Students should refer to ICSE Class 10 Chemistry Question Paper solved Set A given below which will help them to prepare for the upcoming ICSE Chemistry exams. Students should read ICSE Chemistry Class 10 Books to make sure they are completely prepared and should also refer to ICSE Class 10 Chemistry Solutions to understand all questions and their answers.
ICSE Class 10 Chemistry Question Paper solved Set A
PAPER 2 (CHEMISTRY)
(Two hours)
Answers to this Paper must be 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 [ ].
ICSE Class 10 Chemistry Question Paper solved Set A
SECTION – I (40 MARKS)
(Attempt all questions from this Section)
Question 1.
(a) Fill in the blanks from the choices given in brackets. [5]
(i) The energy required to remove an electron from a neutral isolated gaseous atom and convert it into a positively charged gaseous ion is called .
(electron affinity, ionisation potential, electronegativity)
(ii) The compound that does not have a lone pair of electrons is . (water,ammonia, carbon tetrachloride)
(iii) When a metallic oxide is dissolved in water, the solution formed has a high concentration of ions. (H+, H3O+, OH–)
(iv) Potassium sulphite on reacting with hydrochloric acid releases gas.
(Cl2, SO2, H2S)
(v) The compound formed when ethene reacts with Hydrogen is . (CH4, C2H6, C3H8)
Ans. (i) Ionisation potential
(ii) Carbon tetrachloride or CCl4
(iii) OH–
(iv) SO2
(v) C2H6
(b) Choose the correct answer from the options given below : [5]
(i) A chloride which forms a precipitate that is soluble in excess of ammonium hydroxide, is:
(A) Calcium chloride
(B) Ferrous chloride
(C) Ferric chloride
(D) Copper chloride
(ii) If the molecular formula of an organic compounds is C10H18 it is:
(A) alkene
(B) alkane
(C) alkyne
(D) Not a hydrocarbon
(iii) Which of the following is a common characteristic of a covalent compound?
(A) high melting point
(B) consists of molecules
(C) always soluble in water
(D) conducts electricity when it is in the molten state
(iv) To increase the pH value of a neutral solution, we should add:
(A) an acid
(B) an acid salt
(C) an alkali
(D) a salt
(v) Anhydrous iron (III) chloride is prepared by:
(A) direct combination
(B) simple displacement
(C) decomposition
(D) neutralization
Ans. (i) (D) copper chloride
(ii) (C) alkyne
(iii) (B) consists of molecules
(iv) (C) an alkali
(v) (A) direct combination
(c) Identify the substance underlined, in each of the following cases: [5]
(i) Cation that does not form a precipitate with ammonium hydroxide but forms one with sodium hydroxide.
(ii) The electrolyte used for electroplating an article with silver.
(iii) The particles present in a liquid such as kerosene, that is a non-electrolyte.
(iv) An organic compound containing – COOH functional group.
(v) A solid formed by reaction of two gases, one of which is acidic and the other basic in nature.
Ans. (i) Ca2+
(ii) sodium silver cyanide solution Na[Ag(CN)2]
(iii) Free molecule
(iv) carboxylic acid
(v) ammonium chloride (NH4Cl)
(d) Write a balanced chemical equation for each of the following: [5]
(i) Action of cold and dilute nitric acid on copper.
(ii) Reaction of ammonia with heated copper oxide.
(iii) Preparation of methane from iodomethane.
(iv) Action of concentrated sulphuric acid on sulphur.
(v) Laboratory preparation of ammonia from ammonium chloride.
Ans.
(iv) S + 2H2SO4 (conc.) → 3SO2 + 2H2O
(v) 2NH4Cl + Ca(OH)2 → CaCl2 + 2H2O + 2NH3
(e) State one relevant observation for each of the following reactions: [5]
(i) Addition of ethyl alcohol to acetic acid in the presence of concentrated sulphuric acid.
(ii) Action of dilute hydrochloric acid on iron (II) sulphide.
(iii) Action of sodium hydroxide solution on ferrous sulphate solution.
(iv) Burning of ammonia in air.
(v) Action of concentrated sulphuric acid on hydrated copper sulphate.
Ans. (i) Fruit smell evolved (Ether).
(ii) H2S evolves with rotten egg smell.
(iii) Dirty green ppt [Fe(OH)2] which is insoluble in excess NaOH.
(iv) Burns with a green flame producing N2 and H2O.
(v) Blue crystal loses its crystalline shape and becomes white amorphous.
(f) (i) Draw the structural formula for each of the following: [5]
1. 2, 3 – dimethyl butane
2. diethyl ether
3. propanoic acid
(ii) From the list of terms given, choose the most appropriate term to match the given description.
(calcination, roasting, pulverisation, smelting)
1. Crushing of the ore into a fine powder.
2. Heating of the ore in the absence of air to a high temperature.
(ii) 1. Pulverisation
2. Calcination
(g) (i) Calculate the number of gram atoms in 4.6 grams of sodium (Na = 23). [5]
(ii) Calculate the percentage of water of crystallization in CuSO4.5H2O (H = 1, O = 16, S = 32, Cu = 64)
(iii) A compound of X and Y has the empirical formula XY2. Its vapour density is equal to its empiricial formula weight. Determine its molecular formula.
Ans. (i) 23 g of sodium = 1 gram atom
4.6 g of sodium = 1 /23 × 4.6 = 0.2 gram atom
(h) Match the atomic number 2, 4, 8, 15, and 19 with each of the following: [5]
(i) A solid non-metal belonging to the third period.
(ii) A metal of valency 1.
(iii) A gaseous element with valency 2.
(iv) An element belonging to Group 2.
(v) A rare gas.
Ans. (i) 15 (ii) 19
(iii) 8 (iv) 4
(v) 2
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ICSE Class 10 Chemistry Question Paper solved Set A
SECTION – II (40 MARKS)
(Attempt any four questions from this Section)
Question 2.
(a) Arrange the following as per the instruction given in the brackets: [4]
(i) He, Ar, Ne (Increasing order of the number of electron shells)
(ii) Na, Li, K (Increasing ionisation energy)
(iii) F, Cl, Br (Increasing electronegativity)
(iv) Na, K, Li (increasing atomic size)
Ans. (i) He, Ne, Ar
(ii) K, Na, Li
(iii) Br, Cl, F
(iv) Li, Na, K
(b) State the type of Bonding in the following molecules: [2]
(i) Water
(ii) Calcium oxide
Ans. (i) Water – Covalent bond
(ii) Calcium oxide – Electrovalent bond
(c) Answer the following questions: [2]
(i) How will you distinguish between ammonium hydroxide and sodium hydroxide using copper sulphate solutions?
(ii) How will you distinguish between dilute hydrochloric acid and dilute sulphuric acid using lead nitrate solution?
Ans. (i) Using NaOH, it forms blue ppt which is insoluble in excess NaOH. With NH4OH it forms blue ppt which is soluble in excess NH4OH.
(ii) Using lead nitrate solution, only HCl will form curdy white ppt and not H2SO4.
(d) Identify the salts P and Q from the observations given below: [2]
(i) On performing the flame test salt P produces a lilac coloured flame and its solution gives a white precipitate with silver nitrate solution, which is soluble in ammonium hydroxide solution.
(ii) When dilute HCl is added to a salt Q, a brisk effervescence is produced and the gas turns lime water milky.
When NH4OH solution is added to the above mixture (after adding dilutem HCl), it produces a white precipitate which is soluble in excess NH4OH solution.
Ans. (i) Salt ‘P’ is potassium chloride (KCl)
(ii) Salt ‘Q’ is zinc carbonate (ZnCO3)
Question 3.
(a) Draw an electron dot diagram to show the formation of each of the following compounds: [4]
(i) Methane
(ii) Magnesium chloride
[H = 1, C = 6, Mg = 12, Cl = 17]
Ans. (i) Methane [H = 1, C = 6]
Hydrogen atom: Z = 1
Configuration: 1
Carbon atom: Z = 6
Configuration: 2, 4
(ii) Magnesium chloride
Mg atom: Z = 12
Configuration: 2, 8, 2
Cl atom: Z = 17
Configuration: 2, 8, 7
(b) State the observations at the anode and at the cathode during the electrolysis of: [4]
(i) fused bromide using graphite electrodes.
(ii) copper sulphate solution using copper electrodes.
Ans. (i) At cathode, Pb2+ migrate to form silvery grey metallic lead.
At anode, Br– migrate forming bromide atom and then bromine molecule, ultimately forming bromine vapours. These are Reddish Brown Fumes.
(ii) At cathode, Cu2+ ions accept electrons and form neutral copper atom deposition here size of Anode gets decreases.
At anode, neither SO4 2– nor OH–, are discharged and copper atoms of the anode lose electrons and enter the solution as copper ions.
(c) Select the ion in each case, that would get selectively discharged from the aqueous mixture of the ions listed below: [2]
(i) SO42–, NO3 –, and OH–
(ii) Pb2+, Ag+ and Cu2+
Ans. (i) OH–
Question 4.
(a) Certain blank spaces are left in the following table and these are labelled as A, B, C, D and E. Identify each of them.
Ans. (i) A → NaHSO4 + HCl
B → Upward displacement of air
(ii) C → Mg3N2 + H2O
D → CaO (Calcium oxide)
E → By downward displacement of air
(b) Write balanced chemical equations to show
(i) The oxidizing action of conc. sulphuric acid on carbon.
(ii) The behaviour of H2SO4 as an acid when it reacts with magnesium.
(iii) The dehydrating property of conc. sulphuric acid with sugar.
Ans.
(c) Write balanced chemical equations to show how SO3 is converted to sulphuric acid in the contact process.
Ans. SO3 + H2SO4 → H2S2O7
H2S2O7 + H2O → 2H2SO4
Question 5.
(a) (i) Propane burns in air according to the following equation: [4]
C3H8 + 5O2 → 3CO2 + 4H2O.
What volume of propane is consumed on using 1000 cm3 of air, considering only 20% of air contains oxygen?
(ii) The mass of 11.2 litres of a certain gas at s.t.p. is 24 g. Find gram molecular mass of the gas.
Ans. (i) According to the equation
C3H8 + 5O2 → 3CO2 + 4H2O
1 vol : 5 vol : : 3 vol : 4 vol
(b) A gas cylinder can hold 1 kg of hydrogen at room temperature and pressure: [4]
(i) Find the number of moles of hydrogen present.
(ii) What weight of CO2 can the cylinder hold under similar conditions of temperature and pressure? (H = 1, C = 12, O = 16)
(iii) If the number of molecules of hydrogen in the cylinder is x, calculate the number of CO2 molecules in the cylinder under the same conditions of temperature and pressure.
(iv) State the law that helped you to arrive at the above result.
Ans. (i) Molecular mass of hydrogen = 2 × 1 g
2 g is present in 1 mole
∴ 1000 g (1 kg) = 1/2 × 1000 = 500 moles
(ii) Molecular mass of CO2 = 12 + 16 × 2 = 44 g
1 mole = 44 g
∴ 500 moles = 44 × 500 = 22000 g = 22 kg
(iii) The number of molecules of CO2 in the cylinder is X.
(iv) Avogadro’s Law – Under same condition of temperature and pressure, equal volumes of gases contain the same number of molecules.
(c) Write a balanced chemical equation for the preparation of each of the following salts: [2]
(i) Copper carbonate (ii) Ammonium sulphate crystals
Ans. (i) CuCl2 + Na2CO3 ® 2NaCl + CuCO3 ¯
(ii) (NH4)2CO3 + H2SO4 ® (NH4)2SO4 + H2O + CO2
Question 6.
(a) Give a balanced chemical equation for each of the following: [4]
(i) Action of conc. nitric acid on sulphur.
(ii) Catalytic oxidation of ammonia.
(iii) Laboratory preparation of nitric acid.
(iv) Reaction of ammonia with nitric acid.
(b) Identify the term or substance based on the descriptions given below: [4]
(i) Ice like crystals formed on cooling an organic acid sufficiently.
(ii) Hydrocarbon containing a triple bond used for welding purposes.
(iii) The property by virtue of which the compound has the same molecular formula but different structural formulae.
Ans. (i) Glacial acetic acid
(ii) Acetylene
(iii) Isomerism
(iv) Ketone
(c) Give a balanced chemical equation for each of the following: [2]
(i) Preparation of ethane from sodium propionate.
(ii) Action of alcoholic KOH on bromoethane.
Question 7.
(a) Name the following: [4]
(i) The process of coating of iron with zinc.
(ii) An alloy of lead and tin that is used in electrical circuits.
(iii) An ore of zinc containing its sulphide.
(iv) A metal oxide that can be reduced by hydrogen.
Ans. (i) Galvanisation
(ii) Solder
(iii) Zinc sulphide or Zinc blende (ZnS)
(iv) CuO
(b) Answer the following questions with respect to the electrolytic process in the extraction of aluminum: [3]
(i) Identify the components of the electrolyte other than pure alumina and the role played by each.
(ii) Explain why powdered coke is sprinkled over the electrolytic mixture.
Ans. (i) Cryolite – lower fusion temperature.
Fluorspar – acts as solvent for electrolytic mixture and increase conductivity.
(ii) To reduce heat loss by radiation and prevent the burning of carbon anode.
(c) Complete the following by selecting the correct option from the choices given:
(i) The metal which does not react with water or dilute H2SO4 but reacts with concentrated H2SO4 is .____ (Al/Cu/Zn/Fe)
(ii) The metal whose oxide, which is amphoteric, is reduced to metal by carbon reduction .____ (Fe/Mg/Pb/Al)
(iii) The divalent metal whose oxide is reduced to metal by electrolysis of its fused salt is ._____ (Al/Na/Mg/K)
Ans. (i) Cu (ii) Pb (iii) Mg