ICSE 2016 Chemistry Question Paper Solved for Class 10

Solving ICSE Class 10 Chemistry Previous Year Question Papers ICSE Class 10 Chemistry Question Paper 2016 is the best way to boost your preparation for the board exams.

ICSE Class 10 Chemistry Question Paper 2016 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) Fill in the blanks with the choices given in brackets. [5]
(i) Metals are good ________ (oxidizing agents/reducing agents) because they are electron ________ (acceptors/donors).
(ii) Electrovalent compounds have ________ (high/low) melting points.
(iii) Higher the pH value of a solution, the more ________ (acidic/alkaline) it is.
(iv) ________ (AgCl / PbClj), a white precipitate is soluble in excess NH4OH.
(v) Conversion of ethene to ethane is an example of ________ (hydration/hydrogenation).
Answer:
(i) reducing agents; donors
(ii) high
(iii) alkaline
(iv) AgCl (because of formation of diammine silver chloride)
(v) hydrogenation

(b) Choose the correct answer from the options given below : [5]
(i) An element with the atomic number 19 will most likely combine chemically with the element whose atomic number is :
(A) 17
(B) 11
(C) 18
(D) 20
Answer:
(A) 17

(ii) The ratio between the number of molecules in 2 g of hydrogen and 32 g of oxygen is :
(A) 1:2
(B) 1 : 0.01
(C) 1:1
(D) 0.01 : 1 [Given that H = 1, O = 16]
Answer:
(C) 1:1

(iii) The two main metals in Bronze are :
(A) Copper and zinc
(B) Copper and lead
(C) Copper and nickel
(D) Copper and tin
Answer:
(D) Copper and tin

(iv) The particles present in strong electrolytes are :
(A) only molecules
(B) mainly ions
(C) ions and molecules
(D) only atoms
Answer:
(B) mainly ions

(v) The main of the Fountains Experimeter is to prove that :
(A) HCl turns blue litmus red
(B) HCl is denser than air
(C) HCl is highly soluble in water
(D) HCl fumes in moist air.
Answer:
(C) HCl is highly soluble in water

(c) Write balanced chemical equations for each of the following : [5]
(i) Action of warm water on AIN.
(ii) Action of hot and concentrated Nitric acid on copper.
(iii) Action of Hydrochloric acid on sodium bicarbonate.
(iv) Action of dilute Sulphuric acid on Sodium Sulphite.
(v) Preparation of ethanol from Ethyl Chloride.
Answer:
(i) AIN + 3H₂O → Al(OH)₃ + NH₃↑
(ii) Cu + 4HNO₃ → Cu(NO₃)₂ + 2H₂O + 2NO₂↑
(iii) NaHCO₃ + HCl → NaCl + H₂O + CO₂↑
(iv) Na₂SO₃ + H₂SO₄ → Na₂SO₄ + H₂O + S0₂↑
(v) C₂H₅Cl + NaOH(aq) → C₂H₅OH + NaCl

(d) State your observations when : [5]
(i) Dilute Hydrochloric acid is added to Lead nitrate sodium and the mixture is heated.
(ii) Barium chloride solution is mixed with Sodium Sulphate Solution.
(iii) Concentrated Sulphuric acid is added to Sugar Crystals.
(iv) Dilute Hydrochloric acid is added to Copper carbonate.
(v) Dilute Hydrochloric acid is added to Sodium thiosulphate.
Answer:
(i)

When dilute hydrochloric acid is added to lead nitrate white precipitates of lead chloride are formed.
(ii)

When sodium sulphate is mixed with barium chloride. White coloured precipitates of Barium sulphate are formed.
(iii)

When conc. sulphuric acid is added to sugar crystals black spongy mass (sugar charcoal) is formed.
(iv)

When dilute hydrochloric acid is added to copper carbonate brisk effervescence due to the liberation of carbon dioxide is observed.
(v)

When dilute hydrochloric acid is added to sodium thiosulphate yellow residue (due to formation of sulphur) is formed and a gas with choking odour is formed.

(e) Identify the term/substance in each of the following : [5]
(i) The tendency of an atom to attract electrons to itself when combined in a compound.
(ii) The method used to separate ore from gangue by preferential wetting.
(iii) The catalyst used in the conversion of ethyne to ethane.
(iv) The type of reactions alkenes undergo.
(v) The electrons present in the outermost shell of an atom.
Answer:
(i) Electronegativity
(ii) Froth flotation process
(iii) Nickel or platinum or palladium
(iv) Addition reactions
(v) Valence electrons

(f) (i) A gas of mass 32 gms has a volume of 20 litres at S.T.P. Calculate the gram molecular weight of the gas. [5]
(ii) How much Calcium oxide is formed when 82 g of calcium nitrate is heated ? Also find the volume of nitrogendioxide evolved :
2Ca(NO₃)₂ → 2CaO + 4NO₂ + O₂
(Ca = 40, N = 14, O = 16)
Answer:
(i) 20 litres at S.T.P. weighs equal to 32 g
1 litre at S.T.P. weighs equal to \(\frac{32}{20}\) g
22.4 litres at S.T.P.
Weighs equal to \(\frac{32}{20}\) × 22.4 = 35.84 g

328 g will decompose to form 112 g of CaO
1 g will decompose to form \(\frac{112}{328}\)g of CaO
82g will decompose to form \(\frac{112}{328}\) × 82 g = 28 g of CaO
328 g will decompose to form 4 vol of N02 328 g will decompose to form 4 x 22.4 l of NO₂
1 g will decompose to form \(\frac{4 \times 22.4}{328}\) of NO₂
82 g will decompose to form = \(\frac{4 \times 22.4}{328}\) x 82
= 22.4 l of NO₂
= 1 Volume of NO₂

(g) Match the salts given in Column I with their method of preparation given in Column II :

Column I	Column II
(i) Pb(NO₃)₂ from PbO	(A) Simple displacement
(ii) MgCl₂ from Mg	(B) Titration
(iii) FeCl₃ from Fe	(C) Neutralization
(iv) NaNO₃ from NaOH	(D) Precipitation
(v) ZnCO₃, from ZnSO₄	(E) Combination

Answer:

Column I	Column II
(i) Pb(NO₃)₂ from PbO	(C) Neutralization
(ii) MgCl₂ from Mg	(A) Simple displacement
(iii) FeCl₃ from Fe	(E) Combination
(iv) NaNO₃ from NaOH	(B) Titration
(v) ZnCO₃, from ZnSO₄	(D) Precipitation

(h) (i) Write the IUPAC names of each of the following :

(ii) Rewrite the following sentences by using the correct symbol > (greater than) or < (less than) in the blanks given :
1. The ionization potential of Potassium is ________ that of Sodium.
2. The electronegativity of Iodine is ________ that of Chlorine.
Answer:
(i) 1. prop – 1 – ene
2. but – 2 – yne
3. ethanal

(ii) 1. < (less than)
2. < (less than)

SECTION – II (40 MARKS)
(Attempt any four questions from this Section)

Question 2.
(a) Use the letters only written in the Periodic Table Given below to answer the questions that follow : [4)

(i) State the number of valence electrons in atom J.
(ii) Which element shown forms ions with a single negative charge?
(iii) Which metallic element is more reactive than R?
(iv) Which element has its electrons arranged in four shells?
Answer:
(i) J → (5 valence electrons)
(ii) M → (7 valence electrons) so it forms a uninegative ion
(iii) T
(iv) T

(b) Fill in the blanks by selecting the correct word from the brackets :
(i) If an element has a low ionization energy then it is likely to be ________ (metallic / non-rnetallic).
(ii) If an element has seven electrons in its outermost shell then it is likely to have the ________ (largest / smallest) atomic size among all the elements in the same period.
Answer:
(i) metallic
(ii) smallest

(c) The following table shows the electronic configuration of the elements W, X, Y, Z :

Answer the following questions based on the table above
(i) What type of Bond is formed between :
1. W and X
2. Y and Z

(ii) What is the formula of the compound formed between : [2]
1. X and Z
2. W and X
Answer:
(i) 1. electrovalent bond
2. covalent bond

Question 3.
(a) Write a balanced chemical equation for each of the following : [3]
(i) Burning of ethane in plentiful supply of air.
(ii) Action of water on Calcium carbide.
(iii) Heating of Ethanol at 170°C in the presence of cone. Sulphuric acid.
Answer:
(i) C₂H₆ + \(\frac{7}{2}\)O₂ → 2CO₂ + 3H₂O
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
(ii) CaC₂ + 2H₂O → Ca(OH)₂ + C₂H₂ ↑

(b) Give the structural formulae of each of the following : [3]
(i) 2-methyl propane
(ii) Ethanoic acid
(iii) Butan – 2 – ol
Answer:

(c) Equation for the reaction when compound A is bubbled through bromine dissolved in carbon tetrachloride is as follows : [2]

(i) Draw the structure of A.
(ii) State your observationduring this reaction.
Answer:

(ii) Bromine water turns colourless.

(d) Fill in the blanks using the appropriate words given below : [2]
(Sulphur dioxide, Nitrogen dioxide, Nitric oxide, Sulphuric acid)
(i) Cold, dilute, nitric acid reacts with copper to given
(ii) Hot, concentrated nitric acid reacts with sulphur to form
Answer:
(i) nitric oxide
(ii) nitrogen dioxide

Question 4.
(a) Identify the gas evolved and give the chemical test in each of the following cases : [2]
(i) Dilute hydrochloric acid reacts with sodium sulphuric.
(ii) Dilute hydrochloric acid reacts with iron (II) sulphide.
Answer:
(i)

Chemical test: Sulphur dioxide decolorises potassium permanganate solution.
(ii)

Chemical test: Hydrogen sulphide turns lead acetate paper black.

(b) State your observations when ammonium hydroxide solution is added drop by drop and then in excess to each of the following solutions : [2]
(i) copper sulphate solution
(ii) zinc sulphate solution
Answer:
(i)

Pale blue precipitates are formed and then these precipitates dissolve in excess of ammonium hydroxide to form deep blue solution.
(ii)

When ammonium hydroxide is added drop by drop white gelatinous precipitate of zinc hydroxide is formed and on adding excess of ammonium hydroxide colourless solution is formed.

(c) Write equations for the reactions taking place at the two electrodes (mentioning clearly the name of the electrode) during the electrolysis of : [4]
(i) Acidified copper sulphate solution with copper electrodes.
(ii) Molten lead bromide with inert electrodes.
Answer:
(i) Dissociation reaction :

At cathode (negative terminal of battery)
Cu²⁺ + 2e^– → Cu(s)
copper metal gets deposited

At anode (positive terminal of battery)
Cu → Cu²⁺ + 2e^–
Copper metal gets converted into ions

(ii) Dissociation reaction

At cathode (negative terminal of battery)
Pb²⁺ + 2e^– → Pb
Lead metal is obtained in molten state
At anode (positive terminal of battery)
Br^– – le^– → Br
Br + Br → Br₂
Reddish brown vapours of bromine are formed

(d) (i) Name the product formed at the anode during the electrolysis of acidified water using platinum electrodes. [2]
(ii) Name the metallic ions that should be present in the electrolyte when an article made of copper is to be electroplated with silver.
Answer:
(i) Oxygen
(ii) Silver ions

Question 5.
(a) A gas cylinder contains 12 × 10²⁴ molecules of oxygen gas.
If Avogadro’s number is 6 × 10²³ ; Calculate :
(i) the mass of oxygen present in the cylinder.
(ii) the volume of oxygen at S.T.P. present in the cylinder. [O = 16]
Answer:
(i) 6 × 10²³ molecules are present the mass is 32 g

12 × 10²⁴ molecules are present than the mass is 32
\(\frac{32}{6 \times 10^{23}}\) × 12 × 10²⁴ = 32 × 20 = 640 g

(ii)

1 g will occupy a volume of \(\frac{22.4}{32}\)
640 g will occupy a volume of \(\frac{22.4}{32}\) × 640 = 448 l

(b) A gaseous hydrocarbon contains 82.76% of carbon. Given that its vapours density is 29, find its molecular formula. [C = 12, H = 1]
Answer:

E.F. = C₂H₅
E.F.M. = 12 × 2 + 5 × 1 = 24 + 5 = 29
V.D. = 29
M.M. = 2 × V.D. = 2 × 29 = 58
n = \(\frac{\text { M.M }}{\text { E.F.M }}=\frac{58}{29}\) = 2
Molecular formula = (C₂H₅)₂ = C₄H₁₀

(c) The equations 4NH₃ + 5O₂ → 4NO + 6H₂O, represents the catalytic oxidation of ammonia. If 100 cm3 of ammonia is used calculate the volume of oxygen required to oxidise the ammonia completely. [3]
Answer:

4 vol requires 5 vol
1 vol requires \(\frac{5}{4}\)
100 cm³ requires \(\frac{5}{4}\) × 100 = 125 cm³ of O₂

(d) By drawing an electron dot diagram show the formation of Ammonium Ion [Atomic No. : N = 7 and H = 1]
Answer:
N(7) → 2, 5 H(l) → 1

Question 6.
(a) Name the gas evolved when the following mixtures are heated : [2]
(i) Calcium hydroxide and Ammonium Chloride.
(ii) Sodium Nitrite and Ammonium Chloride.
Answer:
(i) Ammonia
(ii) Nitrogen

(b) Write balanced chemical equations for each of the following : [2]
(i) When excess of ammonia is treated with chlorine.
(ii) An equation to illustrate the reducing nature of ammonia.
Answer:
(i) 8NH₃ + 3Cl₂ → 6NH₄Cl + N₂
(ii) 3CuO + 2NH₃ → 3Cu + N₂ + 3H₂O

(c) A, B, C and D summarize the properties of sulphuric acid depending on whether it is dilute or concentrated. |3]
A = Typical acid property
B = Non-volatile acid
C = Oxidizing agent
D = Dehydrating agent
Choose the property (A, B, C or D) depending on which is relevant to each of the following :
(i) Preparation of Hydrogen chloride gas.
(ii) Preparation of Copper sulphate from copper oxide.
(iii) Action of cone. Sulphuric acid on Sulphur.
Answer:
(i) → B
(ii) → A
(iii) → C

(d) Give reasons why : [3]
(i) Sodium Chloride will conduct electricity only in fused or aqueous solution state.
(ii) In the electroplating of an article with silver, the electrolyte sodium argento- cyanide solution is preferred over silver nitrate solution.
(iii) Although copper is a good conductor of electricity, it is a non-electrolyte.
Answer:
(i) Sodium chloride is a solid, ionic compound, it has strong electrostatic forces of attraction. Only in the fused or aqueous solution, it forms ions which are capable of conducting electricity.
(ii) It is preferred over silver nitrate because the dissociation of AgNO₃ will be very fast and deposit will not be smooth and uniform.
(iii) An electrolyte must have free ions which act as charge carriers where as in copper the free electrons act as charge carriers.

Question 7.
(a) (i) Name the solution used to react the Bauxite as a first step in obtaining pure aluminium oxide, in the Baeyer’s process. [5]
(ii) Write the equation for the reaction where the aluminum oxide for the electrolytic extraction of aluminum is obtained by heating aluminum hydroxide.
(iii) Name the compound added to pure alumina to lower the fusion temperature during the electrolytic reduction of alumina.
(iv) Write the equation for the reaction that occurs at the cathode during the extraction of aluminium by electrolysis.
(v) Explain why it is preferable to use a number of graphite electrodes as anode instead of a single electrode, during the abvoe electrolysis.
Answer:
(i) Sodium hydroxide solution
(ii)

(iii) Cryolite (Na₃Al F₆) acts as a solvent and lower the fusion temperature from 2050°C to 950°C.
(iv) Cathode : (rich in electron)
Al³⁺ + 3e^– → Al
(v) It is preferable to use a number of graphite electrodes as anode because anode gets oxidised by the oxygen evolved.
Hence, if large number of electrodes are used it will keep the process continuous for a longer time.

(b) State what would you observe when : [2]
(i) Washing Soda Crystals are exposed to the atmosphere.
(ii) The salt ferric chloride is exposed to the atmosphere.
Answer:
(i) Na₂CO₃.10H₂O → Na₂CO₃.H₂O + 9H₂O
It will loose water of crystallisation and become a monohydrate. The appearance will be dull and flaky.
(ii). Ferric chloride is a deliquescent substance, thus it will absorb water from atmosphere and finally dissolve in that water forming a saturated solution.

(c) Identify the cations in each of the following case : [3]
(i) NaOH solution when added to the Solution (A) gives a reddish brown precipitate.
(ii) NH₄OH Solution when added to the Solution (B) gives white ppt. which does not dissolve in excess.
(iii) NaOH Solution when added to Solution (C) gives white ppt. which is insoluble in excess.
Answer:
(i) Ferric
(ii) Lead
(iii) Calcium