Solving ICSE Class 10 Chemistry Previous Year Question Papers ICSE Class 10 Chemistry Question Paper 2013 is the best way to boost your preparation for the board exams.
ICSE Class 10 Chemistry Question Paper 2013 Solved
Time: 1½ hour
Maximum Marks: 80
General Instructions:
- Answer to this Paper must he written on the paper provided separately.
- You will not be allowed to write during the first 15 minutes.
- This time is to be spent in reading the Question Paper.
- The time given at the head of this paper is the time allowed for writing the answers.
- Section I is compulsory. Attempt any four questions from Section II.
- The intended marks for questions or parts of questions are given in brackets [ ].
Section I (40 Marks)
Attempt all questions from this Section.
Question 1.(a) From the list given below, select the word(s) required to correctly complete blanks (i) to (v) in the following passage. The words from the list are to be used only once. Write the answers as (a) (i), (ii), (iii) and so on. Do not copy the passage.
[ammonia, ammonium, carbonate, carbon dioxide, hydrogen, hydronium, hydroxide,precipitate, salt, water]:
(i) A solution M turns blue litmus red, so it must contain (i) ………………… ions; another solution O turns red litmus blue and hence, must contain (ii) …………………. ions.
(ii) When solutions M and O are mixed together, the products will be (iii) …………………. and (iv) ………………….
(iii) If a piece of magnesium was put into a solution M, (v) …………………. gas would be evolved. [5]
Answer:
(i) hydronium,
(ii) hydroxide
(iii) salt,
(iv) water
(v) hydrogen
(b) Identify the gas evolved in the following reactions when :
(i) sodium propionate is heated with soda lime.
(ii) potassium sulphite is treated with dilute hydrochloric acid.
(iii) sulphur is treated with concentrated nitric acid.
(iv) a few crystals of KNOa are heated in a hard glass test tube.
(v) concentrated hydrochloric acid is made to react with manganese dioxide. (5)
Answer:
(i) Ethane
(ii) Sulphur dioxide
(iii) Nitrogen dioxide
(iv) Oxygen
(v) Chlorine
(c) State one appropriate observation for each of the following:
(i) Concentrated sulphuric acid is added drop wise to a crystal of hydrated copper sulphate.
(ii) Copper sulphide is treated with dilute hydrochloric acid.
(iii) Excess of chlorine gas is reacted with ammonia gas.
(iv) A few drops of dilute hydrochloric acid are added to silver nitrate solution, followed by addition of ammonium hydroxide solution.
(v) Electricity is passed through molten lead bromide. (5)
Answer:
(i) The blue crystals (of CuSO4.5H2O) change to a white powder (of CuSO4).
(ii) A gas having rotten egg smell (H2S) is released which turns lead acetate paper black.
(iii) A yellow explosive liquid (nitrogen trichloride) is formed.
(iv) A curdy white precipitate (of AgCl) is formed which is insoluble in HNO3 but soluble in NH4OH.
(v) A silvery white metal (of Pb) is deposited at cathode.
(d) Give suitable chemical terms for the following :
(i) A bond formed by a shared pair of electrons with both electrons coming from the same atom.
(ii) A salt formed by incomplete neutralisation of an acid by a base.
(iii) A reaction in which hydrogen of an alkane is replaced by a halogen.
(iv) A definite number of water molecules bound to some salts.
(v) The process in which a substance absorbs moisture from the atmosphere air to become moist, and ultimately dissolves in the absorbed water.
Answer:
(i) Coordinate bond
(ii) Acidic salt
(iii) Subsitution reaction
(iv) Water of crystallisation
(v) Deliquescence
(e) Give a chemical test to distinguish between the following pairs of compounds : [5]
(i) Sodium chloride solution and sodium nitrate solution.
Answer:
Add AgNO3 solution to both the solutions of salt in water.
NaCl solution – curdy white precipitates of AgCl are formed which are insoluble in HNO3 but soluble in NH4OH.
NaNO3 solution – no reaction.
(ii) Hydrogen chloride gas and hydrogen sulphide gas.
Answer:
A rod dipped in NH4OH is brought near gas jars containing HCl gas and H2S gas respectively.
HCl gas – dense white fumes of NH4Cl are seen.
H2S gas – no reaction.
(iii) Ethene gas and ethane gas.
Answer:
Add a few drops of bromine solution in carbon tetrachloride to the given hydrocarbons.
Ethene gas-the reddish brown colour of bromine solution gets decolourized.
Ethane gas-no change in colour.
(iv) Calcium nitrate solution and zinc nitrate solution.
Answer:
Add NH4OH to both the salt solutions.
Ca(NO3)2 – White ppts. of Ca(OH)2 are seen.
Zn(NO3)2 – gelatinous white ppts. of Zn(OH)2 are seen which dissolves in excess of NH4OH.
(v) Carbon dioxide gas and sulphur dioxide gas.
Answer:
Pass both the gases through excess of limewater.
CO2 gas-turns limewater milky, and even in excess of limewater, the milkiness remains.
SO2 gas-turns limewater milky, but on passage through excess of limewater, milkiness disappears.
(f) Choose the most appropriate answer from the following options :
(i) Among the period 2 elements, the element which has high electron affinity is
(a) Lithium
(b) Carbon
(c) Chlorine
(d) Fluorine
Answer:
(d) Fluorine has highest electron affinity
(ii) Among the following compounds identify the compound that has all three bonds (ionic, covalent and coordinate bond).
(a) Ammonia
(b) Ammonium chloride
(c) Sodium hydroxide
(d) Calcium chloride
Answer:
(b) Ammonium chloride has all the three electronic bonds
(iii) Identify the statement that is incorrect about alkanes :
(a) They are hydrocarbons.
(b) There is single covalent bond between carbon and hydrogen
(c) They can undergo both substitution as well as addition reactions
(d) On complete combustion they produce carbon dioxide and water.
Answer:
(c) They can undergo both substitution as well as addition reactions.
(iv) Which of these will act as non-electrolyte ?
(a) Liquid carbon tetrachloride
(b) Acetic acid
(c) Sodium hydroxide aqueous solution acid,
(d) Potassium chloride aqu. solution.
Answer:
(a) Liquid carbon tetrachloride is non-electrolyte
(v) Which one of the following will not produce an acid when made to react with water ?
(a) Carbon monoxide
(b) Carbon dioxide
(c) Nitrogen dioxide
(d) Sulphuric trioxide.
Answer:
(a) Carbon monoxide gas
(vi) Identify the metallic oxide which is amphoteric in nature :
(a) Calcium oxide
(b) Barium oxide
(c) Zinc oxide
(d) Copper (II) oxide
Answer:
(c) Zinc oxide is an amphoteric oxide
(vii) In the given equation identify the role played by concentrated sulphuric acid
S + 2H2SO4 → 3 SO2 + 2H2O:
(a) Non-volatile acid
(b) Oxidising agent
(c)Dehydrating agent
(d) none of these
Answer:
(b) Concentrated sulphuric acid acts as oxidising agent
(viii) Nitrogen gas can be obtained by heating :
(a) Ammonium nitrate
(b) Ammonium nitrite
(c) Magnesium nitric
(d) Ammonium chloride
Answer:
(b) Ammonium nitrite
(ix) Which of the following is not a typical property of an ionic compound ?
(a) High melting point
(b) Conducts electricity in the molten and in the aqueous solution state
(c) They are insoluble in water
(d) They exist as oppositely charged ions even in the solid state.
Answer:
(c) Ionic compounds are generally insoluble in water
(x) The metals zinc and tin are present in the alloy: (10)
(a) Solder
(b) Brass
(c) Bronze
(d) Duralumin.
Ans.
(c) Bronze
(g) Solve the following :
(i) What volume of oxygen is required to burn completely 90 dm3 of butane under similar conditions of temperature and pressure ? 2C4H10 + 13O2 → 8CO2 + 10H2O
Answer:
2C4H10 + 13O2 → 8CO2 + 10H2O
2 vol. of C4H10 → 13 vol. of O2
1 vol. of C4H10 → \(\frac{13}{2}\) vol. of O2
90 dm3 of C4H10 → \(\frac{13}{2}\) × 90
⇒ 585 dm3 of O2
(ii) The vapour density of a gas is 8. What would be the volume occupied by 24.0 g of the gas at STP ? (2)
Answer:
VD = 8
R.M.W. = 2 × VD ⇒ 2 × 8 ⇒ 16 g
∴ 16 g of gas ⇒ 22.4 l
1 g of gas ⇒ \(\frac{22.4}{16}\)
24 g of gas ⇒ \(\frac{22.4}{16}\) × 24
⇒ 33.6 l
(iii) A vessel contains X number of molecules of hydrogen gas at a certain temperature and pressure, flow many molecules of nitrogen gas would be present in the same vessel under the same conditions of temperature and pressure ? (1)
Answer:
No. of H2 molecules in the vessel = X
∴ by Avogadro’s law, no. of N2 molecules in the same vessel under similar conditions of temperature and pressure = X
Section – II (40 Marks)
Attempt any four questions from this Section
Question 2.
(a)
- In this table H does not represent hydrogen.
- Some elements arc given in their own symbol and position in the periodic table.
- While others are shown with a letter.
With reference to the table answer the following questions.
(i) Identify the most electronegative element. (1)
(ii) Identify the most reactive element of group 1. (1)
(iii) Identify the element from period 3 with least atomic size. (1)
(iv) How many valence electrons are present in Q ? (1)
(v) Which element from group 2 would have the least ionization energy ? (1)
(vi) Identify the noble gas of the fourth period. (1)
(vii) In the compound between A and H what type of bond would be formed and give the molecular formula for the same. (2)
Answer:
(i) J (fluorine)
(ii) R (potassium)
(iii) M (chlorine)
(iv) 5 valence e–
(v) T (calcium)
(vi) Y (krypton)
(vii) ionic, (A2H)
(b) Compare the compounds carbon tetrachloride and sodium chloride with regard to solubility in water and electrical conductivity. (2)
Answer:
| CCl4 | NaCl | |
| Solubility in water: Electrical conductivity: | Insoluble in water Bad conductor of electricity, molten or aqueous state. | Soluble in water
Good conductor of electricity in |
Question 3.
(a) Choosing the substances from the list given below, write balanced chemical equations for the reactions which would be used in the laboratory to obtain the following salts : [4]
| Dilute Sulphuric acid | Copper | Copper (II) carbonate |
| Iron | Sodium carbonate | |
| Sodium | Sodium chloride | |
| Zinc nitrate |
(i) Sodium sulphate
(ii) Zinc carbonate
(iii) Copper (II) sulphate
(iv) Iron (II) sulphate.
Answer:
(i) 2NaCl + H2SO4 (dil.) → Na2SO4 + 2HCl
(ii) Zn(NO3)2 + Na2CO3 → ZnCO3 + 2NaNO3
(iii) CuCO3 + H2SO4 (dil.) → CuSO4 + H2O + CO2
(iv) Fe + H2SO4 (dil.) → FeSO4 + H2
(b) State two relevant observations for each of the following :
(i) Ammonium hydroxide solution is added to copper (II) nitrate solution in small quantities and then in excess.
(ii) Ammonium hydroxide solution is added to zinc nitrate solution in minimum quantities and then in excess.
(iii) Lead nitrate crystals are heated in a hard glass test tube. [6]
Answer:
(b) (i) (1) When NH4OH is added in small quantity, pale blue ppt. (of Cu (OH)2) are formed.
(2) When NH4OH is added in excess, the ppt. dissolve to form a complex to give an inky blue solution.
(ii) (1) When NH4OH is added in small quantity, gelatinous white ppt. (of Zn (OH)2) are formed.
(2) When NH4OH is added in excess, the ppt. dissolve to form a complex, to give clear solution.
(iii) (1) A yellow coloured compound (PbO) is formed which fuses with the walls of the test tube.
(2) A reddish brown gas (NO2) is evolved.
Question 4.
(a) Copper sulphate solution is electrolysed using copper electrodes.
Study the diagram given below and answer the question that follows:
(i) Which electrode to your left or right is known as the oxidising electrode and why? (2)
Answer:
Left (anode ; + ve terminal of the battery). It is called the oxidising electrode as anions give their electrons to anode, and thus undergo oxidation.
(ii) Write the equation representing the reaction that occurs. (1)
Answer:
At cathode (-ve terminal of battery ; rich in e–)
Cu2+ + 2e– → Cu
At anode (+ ve terminal of battery ; deficient in e~)
Cu – 2e– → Cu2+
(iii) State two appropriate observations for the above electrolysis reaction. (2)
Answer:
(1) Blue colour of CuSO4 solution does riot fade.
(2) Anode withers aways. Loss in weight of anode is always equal to gain in weight of cathode.
(b)
| X | Y | |
| Normal Electronic Configuration | 2, 8, 7 | 2, 8, 2 |
| Nature of oxide | Dissolves in water and turns blue litmus red | Very low solubility in water. Dissolves in hydrochloric acid |
| Tendency for oxidising and reducing reactions | Tends to oxidise elements and compounds | Tends to act as a reducing agent |
| Electrical and Thermal conductivity | Very poor electrical conductor; Poor thermal conductivity | Good Electrical conductor Good Thermal conductor |
| Tendency to form alloys and amalgums | No tendency to form alloys | Forms alloys |
Using the information above, complete the following :
(i) ……………… is the metallic element.
(ii) Metal atoms tend to have a maximum of ……………… electrons in the outermost energy level.
(iii) Non-metallic elements tend to form ……………… oxides while metals tend to form ……………… oxides.
(iv) Non-metallic elements tend to be ……………… conductors of heat and electricity.
(v) Metals tend to ……………… electrons and act as ……………… agents in their reactions with elements and compounds. (5)
Answer:
(i) Y,
(ii) Three
(iii) acidic, basic
(iv) bad
(v) lose, reducing
Question 5.
a. Give balanced equations for each of the following : (4)
(i) Reduction of hot Copper (II) oxide to copper using ammonia gas.
Answer:
(i) 3CuO + 2NH3 → 3Cu + 3H2O + N2
(ii) Oxidation of carbon with concentrated nitric acid.
Answer:
C + 4HN3 → CO2 + 2H2O+ 4NO2
(iii) Dehydration of concentrated sulphuric acid with sugar crystals
Answer:
(b) Copy and complete the following table relating to important industrial process:
Answer:
(c) The following questions relate to the extraction of aluminium by electrolysis :
(i) Name the other aluminium containing compound added to alumina and state its significance.
Answer:
Cryolite (Na3AlF6)
- It acts as a solvent.
- It lowers the fusion temperature from 2050°C to 950°C
(ii) Give the equation for the reaction that takes place at the cathode.
Answer:
At cathode (-ive terminal of battery ; rich in e–)
Al+3 + 3e– → Al
(iii) Explain why is it necessary to renew the anode periodically.
Answer:
At anode, O2 is evolved, which reacts with carbon anode to form CO and futher forms CO2.
Question 6.
(a) Give balanced equations for the laboratory preparations of the following organic compounds : (4)
(i) A saturated hydrocarbon from iodomethane.
Answer:
(ii) An unsaturated hydrocarbon from an alcohol.
Answer:
(iii) An unsaturated hydrocarbon from calcium carbide.
Answer:
CaC2 + 2H2O → Ca(OH)2 + C2H2
(iv) An alcohol from ethyl bromide.
Answer:
C2H5Br + KOH → KBr + C2H5OH
(b) Give the structural formulae for the following : (3)
(i) An isomer of n-butane.
Answer:
(ii) 2-propanol.
Answer:
(iii) Diethyl ether.
Answer:
C2H5 – O – C2H5 (Diethyl ether)
(c) Give reasons for the following : [3]
(i) Methane does not undergo addition reactions, but ethene docs.
Answer:
Methane does not undergo addition reactions, but ethene does because methane is a saturated compound but ethene is an unsaturated hydrocarbon.
(ii) Gthync is more reactive than ethane.
Answer:
Ethyne is more reactive than ethane because ethyne has triple bond but ethane has single bond. Ethyne is unstable, so it reacts with other compounds in order to become stable.
(iii) Hydrocarbons arc excellent fuels.
Answer:
Hydrocarbons are excellent fuels because they are inflammable.
Question 7.
(a) O2 is evolved by heating KClO3 using MnO2 as a catalyst
2KClO3 → 2KCl + 3O2
(i) Calculate the mass of KClO3 required to produce 6.72 litre of 02 at STP. [atomic masses of K = 39, Cl = 35.5, O = 16] (2)
Answer:
To produce 67.2 L of O2 → 225 g of KClO3 is used
To produce 1 L of O2 → \(\frac{225}{67.2}\) of KClO3 is used
To produce 6.72 L of O2 → \(\frac{225}{67.2} \times \frac{67.2}{100}\) × 10 ⇒ 22.5 g
(ii) Calculate the number of moles of oxygen present in the above volume and also the number of molecules. (2)
Answer:
(iii) Calculate the volume occupied by 0.01 mole of CO2 at STP. (1)
Answer:
1 mole occupies → 22.4 L of volume of CO2
0.01 mole occupies → \(\frac{224}{10} \times \frac{1}{100}=\frac{224}{1000}\) ⇒ 0.224 L.
(b) Identify the following substances which are underlined :
(i) An alkaline gas which produces dense white fumes when reacted with hydrogen chloride gas.
Answer:
Ammonia
(ii) An acid which is present in vinegar.
Answer:
Acetic acid
(iii) A gas which does not conduct electricity in the liquid state but conducts electricity when dissolved in water.
Answer:
Hydrogen chloride
(iv) A dilute mineral acid which forms a white precipitate when treated with barium chloride solution.
Answer:
Dilute sulphuric acid.
(v) The element which has the highest ionization potential.
Answer:
Fluorine.