8881 + Interview Questions in Chemistry in Class 10 Page 175 InterviewSolution

8701.	44 g of CO_(2) contains
Answer» 2 MOLESOF oxygen atoms 1 MOLE of oxygen atoms `1.5` moles of oxygen atoms 2 moles of oxygen moleculs Answer :A

Discussion

8702.	40g of calcium was extracted from 56 g of calcium oxide (Atomic mass of Ca = 40, O = 16) (i) What mass oxygen is there is there in 56 g of calcium oxide? (ii) How many moles of oxygen atoms are there in this? (iii) How many moles of calcium atoms are there in 40 g of calcium ? (iv) What mass of calcium will be obtained from 1000 g of calcium oxide?
Answer» SOLUTION :(i) Mass of `CaO=56g` Mass of `Ca=40g` `therefore"Mass of oxygen "=56-40=16g` (ii) `("No. of moles of oxygen atom")/("Mole = mass/atomic mass")=(16)/(16)=" 1 mole"` 1 mole of oxygen atom (iii) `("No of moles of calcium")/("Mole = mass/atomic mass")=(40)/(40)="1 mole"` 1 mole of calcium atom (IV) 56 g calcium oxide gives 40 g of calcium `therefore"1000 g of calcium oxide given "=(40)/(56)xx1000` `="714.285 g of calcium "= "714.29g of calcium"`

Discussion

8703.	40% w/WCa(OH)_(2) solution has a molarity of 7.8M. Calculate the density of the solution.
Answer» `1.03` g/cc ` 1.04`g/cc `1.54`g/cc ` 1. 44 ` g/cc SOLUTION :Let the density of solution be = xg/cc Molarity = 7.8M Molecular mass of `Ca(OH)_(2) = 40 + 34 = 74` Mass of solute = 40 g Molarity = `("mass of solute")/("molecular mass of solute") XX 1000/(100/x) 3` `(.:'v = m/d)` ` 7.8 = 40/74 xx 1000/100xx x`

Discussion

8704.	40 g of sodium chloride in 100 g of water at 25^@ C forms unsaturated solution.
Answer» Solution :Correct STATEMENT: 40 g of sodium CHLORIDE in 100 g of water at `25^@ C` forms super saturated solution.

Discussion

8705.	4 g of NaOH dissolved in 100 ml solution. Molarity of the solution is
Answer» 1 M 10 M 0.1 M 4 M ANSWER :A

Discussion

8706.	36g of sodium chloride in 100 g of water at 25^@ C forms saturated solution.
Answer» ANSWER : TRUE

Discussion

8707.	36g of NaCl in 100g of water is a .......... solution.
Answer» NON AQUEOUS Unsaturated Super SATURATED Saturated SOLUTION :Saturated

Discussion

8708.	36g of NaCl in 100g of water at roor temperature forms a ................ solution.
Answer» SOLUTION :SATURATED

Discussion

8709.	3.5 litres of ethanol is present in 15 litres of aqueous solution of ethanol. Calculate volume percent of ethanol solution.
Answer» SOLUTION :Volumeofethanol( solute)= 3.5litre VOLUMEOF aqueoussolution= 15litre of thanol( solution) Volumepercentage`=(" Volume of thesolute ")/(" Volumeof the solution") XX 100` `= ( 3.5) /( 15 ) xx10` Volumepercentage`= 23.33 %`

Discussion

8710.	30gsugeris dissolvedin 170 g ofwater .Calculatethe concentrationof solutionin termsofweightpercent .
Answer» Solution :Weightpercent`=("Weightof the SOLUTE ")/("Weight of solute+ weightof solvent ") XX 100` `=( 30 )/( 30+170 ) xx 10 = 15 %`

Discussion

8711.	3.0 g of H_(2)react with 29.0 g of O_(2)yield H_(2)O. (i)Which is the limiting reagent. (ii)Calculate the maximum amount of H_(2)Othat can beformed(iii)Calculate the amount of reactant left unreacted
Answer» ANSWER :`H_(2), 26.8g H_(2)O & 5.2g O_(2)`

Discussion

8712.	2xx"Vapour" density is equal to ………………….. .
Answer» ATOMIC MASS valency RELATIVE MOLECULAR mass atomic number Solution :relative molecular mass

Discussion

8713.	2xxVapourdensityis equalto
Answer» Grammolecularweight Relativemolecular WEIGHT ATOMICWEIGHT Gramatomicweight ANSWER :B

Discussion

8714.	2SO_(2(g)) + O_(2(g)) hArr 2SO_(3(g)) + QKJ In the above reaction, how can the yield of product be increased without increasing the pressure ?
Answer» by increasing temperature by decreasing temperature by increasing TH VOLUME of the reaction vessel by the ADDITION of the catalyst Answer :B

Discussion

8715.	2SO_2+O_2 to 2SO_3 represents an important stage in the Industrial Preparation of Sulphuric acid. Which is the catalyst used in this process ?
Answer» ANSWER :VANADIUM PENTOXIDE

Discussion

8716.	2SO_2+O_2 to 2SO_3 represents an important stage in the Industrial Preparation of Sulphuric acid. How do the following changes influence the forward reaction ? i) More oxygen ( O_2 ) is added. ii) Pressure is decreased.
Answer» ANSWER :i) SPEED of FORWARD REACTION iincreases.Ii) Speed of forward reaction DECREASES

Discussion

8717.	2SO_2+O_2 to 2SO_3 represents an important stage in the Industrial Preparation of Sulphuric acid. By what name is the Industrial Preparation of Sulphuric acid known as?
Answer» ANSWER :CONTACT PROCESS

Discussion

8718.	2Pb(NO_(3))_(2) to 2PbO+nA+O_(2). What is nA in the given reaction ?
Answer» 4NO `4NO_(2)` `2PbNO_(2)` `NO_(2)` ANSWER :B

Discussion

8719.	2N represents two
Answer» MOLECULES of NITROGEN ATOMS of nitrogen compounds of nitrogen ions of nitrogen Solution : atoms of nitrogen

Discussion

8720.	2KCiO_(3)to2KCl+3O_(2). This reaction is
Answer» combination Double DISPLACEMENT DECOMPOSITION displacement ANSWER :C

Discussion

8721.	2g of ferrous sulphate crystals are heated in a dry tude. Name the type of chemical reaction taking place.
Answer» SOLUTION :DECOMPOSITION REACTION.

Discussion

8722.	2g of ferrous sulphate crystals are heated in a dry tude. List any two observations.
Answer» Solution :Green COLOUR of `FeSO_(4)` disappears and reddish brown SOLID is formed. Decomposition reaction. `2FeSO_(4)(s) overset("heat") to Fe_(2)O_(3)(s)+SO_(2)(g)+SO_(3)(g)`.

Discussion

8723.	2g of ferrous sulphate crystals are heated in a boiling tube. (i) State the colour of ferrous sulphate crystals both before heating and after heating. (ii) Name the gases produced during heating . (iii) Write the chemical equation for the reaction .
Answer» SOLUTION :(i) Before heating : Pale GREEN After heating : BROWN or reddish brown. (ii) `SO_(2) and SO_(3)` (iii) `2FeSO_(4)(S) overset("Heat") rarr Fe_(2)O_(3)(S)+SO_(2)(G)+SO_(3)(g)`

Discussion

8724.	2g ferroussulphate crystal are heated in a dry boiling tube. (i) List any two observations. (ii) Name the type of chemical reaction taking place. (iii) Write the chemical equation of the reaction.
Answer» Solution :(i) Before heating, it is pale green . After heating it is brown or reddish brown. TWO OBSERVATIONS are : (a) Change in state and colour (b) Evolution of gas. (ii) Decomposition reaction. (iii) `2FeSO_(4)(s) overset ("Heat")rarr Fe_(2)O_(3)(s)+SO_(2)G+SO_(3)(g)`

Discussion

8725.	2FeCl_(3)+SnCl_(2)to2FeCl_(2)+SnCl_(4) is an example of
Answer» NON redox reaction double displacement reaction redox reaction None of these Solution :The reaction is a redox reaction. Fe CHANGES its VALENCE from +3 to +2 while SN changes its valance from +2 to +4

Discussion

8726.	2Cu+O_(2)to2CuO. This reaction is
Answer» OXIDATION REDUCTION DISPLACEMENT DECOMPOSITION ANSWER :A

Discussion

8727.	2AlCl_3 represents
Answer» TWO ATOMS of Aluminium Chloride two molecules of Aluminium Chloride three atoms of Chlorine two atoms of Aluminium Solution :`2AlCl_3` REPRESENTS two molecules of `AICI_3`3

Discussion

8728.	2Al(OH)_2 overset(1000^(@)C)to __________ +3H_(2)O.
Answer» SOLUTION :`Al_2O_3`

Discussion

8729.	2AgNO_(3)(aq)+Zn(s) to ______+ ______
Answer» SOLUTION :`Zn(NO_(3))_(2) (aq ) +2Ag(s)`

Discussion

8730.	25 ml of 3.0 M HCl are mixed with 75 mL 0f 4.0 M HCl. If the volumes are additive, the molarity of the final mixture will be.
Answer» ANSWER : 3.75 M

Discussion

8731.	2.5 g of CaCO_(3)was placed in 50 ml of a solution of HCl.1.05 g of CaCO_(3)was leftafter the reaction. Calculate: the Molarity of HCl
Answer» ANSWER : 0.58 M

Discussion

8732.	2.5 g of CaCO_(3)was placed in 50 ml of a solution of HCl.1.05 g of CaCO_(3)was leftafter the reaction. Calculate: the weight of HCl per litre
Answer» ANSWER : 21.17 G

Discussion

8733.	23 g of NO_(2) contains same number of molecules as
Answer» 8 G of oxygen 28g of carbon monoxide 16g of `SO_(2)` 22g of `CO_(2)` ANSWER :D

Discussion

8734.	20g of NaCl in 100g of water is ........ solution.
Answer» SOLUTION :UNSATURATED

Discussion

8735.	20 cc of a hydrocarbon, on complete combustion, gave 80 cc of CO_(2) and " ccof " H_(2)O at STP. The empirical formula of that compound is
Answer» `C_(2)H_(5)` `C_(2)H_(6)` `C_(3)H_(8)` `C_(4)H_(10)` ANSWER :A

Discussion

8736.	2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.
Answer» SOLUTION :`Zn + 2NaOH rarr underset("zincate")underset("Sodium")Na_2ZnO_2+H_2` The gas is detected by bringing a burning CANDLE near the soap BUBBLES. A pop sound is heard. Hydrogen gas will be evolved in this CASE also

Discussion

8737.	2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed a gas ecolces which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of an acid. Or The pH of a salt used to amke tasty and crispy pakoras is 8.4. Identify the salt and write a chemical equation for its formation. List its two uses.
Answer» Solution :Hydrogen gas is evolved in the reaction. `Zn(s)+2NAOH(aq)tounderset("Sodium Zincate")(Na_(2)ZnO_(2))(aq)+H_(2)(g)` Candle FLAME is brought in contact with the bubbles of hydrogen after PASSING through the soap solution. The gas burns brightly with popping sound. Same gas will EVOLVE when the metal reacts with dilute solution of acid such as HCl or `H_(2)SO_(4).` Or The salt with pH 8.4 is sodium hydrogen carbonate. For the details, CONSULT section 2.14.

Discussion

8738.	2 ml of NaOH solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. (i) Write the equation of the chemical reaction involved and the test to detect the gas. (ii) Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.
Answer» Solution :(i) `Zn + 2NaOH rarr Na_(2)ZnO_(2) + H_(2)` The gas can be detected by bringing a burning SPLINTER near the mouth of the TEST TUBE. If the gas burns with a BLUE flame and produces a pop sound. The gas evolved is Hydrogen. (II) `Zn+HCl("dil") rarr ZnCl_(2) + H_(2)` `H_(2)` gas is evolved in this reaction too.

Discussion

8739.	2 g of potassium sulphate was dissolved in 12.5 ml of water. On cooling, the first crystals appeared at 60^@ C. What is the solubility of potassium sulphate in water at 60^@ C?
Answer» Solution :12.5 ml of WATER weighs 12.5 g. In 12.5 g of water, the AMOUNT of potassium SULPHATE dissolved is 2 g. In 1 g of water, amount of potassium sulphate dissolved is 2/12.5 g. Hence in 100 g of water, the amount of potassium sulphate dissolved is`(2 xx100)// 12.5 = 16 g.` The solubility of potassium sulphate in water at 60°C is 16 g.

Discussion

8740.	2 g lead nitrate powder is taken in a boiling tube . The boiling tube is heated over a flame. Now answer the following : (i) State the colour of the fumes evolved and the residue left. (ii) Name the type of chemical reaction that has taken place, stating its balanced equation.
Answer» Solution :(i) BROWN FUMES , WHITE residue. (II) Decomposition reaction `2Pb(NO_(3))_(2)rarr2PbO+4NO_(2)+O_(2)`

Discussion

8741.	{:(1.,"Sodium silicate",(a),"glow to the clothes"),(2.,"Fluorescent whitening agent",(b),"removal of certain stains"),(3.,"Sodium perborate",(c),"prevent the caking of the detergent powder"),(4.,"Sodium sulphate",(d),"prevents corrosion"):}
Answer» ANSWER :d, a, B, C

Discussion

8742.	{:(1.,"Methylated spirit",(a),"Ethanal + water"),(2.,"Power alcohol",(b),"Ethanol + pyridine"),(3.,"Denatured spirit",(c),"Ethanol + petrol"),(4.,"Rectified spirit",(d),"Ethanol + methanol"):}
Answer» ANSWER :d, C, B, a

Discussion

8743.	1L of a gas at STP weighs 1.97g. What is molecular mass ?
Answer» ANSWER :`44.128 "G MOL"^(-1)`

Discussion

8744.	{:(1.,"Ethene",(a),C_(3)H_(4)),(2.,"Ethane",(b),C_(3)H_(6)),(3.,"Propyne",(c),C_(2)H_(4)),(4.,"Propene",(d),C_(2)H_(6)):}
Answer» ANSWER :C, d, a, B

Discussion

8745.	{:(1.,C_(n)H_(2n+2),(a),"Alkene"),(2.,C_(n)H_(2n),(b),"Alcohol"),(3.,C_(n)H_(2n-2),(c),"Alkane"),(4.,ROH,(d),"Alkyne"):}
Answer» ANSWER :C, a, d, B

Discussion

8746.	{:(1.,CH_(3)-CH_(2)OH,(a),"Ethanal"),(2.,CH_(3)-COOH,(b),"Ethanol"),(3.,CH_(3)-CHO,(c),"Propanone"),(4.,CH_(3)-underset(O)underset(\|\|)(C)-CH_(3),(d),"Ethanoic acid"):}
Answer» ANSWER :B, d, a, C

Discussion

8747.	{:(1.,CH_(3)OH,(a),"Dimethyl Ketone"),(2.,CH_(3)CHO,(b),"Acetic acid"),(3.,CH_(3)COCH_(3),(c),"Acetaldehyde"),(4.,CH_(3)COOH,(d),"Methyl alcohol"):}
Answer» ANSWER :d, C, a, B

Discussion

8748.	{:(1.,"Alcohol",(a),(##FM_SCI_X_C11_E02_088_Q01##)),(2.,"Aldehyde",(b),- COOH),(3.,"Ketone",(c),- CHO),(4.,"Carboxylic acid",(d),- HO):}
Answer» ANSWER :d, C, a, B

Discussion

8749.	{:(1.,"Acyclic compounds",(a),"Cyclobutene"),(2.,"Alicyclic compounds",(b),"Ethene"),(3.,"Homocyclic aromatic compounds",(c),"Pydridine"),(4.,"Heterocyclic compounds",(d),"Benzene"):}
Answer» ANSWER :B, a, d, C

Discussion

8750.	State whether the statement is true or false.18 g of water vapour and 18 g of ice willcontain the same number of molecules.
Answer» ANSWER :T

Discussion

Explore topic-wise InterviewSolutions in .

44 g of CO_(2) contains

40% w/WCa(OH)_(2) solution has a molarity of 7.8M. Calculate the density of the solution.

40 g of sodium chloride in 100 g of water at 25^@ C forms unsaturated solution.

4 g of NaOH dissolved in 100 ml solution. Molarity of the solution is

36g of sodium chloride in 100 g of water at 25^@ C forms saturated solution.

36g of NaCl in 100g of water is a .......... solution.

36g of NaCl in 100g of water at roor temperature forms a ................ solution.

3.5 litres of ethanol is present in 15 litres of aqueous solution of ethanol. Calculate volume percent of ethanol solution.

30gsugeris dissolvedin 170 g ofwater .Calculatethe concentrationof solutionin termsofweightpercent .

3.0 g of H_(2)react with 29.0 g of O_(2)yield H_(2)O. (i)Which is the limiting reagent. (ii)Calculate the maximum amount of H_(2)Othat can beformed(iii)Calculate the amount of reactant left unreacted

2xx"Vapour" density is equal to ………………….. .

2xxVapourdensityis equalto

2SO_(2(g)) + O_(2(g)) hArr 2SO_(3(g)) + QKJ In the above reaction, how can the yield of product be increased without increasing the pressure ?

2SO_2+O_2 to 2SO_3 represents an important stage in the Industrial Preparation of Sulphuric acid. Which is the catalyst used in this process ?

2SO_2+O_2 to 2SO_3 represents an important stage in the Industrial Preparation of Sulphuric acid. How do the following changes influence the forward reaction ? i) More oxygen ( O_2 ) is added. ii) Pressure is decreased.

2SO_2+O_2 to 2SO_3 represents an important stage in the Industrial Preparation of Sulphuric acid. By what name is the Industrial Preparation of Sulphuric acid known as?

2Pb(NO_(3))_(2) to 2PbO+nA+O_(2). What is nA in the given reaction ?

2N represents two

2KCiO_(3)to2KCl+3O_(2). This reaction is

2g of ferrous sulphate crystals are heated in a dry tude. Name the type of chemical reaction taking place.

2g of ferrous sulphate crystals are heated in a dry tude. List any two observations.

2g of ferrous sulphate crystals are heated in a boiling tube. (i) State the colour of ferrous sulphate crystals both before heating and after heating. (ii) Name the gases produced during heating . (iii) Write the chemical equation for the reaction .

2g ferroussulphate crystal are heated in a dry boiling tube. (i) List any two observations. (ii) Name the type of chemical reaction taking place. (iii) Write the chemical equation of the reaction.

2FeCl_(3)+SnCl_(2)to2FeCl_(2)+SnCl_(4) is an example of

2Cu+O_(2)to2CuO. This reaction is

2AlCl_3 represents

2Al(OH)_2 overset(1000^(@)C)to __________ +3H_(2)O.

2AgNO_(3)(aq)+Zn(s) to ______+ ______

25 ml of 3.0 M HCl are mixed with 75 mL 0f 4.0 M HCl. If the volumes are additive, the molarity of the final mixture will be.

2.5 g of CaCO_(3)was placed in 50 ml of a solution of HCl.1.05 g of CaCO_(3)was leftafter the reaction. Calculate: the Molarity of HCl

2.5 g of CaCO_(3)was placed in 50 ml of a solution of HCl.1.05 g of CaCO_(3)was leftafter the reaction. Calculate: the weight of HCl per litre

23 g of NO_(2) contains same number of molecules as

20g of NaCl in 100g of water is ........ solution.

20 cc of a hydrocarbon, on complete combustion, gave 80 cc of CO_(2) and " ccof " H_(2)O at STP. The empirical formula of that compound is

2 g of potassium sulphate was dissolved in 12.5 ml of water. On cooling, the first crystals appeared at 60^@ C. What is the solubility of potassium sulphate in water at 60^@ C?

2 g lead nitrate powder is taken in a boiling tube . The boiling tube is heated over a flame. Now answer the following : (i) State the colour of the fumes evolved and the residue left. (ii) Name the type of chemical reaction that has taken place, stating its balanced equation.

{:(1.,"Sodium silicate",(a),"glow to the clothes"),(2.,"Fluorescent whitening agent",(b),"removal of certain stains"),(3.,"Sodium perborate",(c),"prevent the caking of the detergent powder"),(4.,"Sodium sulphate",(d),"prevents corrosion"):}

{:(1.,"Methylated spirit",(a),"Ethanal + water"),(2.,"Power alcohol",(b),"Ethanol + pyridine"),(3.,"Denatured spirit",(c),"Ethanol + petrol"),(4.,"Rectified spirit",(d),"Ethanol + methanol"):}

1L of a gas at STP weighs 1.97g. What is molecular mass ?

{:(1.,"Ethene",(a),C_(3)H_(4)),(2.,"Ethane",(b),C_(3)H_(6)),(3.,"Propyne",(c),C_(2)H_(4)),(4.,"Propene",(d),C_(2)H_(6)):}

{:(1.,C_(n)H_(2n+2),(a),"Alkene"),(2.,C_(n)H_(2n),(b),"Alcohol"),(3.,C_(n)H_(2n-2),(c),"Alkane"),(4.,ROH,(d),"Alkyne"):}

{:(1.,CH_(3)-CH_(2)OH,(a),"Ethanal"),(2.,CH_(3)-COOH,(b),"Ethanol"),(3.,CH_(3)-CHO,(c),"Propanone"),(4.,CH_(3)-underset(O)underset(||)(C)-CH_(3),(d),"Ethanoic acid"):}

{:(1.,CH_(3)OH,(a),"Dimethyl Ketone"),(2.,CH_(3)CHO,(b),"Acetic acid"),(3.,CH_(3)COCH_(3),(c),"Acetaldehyde"),(4.,CH_(3)COOH,(d),"Methyl alcohol"):}

{:(1.,"Alcohol",(a),(##FM_SCI_X_C11_E02_088_Q01##)),(2.,"Aldehyde",(b),- COOH),(3.,"Ketone",(c),- CHO),(4.,"Carboxylic acid",(d),- HO):}

{:(1.,"Acyclic compounds",(a),"Cyclobutene"),(2.,"Alicyclic compounds",(b),"Ethene"),(3.,"Homocyclic aromatic compounds",(c),"Pydridine"),(4.,"Heterocyclic compounds",(d),"Benzene"):}

State whether the statement is true or false.18 g of water vapour and 18 g of ice willcontain the same number of molecules.

2AgNO_(3)(aq)+Zn(s) to +