2599 + Interview Questions in Chemistry in Class 9 Page 37 InterviewSolution

1801.	Calculate the mass of water required to produce 36 g of glucose during the process of photosynthesis in plants .
Answer» SOLUTION :`underset(108 g) (6H_(2)O) + 6 CO_(2) to C_(6) underset(180 g) (H_(12) O_(6))`21.6 g

Discussion

1802.	Calculate the mass of the following: (i) 0.5 mole of N_(2) gas (mass from mole of molecule) (ii) 0.5 mole of N atoms (mass from mole of atom) (iii) 3.011 xx 10^(23) number of N atoms (mass from number) (iv) 6.022 xx 10^(23) number of N_(2) molecules (mass from number)
Answer» Solution :(i) mass = `"molar mass" xx "number of moles"` `IMPLIES m = M xx n = 28 xx 0.5` = 14 g (ii) mass = `"molar mass" xx "number of moles"` `implies m=M xx n = 14 xx 0.5` = 7 g (iii) The number of moles (n)= `("given number of particles")/("Avogadro number")` `=(N)/(N_(0))= (3.011 xx 10^(23))/(6.022 xx 10^(23))` `implies m = M xx n = 14 xx (3.011 xx 10^(23))/(6.022 xx 10^(23)) = 14 xx 0.5` = 7G (iv) `n = (N)/(N_(0))` `implies m = M xx (N)/(N_(0))` `= 28 xx (6.022 xx 10^(23))/(6.022 xx 10^(23)) = 28 xx 1` = 28 g

Discussion

1803.	Calculate the mass of the following: (i) 0.5moles of O_(2) gas(ii) 0.5moles of O atoms (iii) 3.011xx10^(23)"atoms of O"(iv) 6.022xx10^(23)"molecules of "O_(2) (Givem: Gram atomic mass of oxygen=16g) Gram of molecular mass of oxygen (O_(2))=32g)
Answer» Solution :(i) 0.5 mole of `O_(2)` gas No. of moles`= ("Mass of "O_(2) " in grams")/("Gram molecular mass")= (m)/(M)` `therefore` Mass of `O_(2)` is gram (m) = No. of moles `xx M 0.5 xx (32G) = 16g` (ii) 0.5 moles of oxygen (O) atoms `"No. of gram atoms"=("Mass of oxygen (O) is grams")/("Gram atomic mass")=(m)/(M)` Mass of oxygen of (O) in grams (m) = No. OFMOLES `xx M = 0.5 xx (16g(0 = 8 g` (iii)`3.011 xx 10^(23)` atoms of oxgen (O) Step I : Calculationof no. of gram atoms of oxygen `"No.of gram atoms"=("No.of atoms of oxygen")/("Avogadro's no.of atoms")= (N)/(N_(0))` `= (3.011 xx 10^(23) )/(6.022xx 10^(23)) = 0.5` gram atom StepII :Calculation of mass of oxgyen (O) atoms Mass of oxygen (O) atoms =Gramatomic mass of oxygen `xx` No.ofgram atomsof oxygen `= (16g) xx 0.5 = 8 g` (iv) `6.022 xx 10^(23)` molecules of oxygen`(O_(2))` Step I: Calculation of no.of gram moles of oxygen. `"No.of gram moles"=("No.of atoms of oxygen")/("Avogadro's no.of atoms")= (N)/(N_(0))` `= (6.022 xx 10^(23))/(6.022 xx 10^(23)) = 1` gram mol. Step II: Calculationof mass of oxgyen`(O_(2))` molecules. Mass of oxygen `(O_(2))` molecules = Gram molecular mass of oxygen `xx` Noof grammoles of oxgyen `= (32 g) xx 1 = 23 g`.

Discussion

1804.	Calculate the mass of sodium sulphate required to prepared its 20% solution in 100g of water ?
Answer» Solution :In a 20% solution containing 100G water the mass percentage of water = 100 - 20 = 80% 80% of solution is 100 GM 100% of solution is `(100)/(80)` gm 20% of solution is `(100)/(80) xx 20` = 25 gm Hence to PREPARE 20% (w/w) solution in 100 gram of water, 25 gm of sodium sulphate is needed.

Discussion

1805.	Calculate the mass of sulphuric acid required to prepare its 20% (mass percent) solution in 100 g of water ?
Answer» Solution :Mass percent =`("Mass of solute")/("Mass of water")xx 100` `20 = (x)/((x + 100)) xx 100` `20X + 2000 = 100x` or `80X = 2000 or x = (2000)/(80) = 25 G`

Discussion

1806.	Calculate the mass of magnesium deposited during the electrolysis of molten magnesium chloride by passing 193 amperes of current for 600 minutes.
Answer» SOLUTION :MASS `= (Mct)/(ZF), Mg^(+2) + 2e^(-) to Mg` Mass `= (24 xx 193 xx 600 xx 60)/(2 xx 96500) = 864 g`

Discussion

1807.	Calculate the mass of a charged particle in CGS units if its charge is x coulomb and specific charge is y coulomb/g.
Answer» Solution :The MASS of PARTICLE in CGS units is `(e)/((e)/(m))G=(X)/(y)g`.

Discussion

1808.	Calculate the mass of 12.0 xx 10^(14) atoms of hydrogen.
Answer» SOLUTION :`1.99 XX 10^(-9) G`

Discussion

1809.	Calculate the mass in grams of 0.2 mole of water (H_(2)O) . ( H = 1 , O = 16)
Answer» SOLUTION :`3.6` G

Discussion

1810.	Calculate the Molecular formula unit mass of ZnO , given atomic masses ofZn = 654 and O = 164
Answer» Solution :Formula UNIT mass of Zno=Atomic mass of ZN + Atomic mass of `0=65+ 16 = 81` Formula unit mass of `Na_(2) O=2x`Atomic mass of Na+ Atomic mass of O `2 x 23 +16=62 u.` Formula unit mass of `K_(2) CO_(3),=-2x` Atomic mass of K + Atomic mass of C+3 x Atomic mass of `0 = 2x39 + 12+ 2x 16=78 +12 +32 = 122 u.`

Discussion

1811.	Calculate the formula unit masses of ZnO, Na_(2)O, K_(2)CO_(3). Given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, 0 = 16 u.
Answer» Solution :The formula unit MASS of, ZnO = 65 U+16 u = 81 u `Na_(2)O = (2 xx 23 u) + 16 u = 46 u +16 u = 62 u` `K_(2)CO_(3) = (2 xx 39 u) + 12 u + (3 xx 16 u) = 78 u +12 u +48 u = 138 u`

Discussion

1812.	Calculate the formula unit mass of CaCl_(2).
Answer» Solution :Formula unit MASS of `CaCl_(2)` = (ATOMIC mass of Ca) + 2 (atomic mass of CL) = (40) + 2(35.5) = 40 + 71 = 111 u

Discussion

1813.	Calculate the formula unit mass of Al_(2)(SO_(4))_(3).
Answer» Solution :Atomic mass of ALUMINIUM is 27 u, of sulphur is 32 u and of oxygen is 16 u. `[Al^(3+),SO_(4)^(2-)]` Formula unit mass of `Al_(2)(SO_(4))_(3)` `= 2 XX 27) + 3(1 xx 32) + (4 xx 16)` = 54 + 3(32 + 64) = 54 + 3(96) = 54 + 288 = 342 `:.` the formula unit mass of `Al_(2)(SO_(4))_(3)` is 342 u.

Discussion

1814.	Calculatethe difference in masses of10^(3) moles each of Na atoms and Na^(+) ions( mass of an electron =9.1 xx 10^(-31) kg).
Answer» ANSWER :5.48 G

Discussion

1815.	Calculatethe concentration of a solution in volumeper centwhich contains 10 g of potassium nitrate dissolvedin 150 gof water
Answer» ANSWER :0.0625

Discussion

1816.	Calculatethe concentration of a solutionin volumeper cent made when 56 g water is mixed with 0.17 L of ethanol
Answer» Solution :VOLUMEOF WATER `=("MASS")/("density")=(56 g)/(1.0 g cm^(-3))=56 cm^(3)=56` mL volume of ethanol `=0.17 xx1000 mL = 170 mL` `therefore` concentration per centby volume=`(56)/(226)xx100=24.78%`

Discussion

1817.	Calculate the concentration in terms of mass by volume percentage of the solution containing 2.5 g potassium chloride in 50 ml of potassium chloride(KCl) Solution.
Answer» ANSWER :0.05

Discussion

1818.	Calculate the concentration interms of mass by volume pecentage of the solution containing 2.5g potassium chloride in 50 ml of potassium chloride (KCl) solution? (AS_(1))
Answer» ANSWER :0.05

Discussion

1819.	Calculate the average atomic mass of chlorine on the basis of this data : Atomic number 17, mass number 35, 37 and their ratio 3: 1.
Answer» SOLUTION :The average mass of chlorine = 35 `XX (3)/(4) + 37 xx (1)/(4)` = 26.25 + 9.25 = 35.25 The average ATOMIC mass of chlorine is 35.25 u.

Discussion

1820.	Calculate the atomic number and the mass number of the element whose nucleus contains 11 protons and 12 neutrons.
Answer» SOLUTION :ATOMIC number =11 , MASS number =23

Discussion

1821.	Calculate the atomic number of an element whose mass number is 39 and number of neutrons is 20 . Also find the name of the element.
Answer» SOLUTION :Mass Number = Atomic number + Number of NEUTRONS Atomic Number = mass number - Number of neutrons `= 39 - 20` Atomic Number = 19 ELEMENT having atomic number 19 is Potassium (K)

Discussion

1822.	Calculate mass of 6.022 xx 10^(23) number of N_(2) molecules (mass from number ) .
Answer» SOLUTION :`n = (N)/(N_(0))` `implies m = M xx (N)/(N_(0)) = 28 xx (6.022 xx 10^(23))/(6.022 xx 10^(23))` `28 xx 1 = 28` G

Discussion

1823.	Calculate mass of 3.011 xx 10^(23) number of N_(2) molecules (mass from number) .
Answer» Solution :The number of moles , n = `("given number of PARTICLES")/("Avogadro number") = (N)/(N_(0))` `= (3.011 XX 10^(23))/(6.022 xx 10^(23))` `implies m = M xx n = 14 xx (3.011 xx 10^(23))/(6.022 xx 10^(23))` `=14 xx 0.5 = 7g `

Discussion

1824.	Calculate mass of 0.5 mole of N_(2) gas (mass from mole of molecule)
Answer» Solution :mass = MOLAR mass `xx` NUMBER of MOLES `implies m = M x n = 28 xx 0.5 = 14`g

Discussion

1825.	Calculate mass of 0.5 mole of N atoms (mass from mole of atom)
Answer» Solution :MASS = molar mass `XX` NUMBER of moles `implies m = M xx n = 14 xx 0.5 = 7`G

Discussion

1826.	Calcium carbonate cannot exist in the liquid or the gaseous state .
Answer» ANSWER :T

Discussion

1827.	Calcium and Argon are example of a pair of …………………. .
Answer» ANSWER :ISOBARS

Discussion

1828.	CaCO_(3(g)) hArr CaO_((s))+CO_(2(g)). This reaction becomes irreversible because ____.
Answer» ANSWER :`CO_(2)` GASEOUS PRODUCT

Discussion

1829.	Ca^(2+) has completely filled outer shell . Justify your answer.
Answer» SOLUTION :`CA^(2+) - K - 2, L- 8 , M - 8 , N - 2` Calcium LOSES two ELECTRONS and they become `Ca^(2+)` ions . Electronic configuration: 2 , 8 , 8

Discussion

1830.	By which technique can the components of a colloid be separated ?
Answer» Solution :The components of a COLLOID can be separated by CENTRIFUGATION TECHNIQUE.

Discussion

1831.	By which process is the mixture of ammonium chloride and sand separated ?
Answer» Winnowing Centrifugation Sublimation Evaporation Answer :A::B

Discussion

1832.	By which method can potash alum be purified ?
Answer» Evaporation Crystallisation Centrifugation Filtration Answer :A::B::C::D

Discussion

1833.	Buttermilk is an example of heterogenous mixture.
Answer» ANSWER :1

Discussion

1834.	Butter is ______ type of colloid.
Answer» ANSWER :JELLY

Discussion

1835.	Butter is an example of one type of colloidal solution. Name it. Give a reason for your choice.
Answer» Solution :The colloidal solution is an example in which solid acts as the dispersion medium while liquid as the DISPERSED PHASE. It is also called gel. Reason for the choice. On pressing butter, liquid DROPS come out of it LEAVING behind a solid. This CLEARLY shows that butter is a gel.

Discussion

1836.	Butter can be separated from curd by the process of centrifugation.
Answer» ANSWER :T

Discussion

1837.	Burning of coal leads to increase in the acidity of soil. Comment on this statement.
Answer» Solution :(i) composition of coal (ii) origin of coal (iii) REACTIVITY of various COMPONENTS of coal when burnt (IV) product formed by these components (v) reactivity formed by theses components

Discussion

1838.	Burning magnesium ribbon continuously burns in nitrogen atomphere.
Answer» SOLUTION :N/A

Discussion

1839.	Bunny is a ten year old boy. His motherm Mrs. Bhatia, is having high fever today. Bunny is to go for playing a cricket match with his friends in the afternoon but his white cricket dress is very dirty. He does not know how to operate the washing machine. So, Bunny decided to wash his dirty clothes himself with hands without disturbing his mother. After washing his clothes with detergent powder, he squeezed them well to remove the maximum water out of these clothes. Bunny then kept the washed and squeezed clothers as such in the bathroom ifself for drying. He checked the wet clothes periodically. Bunny found that the wet washed clothes had not dried even after keeping for four hours in the bathroom. Just then Bunny's elder sister Anushka, who is a student of class IX, returned from school. Bunny shared his problem with her. Anushka found that Bunny had kept the washed clothes after squeezing out water as such without even spreading them. Anushka took these wet, washed clothes to the roof of their house where there was still bright sunshine. Even wind was blowing faster on the roof top. Anushka spread the wet clothes properly on the clothes line fixed on the roof of their house. Bunny was glad to find that the wet clothes had now dried in less than two hours. (a) Which process is involved in the drying of wet clothes ? Define this process (b) Apart from drying clothes, state another important use of the above process (c) Why did Anushka spread the wet clothes properly on the clothes line ? (d) Why did Anushka put the wet clothes in sunshine ? (e) How did blowing of wind help in the quick drying of wet clothes ? (f) What values are displyed by Anushka in this episode ?
Answer» Solution :(a) (i) The wet clothes dry due to the evaporation of water present in them.So, the PROCESS involved in the drying of wet clothes is 'evaporation' (ii) The process of a liquid CHANGING into vapour (or gas) even below its boiling point is called evaporation. (b) The process of evaporation is used to obtain common salt from sea-water (c) The rate of evaporation increases on increasing the surface area of the liquid (here water). Anuska spread the rapid evaporation of water present in them (which leads to quicker drying) (d) The rate of evaporation increases on increasing the temperature of liquid (here water). Anushka put the washed wet clothes in sunshine to raise their temperature for the rapid evaporation of water from them (which leads to quicker drying) (e) The rate of evaporation of a liquid (here water) increases with increasing wind speed. The blowing wind carries away the particlesof water vapour from near the wet clothes decreasing the amount of water vapour in their SURROUNDINGS. This increases the rate of evaporation of water from wet clothes (which leads to quicker drying) (f) The VARIOUS values displyed by Anushka in this episode are (i) Awareness of the process of evaporation(ii) Knowledge of the factors affecting evaporation (like surface area, temperature ADN wind speed), (iii) Application of knowledge in solving day to dayproblems, and (iv) Helping nature.

Discussion

1840.	Buckminster Fullerene contains ________ carbon atoms.
Answer» ANSWER :60

Discussion

1841.	Brass is a solution of molten copper in
Answer» Solid ZINC MOLTEN zinc Gaseous zinc Molten TIN ANSWER :B

Discussion

1842.	Brass is a
Answer» COMPOUND ELEMENT HOMOGENOUS mixture Heterogeneous mixture Answer :C

Discussion

1843.	Bose-Einstein condensate have
Answer» Very LOW KINETIC ENERGY Low kinetic energy HIGH kinetic energy HIGHEST kinetic energy Answer :A

Discussion

1844.	Bose -Einstein Condensate.
Answer» Solution :The state FORMED by cooling a gas of EXTREMELY LOW density, about one LAC the density of normal air to super low temperature is called Bose Einstein Condensate (BEC).

Discussion

1845.	Boron is a ………………
Answer» ANSWER :METALLOID

Discussion

1846.	Bond formed between a metal and non metal atom is usually (a) lonie bond (b) covalent bond (c) coordinate bond
Answer» ANSWER :A

Discussion

1847.	Boiling point
Answer» Solution :The TEMPERATURE at which a LIQUID starts boiling at the ATMOSPHERE PRESSURE is CALLED its boiling point.

Discussion

1848.	Boil about 100 ml of ground water in a vessel dryness. After all water get evaporated observe the inner wall of the vessel. Can you observe any deposits?
Answer» Answer :YES, this is the deposit of DISSOLVED SALTS present in water.

Discussion

1849.	Bleaching action of SO_2 is reversible. Justify.
Answer» Solution :SULPHUR dioxide on reaction with MOISTURE or water produce NASCENT hydrogen which HELPS in the bleaching ACTION.

Discussion

1850.	Bijal took (i) chalk powder (ii) slaked lime (iii) charcoal powder and (iv) detergent powder. She prepared four different mixtures with water and she filtered them using a filter paper. There will be no residue left after filtration in case of _____ .
Answer» CHALK powder slaked lime charcoal powder detergent powder Answer :D

Discussion

Explore topic-wise InterviewSolutions in .

Calculate the mass of water required to produce 36 g of glucose during the process of photosynthesis in plants .

Calculate the mass of the following: (i) 0.5 mole of N_(2) gas (mass from mole of molecule) (ii) 0.5 mole of N atoms (mass from mole of atom) (iii) 3.011 xx 10^(23) number of N atoms (mass from number) (iv) 6.022 xx 10^(23) number of N_(2) molecules (mass from number)

Calculate the mass of the following: (i) 0.5moles of O_(2) gas(ii) 0.5moles of O atoms (iii) 3.011xx10^(23)"atoms of O"(iv) 6.022xx10^(23)"molecules of "O_(2) (Givem: Gram atomic mass of oxygen=16g) Gram of molecular mass of oxygen (O_(2))=32g)

Calculate the mass of sodium sulphate required to prepared its 20% solution in 100g of water ?

Calculate the mass of sulphuric acid required to prepare its 20% (mass percent) solution in 100 g of water ?

Calculate the mass of magnesium deposited during the electrolysis of molten magnesium chloride by passing 193 amperes of current for 600 minutes.

Calculate the mass of a charged particle in CGS units if its charge is x coulomb and specific charge is y coulomb/g.

Calculate the mass of 12.0 xx 10^(14) atoms of hydrogen.

Calculate the mass in grams of 0.2 mole of water (H_(2)O) . ( H = 1 , O = 16)

Calculate the Molecular formula unit mass of ZnO , given atomic masses ofZn = 654 and O = 164

Calculate the formula unit masses of ZnO, Na_(2)O, K_(2)CO_(3). Given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, 0 = 16 u.

Calculate the formula unit mass of CaCl_(2).

Calculate the formula unit mass of Al_(2)(SO_(4))_(3).

Calculatethe difference in masses of10^(3) moles each of Na atoms and Na^(+) ions( mass of an electron =9.1 xx 10^(-31) kg).

Calculatethe concentration of a solution in volumeper centwhich contains 10 g of potassium nitrate dissolvedin 150 gof water

Calculatethe concentration of a solutionin volumeper cent made when 56 g water is mixed with 0.17 L of ethanol

Calculate the concentration in terms of mass by volume percentage of the solution containing 2.5 g potassium chloride in 50 ml of potassium chloride(KCl) Solution.

Calculate the concentration interms of mass by volume pecentage of the solution containing 2.5g potassium chloride in 50 ml of potassium chloride (KCl) solution? (AS_(1))

Calculate the average atomic mass of chlorine on the basis of this data : Atomic number 17, mass number 35, 37 and their ratio 3: 1.

Calculate the atomic number and the mass number of the element whose nucleus contains 11 protons and 12 neutrons.

Calculate the atomic number of an element whose mass number is 39 and number of neutrons is 20 . Also find the name of the element.

Calculate mass of 6.022 xx 10^(23) number of N_(2) molecules (mass from number ) .

Calculate mass of 3.011 xx 10^(23) number of N_(2) molecules (mass from number) .

Calculate mass of 0.5 mole of N_(2) gas (mass from mole of molecule)

Calculate mass of 0.5 mole of N atoms (mass from mole of atom)

Calcium carbonate cannot exist in the liquid or the gaseous state .

Calcium and Argon are example of a pair of …………………. .

CaCO_(3(g)) hArr CaO_((s))+CO_(2(g)). This reaction becomes irreversible because ____.

Ca^(2+) has completely filled outer shell . Justify your answer.

By which technique can the components of a colloid be separated ?

By which process is the mixture of ammonium chloride and sand separated ?

By which method can potash alum be purified ?

Buttermilk is an example of heterogenous mixture.

Butter is ______ type of colloid.

Butter is an example of one type of colloidal solution. Name it. Give a reason for your choice.

Butter can be separated from curd by the process of centrifugation.

Burning of coal leads to increase in the acidity of soil. Comment on this statement.

Burning magnesium ribbon continuously burns in nitrogen atomphere.

Buckminster Fullerene contains ________ carbon atoms.

Brass is a solution of molten copper in

Brass is a

Bose-Einstein condensate have

Bose -Einstein Condensate.

Boron is a ………………

Bond formed between a metal and non metal atom is usually (a) lonie bond (b) covalent bond (c) coordinate bond

Boiling point

Boil about 100 ml of ground water in a vessel dryness. After all water get evaporated observe the inner wall of the vessel. Can you observe any deposits?

Bleaching action of SO_2 is reversible. Justify.

Bijal took (i) chalk powder (ii) slaked lime (iii) charcoal powder and (iv) detergent powder. She prepared four different mixtures with water and she filtered them using a filter paper. There will be no residue left after filtration in case of _____ .