic or too basic , the plants grow BADLY or do not grow at all . As QUICK lime , slaked lime or chalk are all alkaline substances, these would be added to the soil by the farmer when soil is highly acidic .

Discussion

655.	Write the balanced chemical equations for the following reactions. (a) Calcium hydroxide + Carbon dioxide rarr Calcium carbonate + Water (b) Zinc + Silver nitrate rarr Zinc nitrate + Silver (d) Barium chloride + Potassium sulphate rarr Barium sulphate + Potassium chloride
Answer» Solution :(a) `Ca(OH)_(2)+CO_(2)rarrCaCO_(3)+H_(2)O` (B) `Zn+2AgNO_(3)rarrZn(NO_(3))_(2)+2Ag` (c ) `2Al+3CuCl_(2)rarr2AlCl_(3)+3Cu` (d) `BaCl_(2)+K_(2)SO_(4)rarrBaSO_(4)+2KCl`

Discussion

656.	Which of the following is not a mixture?
Answer» air sea water ICE soil SOLUTION :ice

Discussion

657.	Write the molecular formulae of the first two alkynes.
Answer» SOLUTION :`(i) C_2H_2 (II) C_3H_4`

Discussion

658.	What is soft soap?
Answer» Solution :Soaps, which are PREPARED by the SAPONIFICATION of OILS or fats with potassium salts, are known as soft soaps. They are used for CLEANSING the body.

Discussion

659.	Which of the following is not a mineral acid ?
Answer» a)hydrochloric ACID b)CITRIC acid c)Sulphuric acid d)NITRIC acid Solution :Citric acid

Discussion

660.	The value of Gram molar volume at STP is 11.2 litres.
Answer» SOLUTION :Correct STATEMENT : The VALUE of Gram molar VOLUME at STP is 22.4 litres.

Discussion

661.	Thermal stability of metal oxides can be compared using electrochemical series. Explain.
Answer» Solution :Elements with higher standard reduction potential have lesser tendency of losing electrons. They are less electropositive and form OXIDES that are less STABLE towards heat. These metals are generally placed on the top in electrochemical SERIES when they are arranged in decreasing order of redcution potential `(+ve)` values and form unstable oxides towards heat, that is, these oxides are decomposed on heating. In case of weak electrolytes, DEGREE of dissociation increases with dilution.

Discussion

662.	Which metal will react readily with cold water?a. Goldb. Silverc. Magnesiumd. Calcium
Answer» Gold Silver MAGNESIUM CALCIUM Solution :Calcium

Discussion

663.	The standard oxidation potential of silver electrode is given as - 0.799 V. The standard reduction potential of copper electrode is given as 0.33 V. Find out the emf of the cell constituted by these two electrodes. Also write the half -cell reactions involved in the cell and given cell representation
Answer» SOLUTION :(i) Difference in STANDARD ELECTRODE potentials of the electrodes. (ii) Difference between oxidation and reduction potentials (III) Comparison of standard electrode potentials of the respective metals. (iv) Identification of anode and cathode in the ELECTROCHEMICAL cell. (v) Calculation of emf of the cell

Discussion

664.	Write notes on (i) saturated solution (ii) unsaturated solution
Answer» Solution :(i) Saturated solution: A solution in which no more solute can be dissolved in a definite amount of the SOLVENT at a GIVEN temperature is called saturated solution. e.g. 36 g of sodium chloride in 100 g of WATER at `25^@ C` forms saturated solution. (II) Unsaturated solution: Unsaturated solution is one that contains less solute than that of the saturated solution at a given temperature. e.g. 10 g or 20 g or 30 g of Sodium chloride in 100 g of water at `25^@ C` forms an unsaturated solution.

Discussion

665.	To obtain a diminished image of an object from a concave mirror, position of the object should be
Answer» <P>between C and F beyond C between P and F at F Answer :B

Discussion

666.	What are minerals ?
Answer» SOLUTION : A MINERAL may be a SINGLE comound or a COMPLEX mixture of various compound of metals FOUND in earth e.g.Clay `Al_(2)O_(3)`.`2SiO_(2)`.`2H_(2)O` is the mineral of Aluminium .

Discussion

667.	Which of the following statement(s) is (are) correct about the renewable natural resource ?
Answer» It gets exhausted soon. It is inexhaustible It REAPPEARS at the RATE it is used It cannot be REPLENISHED within a short period. ANSWER :B::C

Discussion

668.	Which of the following non-metals is a liquid?
Answer» BROMINE CARBON sulphur chlorine SOLUTION :bromine

Discussion

669.	What is the cathode , anode and electrolyte used in the electrolytic refiningof copper ?
Answer» Solution :(i) Cathode : A THIN plate of pure coppermetals. (II) Anode : A block of impurecopper METAL. (ii) ELECTROLYTE : Copper sulphatesolution acidifiedwith sulphuric acid .

Discussion

670.	You are provided the solutions of sodium hydroxide (A), hydrochloric acid (B), sodium chloride ( C) and phenolphthalein (P) separately. All the solutions are colourless. How will you identify the solutions of acid, base and salt?
Answer» Solution :(i) A + P `to` Pink solution (II) Pink solution + B `to` Pink colour DISAPPEARS (iii) C + P `to` No colour CHANGE

Discussion

671.	Which element has : (i) two shells, both of which are completely filled with electrons ? (ii) the electronic configuration, 2, 8, 2. (iii) a total of three shells, with four electrons in its valence shell ? (iv) a total of two shells, with three electrons in its valence shell ? (v) Twice as many electrons in its second shell as in its first shell ?
Answer» Solution :(a) NE (B) MG ( c) Si (d) B (e) C

Discussion

672.	Write the chemical name and formula of gypsum. What happens when gypsum is heated at 373K. Write chemical equation for the reaction.
Answer» SOLUTION :Chemical nam of gypsum: Calcium sulphate DIHYDRATE Chemical FORMULA of gypsum: `CaSO_4.2H_2O` When Gypsum is HEATED at 373K, it will form plaster of paris and water. `CaSO_4.2H_2O to^(373 K) CaSO_4.1/2 H_2O+1 1/2 H_2O` (Gypsum ) (Plaster of paris)

Discussion

673.	Whatisgrammolecularmass ?
Answer» SOLUTION :It themolecularmassofa givensubstanceisexpressedin GRAM , ITIS KNOWNAS grammolecularmassof thatsubstance .

Discussion

674.	What is the mass of sodium chloride that would be needed to form a saturated solution in 50 g of water at 30^@ C. Solubility of sodium chloride is 36 g at 30^@ C?
Answer» Solution : At `30^@ C`, 36 g of sodium chloride is DISSOLVED in 100 g of water. `therefore `Mass of sodium chloride that would be need for 100 g of water = 36 g `therefore ` Massof sodiumchloridedissolvedin 50g of100gof water `=( 36 xx 50 )/( 100 )= 18 g `

Discussion

675.	Therr elements A, B and C have atomic numbers as x,x + 1 and x + 2. The atomic size of C is greater than that of B but positions of B is less than that of A. Predict the positions of A, B amd C in the periodic table and justify the trend in atomic size.
Answer» SOLUTION :As the atomic numbers of A,B and C differ by 1 UNIT each they must be belonging to adjacent group. Along a period the atomic size decreases till the VII A group and then INCREASES till the zero group. As the atomic size of C is greater than B though it DIFFERS by one unit in its atomic number it must be a zero group element. Though the atomic number of B is greater than A, it has smaller size than Band this shows that B is a halogen, that is VII A group and A CHALCOGEN, that is, VI A group.

Discussion

676.	Why AgBr shows both frenkel and schottky defect
Answer» Because SIZE of `AG^+` is smaller than `BR^-` Because RATIO of size of `Ag^+` and `Br^-` is of intermediate range Because size of `Ag^+` is same as that of `Br^-` None Answer :B

Discussion

677.	Which statement is ture for reaction ? 2H_(2) (g) + O_(2) (g) rarr 2H_(2) O (g)
Answer» `S = +ve` `H GT U` `-H LT U` H = U Answer :A

Discussion

678.	Which postulate was disproved by Wohler ? Explain with example.
Answer» Solution :Carbon atom possesses characteristic features of tetravalency and catenation, and due to this it FORMS a large number of compounds. Among these, many compounds have the same non-carbon atom or group of atoms attached to DIFFERENT carbon chains. These compounds were initially extracted from natural substances. It was believed that organic compounds could only be formed within a living system, that is, it was POSTULATED that .vital force. was necessary for their synthesis. German scientist, Friedrich Wohler disproved this in 1826. EXAMPLE : He prepared organic compound urea by heating inorganic compound ammonium cyanate. `underset("cyanate")underset("Ammonium")(overset(+)(N)H_(4)bar(O)NC)overset(Delta)toNH_(2)-underset("Urea")underset(O)underset(\|\|)(C)-NH_(2)`

Discussion

679.	When is the force experienced by current carrying conductor placed in a magnetic field largest ?
Answer» SOLUTION :The FORCE experienced by current carrying conductor placed in a magnetic FIELD is largest when the current carrying conductor is placed in a DIRECTION PERPENDICULAR to that of magnetic field.

Discussion

680.	Which of the uniquefeature (s) of carbon enables it to form a large number of compounds ?
Answer» CATENATION COVALENCY TETRAVALENCY both (a) and (C) ANSWER :D

Discussion

681.	which period contains only two elements ?
Answer» Second FIRST Third FIFTH ANSWER :B

Discussion

682.	Which causes more severe burns?
Answer» COLD Water Hot Water Steam Both B and C Answer :C

Discussion

683.	The valency o a phosphate ion is
Answer» -1 -2 3 -3 Solution :Phosphate ION is `PO_(4)^(3-)`, Its valency is -3.

Discussion

684.	What is the basis of the Modern Periodic Table? Why lithium with atomic number 3 and potassium with atomic number 19 placed in group one? What are the atomic numbers of the first two elements in the second group?
Answer» Solution :a] Modern Periodic Table is based on the atomic number - the number of protons in an atom which decides its electronic configuration and hence its properties. All the ELEMENTS are arranged in increasing order of their atomic number. Elements of SIMILAR properties are placed in the same vertical column. b] Electronic configuration of Lithium is (2, 1) and POTASSIUM is (2, 8, 8, 1). Since both have one valence electron, they share similar chemical properties and are hence placed in group I. c] The first element in the second group comes after Lithium with atomic number 3. Hence, its atomic number is 4. The second element in the second group has 8 electrons more (since periodicity OCCURS at intervals of 2, 8, 8, etc.) and hence, its atomic number is 4+8 = 12.

Discussion

685.	Write the following componentsfor the electrolytic refining of a piece of impure copper : (ii) The cathode.
Answer» Solution :CATHODE : A THIN strip of pure COPPER .

Discussion

686.	There are 7 electrons in the outermost 'L' shell of an element. Predict the period and group in the periodic table this element belongs to.
Answer» Solution :Period -2, GROUP -17. (Electronic configuration of ELEMET = 2,7)

Discussion

687.	What is the effect of an increase in concentration of H^+ ions? 1M HCl or 1M CH_3COOH.
Answer» Solution :1M HCl has a HIGHER concentration of `H^+` IONS, because when HCl dissolves in water it DISSOCIATES completely into ions value while `CH_3COOH` is a WEAK acid and does not dissociate into ions completely.

Discussion

688.	Write the balanced chemical equation for the process of photosynthesis and the conditions of the reaction giving the physical states of all the substances.
Answer» Solution :`6CO_(2)(g)+6H_(2)O(L)underset("chlorophyll")overset("SUNLIGHT")(to)C_(6)HI_(2)O_(6)(s)+6O_(2)(g)`

Discussion

689.	Which of the following statements is (are) correct about the reaction given below ? NH_(4)OH + HCI to NH_(4) CI +H_(2)O
Answer» `NH_(2)OH` ACTS the OXIDISING agent . The reaction is a neutralization one. HCI acts as thereducing agent. This is a double DISPLACEMENT reaction. ANSWER :B::D

Discussion

690.	Write the IUPAC name of the compound CH_3 CH_2- undersetoverset(\|)(OH)(C)H - CH_3
Answer» SOLUTION : (a) There are 4 C atoms in the longest CONTINUOUS chain involving -OH group, THEREFORE, the root word is .but. (b) Only C-C bonds APPEAR in the carbon chain, therefore, primary suffix is .ane.. (c) There is OH group at carbon 2 of the chain, therefore, secondary suffix is 2-o.. Base name = root word + primary suffix = but + ane = butane (d) There is one-CH, radical at carbon 3 of the chain. Therefore, prefix is 3-methyl.. Thus, the IUPAC name of the given compound is derived as: Prefix + Base name -e + Secondary suffix 3-Methyl + butane -e+ 2-ol = 3-methylbutan-2-ol

Discussion

691.	Which of the following are not olfactory indicators ?
Answer» ONION JUICE Turmeric Red-cabbage juice Olive oil ANSWER :B::C

Discussion

692.	Two atoms are said to be isobars if
Answer» they have same atomic number but different MASS number they have same number of ELECTRONS but different number of neutrons they have same number of neutrons but different number of electrons sum of the number of protons and neutrons is same but the number of protons is different Solution :ISOBARS have same mass number but different atomic number Mass no. = of p+no. of n `""_(7)^(14)N` and `""_(6)^(14)C`

Discussion

693.	Which among the following pairs of acid and base are weak respectively ?
Answer» HCOOH and `NH_(4)OH` HCL and NaOH `CH_(3)COOH and KOH` `HCIO_(4) and CsOH` SOLUTION :HCOOH is a weak acid and `NH_(4)OH` is a weak BASE.

Discussion

694.	which of the following statements does not apply to elements belonging to the same period of the periodic table ?
Answer» The number of valence electrons increases on moving from left to RIGHT. The atomic SIZE increases from left and right The atomic size GOES on DECREASING from left to right The metallic character of elements DECREASES from left to right . Answer :D

Discussion

695.	Which of the following reaction is not endothermic in nature?
Answer» BREAKING in bonds digestion of food combustion of Carbon evaporation of water Answer :C

Discussion

696.	Write the hydrogenationreactions of ethene
Answer» SOLUTION :`CH_2= CH_2 + H - H to CH_3 - CH_3`

Discussion

697.	What will be the formula and electron dot structure of cyclopentane ?
Answer» Solution :he general formula of cycloalkane is `C_(n)H_(2N)`, hence, molecular formula of CYCLOPENTANE is `C_(5)H_(10)`. The electron dot structure of cyclopentane is SHOWN below :

Discussion

698.	There is no change in the mass of H_(2)SO_(4) during the elestrolysis of water which has been acidified with sulphuric acid . Illustrate giving reasons .
Answer» Solution :There is an increase in the mass of `H_(2)SO_(4)` near anode , but there is EQUAL decrease in the mass of `H_(2)SO_(4)` near cathde . Thus , there is no net change in the mass of `H_(2)SO_(4)` during the ELECTROLYSIS of acidified water USING platinum electrodes .

Discussion

699.	Translate the statements into chemical equations and then balance them: Potassiam metal reacts with water to give potassium hydroxide and hydrogen gas.
Answer» Solution :`underset("Potassium")(2K(s)) +underset("WATER")(2H_(2)O(1)) to underset("Potassium hydroxide")(2KOH)+ underset("Hydrogen")(H_(2))`

Discussion

700.	When megnesium is burnt in air, a white ash remains as left over. Aqueous solution of this white ash turns red litmus blue. The formula of the white ash and type of reaction respectively are
Answer» MGO, non-redox reaction Mgo, redox reaction `Mg(OH)_(2)`, decomposition reaction MgO, DISPLACEMENT reaction Answer :B

Discussion

Explore topic-wise InterviewSolutions in .

Which of the following acid does not react with metals?

What is the pH of a solution in which [H^(+)] is 10^(-10) mole/L ? Is it an acidic, alkaline or neutral solution?

What is the common name of CH_(3)COOH ?

Under what soil condition do you think a farmer would treat the soil of his field with quick lime (calcium oxide) or slaked lime (calcium hydroxide) or chalk ? (calcium carbonate) ?

Write the balanced chemical equations for the following reactions. (a) Calcium hydroxide + Carbon dioxide rarr Calcium carbonate + Water (b) Zinc + Silver nitrate rarr Zinc nitrate + Silver (d) Barium chloride + Potassium sulphate rarr Barium sulphate + Potassium chloride

Which of the following is not a mixture?

Write the molecular formulae of the first two alkynes.

What is soft soap?

Which of the following is not a mineral acid ?

The value of Gram molar volume at STP is 11.2 litres.

Thermal stability of metal oxides can be compared using electrochemical series. Explain.

Which metal will react readily with cold water?a. Goldb. Silverc. Magnesiumd. Calcium

Write notes on (i) saturated solution (ii) unsaturated solution

To obtain a diminished image of an object from a concave mirror, position of the object should be

What are minerals ?

Which of the following statement(s) is (are) correct about the renewable natural resource ?

Which of the following non-metals is a liquid?

What is the cathode , anode and electrolyte used in the electrolytic refiningof copper ?

You are provided the solutions of sodium hydroxide (A), hydrochloric acid (B), sodium chloride ( C) and phenolphthalein (P) separately. All the solutions are colourless. How will you identify the solutions of acid, base and salt?

Write the chemical name and formula of gypsum. What happens when gypsum is heated at 373K. Write chemical equation for the reaction.

Whatisgrammolecularmass ?

What is the mass of sodium chloride that would be needed to form a saturated solution in 50 g of water at 30^@ C. Solubility of sodium chloride is 36 g at 30^@ C?

Therr elements A, B and C have atomic numbers as x,x + 1 and x + 2. The atomic size of C is greater than that of B but positions of B is less than that of A. Predict the positions of A, B amd C in the periodic table and justify the trend in atomic size.

Why AgBr shows both frenkel and schottky defect

Which statement is ture for reaction ? 2H_(2) (g) + O_(2) (g) rarr 2H_(2) O (g)

Which postulate was disproved by Wohler ? Explain with example.

When is the force experienced by current carrying conductor placed in a magnetic field largest ?

Which of the uniquefeature (s) of carbon enables it to form a large number of compounds ?

which period contains only two elements ?

Which causes more severe burns?

The valency o a phosphate ion is

What is the basis of the Modern Periodic Table? Why lithium with atomic number 3 and potassium with atomic number 19 placed in group one? What are the atomic numbers of the first two elements in the second group?

Write the following componentsfor the electrolytic refining of a piece of impure copper : (ii) The cathode.

There are 7 electrons in the outermost 'L' shell of an element. Predict the period and group in the periodic table this element belongs to.

What is the effect of an increase in concentration of H^+ ions? 1M HCl or 1M CH_3COOH.

Write the balanced chemical equation for the process of photosynthesis and the conditions of the reaction giving the physical states of all the substances.

Which of the following statements is (are) correct about the reaction given below ? NH_(4)OH + HCI to NH_(4) CI +H_(2)O

Write the IUPAC name of the compound CH_3 CH_2- undersetoverset(|)(OH)(C)H - CH_3

Which of the following are not olfactory indicators ?

Two atoms are said to be isobars if

Which among the following pairs of acid and base are weak respectively ?

which of the following statements does not apply to elements belonging to the same period of the periodic table ?

Which of the following reaction is not endothermic in nature?

Write the hydrogenationreactions of ethene

What will be the formula and electron dot structure of cyclopentane ?

There is no change in the mass of H_(2)SO_(4) during the elestrolysis of water which has been acidified with sulphuric acid . Illustrate giving reasons .

Translate the statements into chemical equations and then balance them: Potassiam metal reacts with water to give potassium hydroxide and hydrogen gas.

When megnesium is burnt in air, a white ash remains as left over. Aqueous solution of this white ash turns red litmus blue. The formula of the white ash and type of reaction respectively are