Solving ICSE Class 10 Chemistry Previous Year Question Papers ICSE Class 10 Chemistry Question Paper 2014 is the best way to boost your preparation for the board exams.
ICSE Class 10 Chemistry Question Paper 2014 Solved
Time : 2 hour
Maximum Marks: 40
General Instructions:
- 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 [ ].
SECTION -1 (40 MARKS)
(Attempt all questions from this Section)
Question 1.
(a) Choose the correct answer from the options given below: [10]
(i) Ionisation Potential increases over a period from left to right because the:
(A) Atomic radius increases and nuclear charge increases
(B) Atomic radius decreases and nuclear charge decreases
(C) Atomic radius increases and nuclear charge decreases
(D) Atomic radius decreases and nuclear charge increases.
Answer:
(D) Atomic radius decreases and nuclear charge increases.
(ii) A compound X consists of only molecules. Hence X will have:
(A) A crystalline hard structure
(B) A low melting point and low boiling point
(C) An ionic bond
(D) A strong force of attraction between its molecules.
Answer:
(B) A low melting point and low boiling point
(iii) When fused lead bromide is electrolysed we observe:
(A) a silver grey deposit at anode and a reddish brown deposit at cathode
(B) a silver grey deposit at cathode and a reddish brown deposit at anode
(C) a silver grey deposit at cathode and reddish brown fumes at anode
(D) silver grey fumes at anode and reddish brown fumes at cathode.
Answer:
(C) a silver grey deposit at cathode and reddish brown fumes at anode
(iv) The main ore used for the extraction of iron is:
(A) Haematite
(B) Calamine
(C) Bauxite
(D) Cryolite
Answer:
(C) Bauxite
(v) Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting point is known as:
(A) smelting
(B) ore dressing
(C) calcination
(D) bessemerisation
Answer:
(C) calcination
(vi) If an element A belongs to Period 3 and Group II then it will have,
(A) 3 shells and 2 valence electrons
(B) 2 shells and 3 valence electrons
(C) 3 shells and 3 valence electrons
(D) 2 shells and 2 valence electrons
Answer:
(B) 2 shells and 3 valence electrons
(vii) The molecule containing a triple co-valent bond is:
(A) ammonia
(B) methane
(C) water
(D) nitrogen
Answer:
(D) nitrogen
(viii) The electrolyte used for electroplating an article with silver is:
(A) silver nitrate solution
(B) silver cyanide solution
(C) sodium argentocyanide solution
(D) nickel sulphate solution
Answer:
(C) sodium argentocyanide solution
(ix) Aluminium powder is used in thermite welding because,
(A) it is a strong reducing agent
(B) it is a strong oxidising agent
(C) it is corrosion resistant
(D) it is a good conductor of heat.
Answer:
(A) it is a strong reducing agent
(x) The I.U.P.A.C. name of acetylene is,
(A) propane
(B) propyne
(C) ethene
(D) ethyne.
Answer:
(D) ethyne.
(b) Fill in the blanks from the choices given within brackets: [5]
(i) The basicity of Acetic Acid is . (3, 1, 4)
(ii) The compound formed when ethanol reacts with sodium is (sodium ethanoate, sodium ethoxide, sodium propanoate)
(iii) Quicklime Is not used to dry HCl gas because (CaO is alkaline, CaO is acidic, CaO is neutral)
(iv) Ammonia gas is collected by (an upward displacement of air, a downward displacement of water, a downward displacement of air)
(v) Cold, dilute nitric acid reacts with copper to form dioxide, nitric oxide).
Answer:
(i) 1
(ii) Sodium ethoxide
(iii) CaO is alkaline
(iv) Downward displacement of air.
(v) Nitric oxide.
(c) Give one word or phrase for the following:
(i) The ratio of the mass of a certain volume of gas to the mass of an equal volume of hydrogen under the same conditions of temperature and pressure.
(ii) Formation of ions from molecules.
(iii) Electrolytic deposition of a superior metal on a baser metal.
(iv) Hydrocarbons containing
functional group.
(v) The amount of energy released when an atom in the gaseous state accepts an electron to form an anion. [5]
Answer:
(i) Vapour density
(ii) Ionisation
(iii) Electroplating
(iv) Ketones
(v) Electron affinity
(d) Match the options A to E with the statements (i) to (v): [5]
| A. alkynes | (i) No. of molecules In 22.4 dm3 of carbon dioxide at s.t.p. |
| B. alkane | (ii) An element with electronic configuration 2, 8, 8,3 |
| C. iron | (iii) CnH2n+2 |
| D. 6.023 × 1023 | (iv) CnH2n-2 |
| E. metal | (v) The metal that forms two types of ions |
Answer:
| A. alkynes | (iv) CnH2n-2 |
| B. alkane | (iii) CnH2n+2 |
| C. iron | (v) The metal that forms two types of ions |
| D. 6.023 × 1023 | (i) No. of molecules In 22.4 dm3 of carbon dioxide at s.t.p. |
| E. metal | (ii) An element with electronic configuration 2, 8, 8,3 |
(e) Write balanced equations for the following:
(i) Action of heat on a mixture of copper and concentrated nitric acid.
(ii) Action of warm water on magnesium nitride.
(iii) Action of concentrated sulphuric acid on carbon.
(iv) Action of dilute hydrochloric acid on sodium sulphide.
(v) Preparation of ethane from sodium propionate. [5]
Answer:
(i)
(ii) Mg3N2 + 6H2O → 3Mg(OH)2 + 2NH3↑
(iii) C + 2H2SO4 → CO2↑ + 2H2O + 2SO2↑
(iv) Action of dilute hydrochloric acid on sodium suiphide.
Na2S + 2HCl → 2NaCl + H2S
(v)
(f) Distinguish between the following pairs of compounds using the test given within brackets:
(i) Iron (II) sulphate and iron (III) sulphate (using ammonium hydroxide)
(ii) A lead salt and a zinc salt (using excess ammonium hydroxide)
(iii) Sodium nitrate and sodium sulphite (using dilute sulphuric acid)
(iv) Dilute sulphuric acid and dilute hydrochloric acid (using barium chloride solution)
(v) Ethane and ethene (using alkaline potassium permanganate solution) [5]
Answer:
| (i) Iron (II) sulphate FeSO4 + 2NH4OH → Fe(OH)2 ↓ +(NH4)2SO4 Dirty green ppts. of Fe(OH)2 are formed. |
Iron (III) sulphate Fe2(SO4)3+ 3NH4OH → Fe(OH) 3 ↓ + 3NH4C1 Reddish brown ppts. of Fe(OH)3 are formed. |
| (ii) A lead salt Pb(NO3)2 + 2NH4OH → Pb(OH)2 ↓ + 2NH4NO3 It is insoluble in excess and forms chalky white precipitates. |
A zinc salt ZnSO4 + 2NH4OH → Zn(OH)2 ↓ +(NH4)2SO4 Zn(OH)2 + (NH4)2SO4 + 2NH4OH → [Zn(NH3)4]SO4 + 4H2O It is soluble in excess and forms gelatinous white precipitates. |
| (iii). NaN03 (Sodium nitrate) 2NaNO3 + H2SO4 → Na2SO4 + 2HNO3 |
Na2SO3 (Sodium sulphite) Na2SO3 + H2SO4 → Na2SO4+ H2O + SO2 |
| (iv) Dilute H2SO4 BaCl2 + H2SO4 Ba(SO4)2 ↓ + 2HCl If forms white ppt. of Ba(S04)2. |
Dilute HCl BaCl2 + HCl → No reaction No precipitates are formed. |
| (v) Ethane The pink colour of KMnO4 remains the same. |
Ethene The pink colour of KMnO4 is discharged. |
(g) (i) Oxygen oxidises ethyne to carbon dioxide and water as shown by the equation:
2C2H2 + 5o2 → 4CO2 + 2H2O
What volume of ethyne gas at s.t.p. is required to produce 8.4 dm3 of carbon dioxide at s.t.p.? [H = 1, C = 12, O = 16]
Answer:
(ii) A compound made up of two elements X and Y has an empirical formula X,Y. If the atomic weight of X is 10 and that of Y is 5 and the compound has a vapour density 25, find its molecular formula. [5]
Answer:
Empirical formula = X2Y
Atomic weight of X = 10
Atomic weight of Y = 5
V.D. of compound = 25
M.F. = ?
Molecular mass = 2 × V.D.
= 2 × 25 = 50
Empirical mass = 2 × 10 + 5
= 20 + 5
= 25
Molecular mass
n = \(\frac{\text { Molecular mass }}{\text { Empirical mass }}\)
= \(\frac{50}{25}\)
= 2
Molecular formula = (E.F.)2
= (X2Y)2
= X4Y2
SECTION – II (40 MARKS)
(Attempt any four questions from this Section)
Question 2.
(a) State your observation in each of the following cases:
(i) When dilute hydrochloric acid is added to sodium carbonate crystals.
(ii) When excess sodium hydroxide is added to calcium nitrate solution.
(iii) At the cathode when acidified aqueous copper sulphate solution is electrolyzed with copper electrodes.
(iv) When calcium hydroxide is heated with ammonium chloride crystals.
(v) When moist starch iodide paper is introduced into chlorine gas. [5]
Answer:
(i) Brisk effervescence of a gas which turns lime water milky (CO2) is evolved.
(ii) White precipitates are formed that are sparingly soluble in water.
(iii) Reddish metal (copper) is deposited on cathode.
(iv) An ammonical smelling gas (NH3) is released.
(v) It turns moist starch iodide paper blue black.
(b) Study the figure given below and answer the questions that follow:
(i) Identify the gas Y.
(ii) What property of gas Y does this experiment demonstrate?
(iii) Name another gas which has the same property and can be demonstrated through this experiment. [3]
Answer:
(i) Hydrogen chloride.
(ii) High solubility of hydrogen chloride.
(iii) Ammonia.
(c) (i) Name the other ion formed when ammonia dissolves in water.
(ii) Give one test that can be used to detect the presence of the ion produced. [2]
Answer:
(i) Hydroxyl [NH3 + H2O ⇌ NH4OH → NH4+ + OH–]
(ii) It turns red litmus blue.
Question 3.
(a) State the conditions required for the following reactions to take place:
(i) Catalytic hydrogenation of ethyne.
(ii) Preparation of ethyne from ethylene dibromide.
(iii) Catalytic oxidation of ammonia to nitric oxide.
(iv) Any two conditions for the conversion of sulphur dioxide to sulphur trioxide. [5]
Answer:
(i) Nickel at 200°C
(ii) Alcoholic KOH (KOH alc.)
(iii) Platinum at 800°C
(iv) U2O5 as catalyst and K2O as a promoter.
Temperature → 450 – 500°C
(b) State the main components of the following alloys:
(i) Brass.
(ii) Duralumin.
(iii) Bronze, [3]
Answer:
(i) Copper and zinc
(ii) Aluminium, copper, magnesium and manganese
(iii) Copper, zinc and tin
(c) Give balanced equations for the following:
(i) Laboratory preparation of nitric acid.
(ii) Preparation of ethanol from monochloroethane and aq. sodium hydroxide. [2]
Answer:
Question 4.
(a) Give the structural formula of the following:
(i) ethanol.
(ii) 1-propanal.
(iii) ethanoic acid.
(iv) 1,2, dichloroethane. [4]
Answer:
Give the structural formula:
(b) Draw the structure of the stable positive ion formed when an acid dissolves in water. [2]
Answer:
(c) State the inference drawn from the following observations:
(i) On carrying out the flame test with a salt P a brick red flame was obtained. What is the cation in P?
(ii) A gas Q turns moist lead acetate paper silvery black. Identify the gas Q.
(iii) pH of liquid R is 10. What kind of substance is R?
(iv) Salt S is prepared by reacting dilute sulphuric acid with copper oxide. Identify S.
Answer:
(i) Cation in P is Ca2+.
(ii) Hydrogen sulphide
(iii) R is a basic substance as its pH is greater
(iv) Copper sulphate (CuSO4) greater than 7
Question 5.
(a) Name the following:
(i) The property possessed by metals by which they can be beaten into sheets.
(ii) A compound added to lower the fusion temperature of electrolytic bath in the extraction of aluminium.
(iii) The ore of zinc containing its sulphide. [3]
Answer:
(i) Malleability
(ii) Cryolite
(iii) Zinc Blende.
(b) Give one equation each to show the following properties of sulphuric acid:
(i) Dehydrating property.
(ii) Acidic nature.
(iii) As a non-volatile acid. [3]
Answer:
(i)
im – 6
(ii) It reacts with alkalies and shows neutralisation reaction.
2NaOH + H2SO4 → Na2SO4 + 2H2O.
(iii)
im – 7
(c) Give balanced chemical equations to prepare the following salts:
(i) Lead sulphate from lead carbonate.
(ii) Sodium sulphate using dilute sulphuric acid.
(iii) Copper chloride using copper carbonate. [4]
Answer:
(i)
Note: To convert insoluble salt to insoluble salt, two step reaction is needed i.e., to convert insoluble into soluble and then soluble to insoluble.
(ii)
(iii) CuCO3 + 2HCl → CuCl2 + H2O + CO2
Question 6.
(a) (i) State Avogadro’s Law.
(ii) A cylinder contains 68g of ammonia gas at s.t.p.
1. What is the volume occupied by this gas?
2. How many moles of ammonia are present in the cylinder?
3. How many molecules of ammonia are present in the cylinder? [N-14, H-1] [4]
Answer:
(i) Avogadro’s Law states that equal volumes of all gases under similar conditions of temperature and pressure contain the same no. of molecules.
(ii) Cylinder contains ammonia = 68 g
(1) Molecular mass of ammonia = [NH3] = 14 + 3 = 17g
17 g of ammonia at s.t.p. occupies volume = 22.4 L
1 g of ammonia at s.t.p. occupies volume 22.4
= \(\frac{22.4}{17}\) L
68 g of ammonia at s.t.p. occupies volume = \(\frac{22.4}{17}\) × 68 = 89.6 L
(2) 17 g of ammonia = 1 mole
1 g of ammonia = \(\frac{1}{17}\) mole
68 g of ammonia = \(\frac{1}{17}\) × 68 mole = 4 mole of ammonia
(3) 1 mole contains = 6.022 × 1023 molecules
4 mole contains = 4 × 6.022 × 1023
= 24.088 × 1023 molecules
(b) (i) Why do covalent compounds exist as gases, liquids or soft solids?
(ii) Which electrode: anode or cathode is the oxidising electrode? Why? [3]
Answer:
(i) Covalent compounds are bound by weak van der Waal forces of attraction so the molecules of the compound are loosely bound, thus due to weak forces they exist as gases, liquids or soft solids.
(ii) Anode is oxidising anode because loss of electrons takes place at anode.
(c) Name the kind of particles present in:
(i) Sodium Hydroxide solution.
(ii) Carbonic acid.
(iii) Sugar solution. [3]
Answer:
(i) Ions
(ii) Ions as well as molecules
(iii) Molecules
Question 7.
(a) An element Z has atomic number 16. Answer the following questions on Z:
(i) State the period and group to which Z belongs.
(ii) Is Z a metal or a non-metal?
(iii) State the formula between Z and Hydrogen.
(iv) What kind of a compound is this? [4]
Answer:
(i)
It is in 3rd period and 16th group.
(ii) Non-metal
(iii)
(iv) Covalent compound
(b) M is a metal above hydrogen in the activity series and its oxide has the formula M20. This oxide when dissolved in water forms the corresponding hydroxide which is a good conductor of electricity. In the above context answer the following:
(i) What kind of combination exists between M and O?
(ii) How many electrons are there in the outermost shell of M?
(iii) Name the group of which M belongs.
(iv) State the reaction taking place at the cathode.
(v) Name the product at the anode. [5]
Answer:
(i) Electrovalent combination
(ii) 1 electron is present in M
(iii) Alkali metals
(iv) M2O → 2M+ + O2- at cathode,
M+ + 1e– → M
(v) At anode
O2- – 2e– → O
[O] + [O] → O2↑