Class 10 chemistry ICSE CHEMISTRY MODEL PAPER 1

ICSE CLASS 10 CHEMISTRY

MODEL PAPER 1

ICSE EXAMINATION

Class-X                                                                                                                                        Marks:80

Subject: Chemistry                                                                                                                   Time:2Hrs.

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 on 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)

Answer all the questions

Question 1

a) Select the correct answers from A, B, C or D for the following statements:                          5M  

i)  An element ‘X’ belongs to Group 2 of period 3. Then ‘X’ has

A) 3 valence electrons and 2 shells

B) 2 valence electrons and 3 shells

C) 2 valence electrons and 2 shells

D) 1 valence electron and 2 shells

ii)   Which of the following compounds involves formation of coordinate bonding?

A)    CCl₄                                              B) H₂                                        C) HCl                     D) NH₄Cl

iii)    Which of the followings not an alloy of Copper?

A)    Brass                                 B) Bronze                       C) Solder                  D) Duralumin

iv)    The catalyst used in the preparation of Ammonia in Haber’s process:

A) Iron                                      B) Platinum                    C) Silver                   D) Nickel

v)      Which of the following properties doesnot describe the properties of alkenes?

A) They are unsaturated hydrocarbons

B) They decolourise Bromine water

C) They can undergo addition reactions as well as substitution reactions.

D) They undergo combustion reaction with Oxygen forming Carbon dioxide and Water.

b) Fill in the blanks:-                                                                                                                      5M           

i)        Metals tend to __________ (lose/gain) electrons.

ii)      _______________ (Electrorefining / electroplating) makes an article attractive.

iii)    Cold dilute Nitric acid reacts with Copper metal to form ___________ (Nitrogen dioxide/Nitrous oxide/Nitric oxide).

iv)    Sodium ethanoate reacts with Soda lime to release ____________ (Methane/Ethane) gas.

v)      Cations formed by _________ electrons are reduced at ___________. (gaining, losing, cathode, anode)

c) Name the following.                                                                                                               5M  

i)        A metal present in period 3 with 1 valence electron.

ii)      The element with highest electronegativity.

iii)    A covalent compound which behaves like an electrovalent compound in its aqueous solution.

iv)    An acid which is present in vinegar.

v)      The explosive liquid formed when ammonia reacts with excess Chlorine gas.                    

d) Distinguish between the following pair of compounds using a common reagent.                           5M    

i)        Ethene and Ethyne

ii)      Dil. Hydrochloric acid and dil. Nitric acid.

iii)    Sodium chloride and Zinc chloride.

iv)    Calcium carbonate and Calcium nitrate

v)      Magnesium sulphate and Magnesium chloride.

e) Give reason why:                                                                                                                  5M

i) The oxidizing power of elements increases across a period from left to right.

ii) Dilute H₂SO₄ is preferred dil. HNO₃ to dilute water before its electrolysis.

iii) In the electrolysis of Alumina in Hall Heroult’s process the electrolyte is covered with powdered coke.

iv) Ammonium nitrate is not used in the preparation of Ammonia gas.

v) Alkenes are more reactive than alkanes.

f) State your observations :                                                                                                       5M    

i) At anode when aqueous solution of Copper sulphate is electrolysed using copper electrodes.

ii) Copper carbonate is heated in a hard test tube.

iii) A few drops of dil. HCl is added to Silver nitrate solution followed by the addition of Ammonium hydroxide solution.

iv) Ammonium hydroxide is added to Lead nitrate solution in small amounts then in

     excess.

v) Sodium chloride crystals are heated with conc. Sulphuric acid.

g) Select the suitable word from the list given in brackets for each of the following statements.     5M      

(Sodium chloride, Magnesium chloride, K⁺, Lead chloride, PbO, Cu²⁺, FeO)

i)        A deliquescent substance.

ii)      A chloride insoluble in cold water but soluble in hot water.

iii)    An amphoteric oxide.

iv)    The ion which could be discharged most readily at cathode.

v)      A soluble salt.

h) (NH₄)₂Cr₂O₇    N₂ + 4H₂O + Cr₂O₃                                                                                                             5M

         (at. wt. H-1, N-14, O-16, Cr-52)

A) If 63 g of Ammonium dichromate is heated:

i) Calculate the volume of Nitrogen gas produced.

ii) The number of moles of Ammonium dichromate taken.

iii) The mass of Cr₂O₃  formed.

B) i) Calculate the amount of (NH₄)₂Cr₂O₇ to be taken to produce 44.8lit. of Nitrogen gas.

ii) Find the number of moles of Nitrogen gas produced.

 Section II (40 Marks)  Answer any four of the following questions

Question 2                                                                                                                                 5+5

a)      A, B, C and D are the elements with valence electrons 6, 3, 4 and 1 respectively. Answer the following:

i)  Nature of the bonding between C and A.

ii) Formula of the compound between B and A.

iii) Nature of the bonding between D and A. and draw the electron dot structure of that compound.

iv)  If A is a non metal containing diatomic molecule then write balanced equation for the reaction between A and B.

v) If they all belong to same period which of them is most electro negative?

b)      Salts A,B,C,D and E undergo the following reactions i-v respectively. Then find the anions present each salt.

i) When AgNO₃ is added to the solution of A, a white precipitate is formed which is insoluble in dil. HNO₃.

ii) Addition of dil. HCl to B produces a gas which turns Lead acetate paper black.

iii) When a freshly prepared solution of FeSO₄ is added to a solution of C and conc. H₂SO₄  is gently added , a brown ring is formed.

iv) When dil. Sulphuric acid is added to D a gas is produced which turns lime water milky and turns acidified K₂Cr₂O₇ to clear green.

v) Dil. Hydrochloric acid is added to a solution of ‘E’. A gas is release which turns lime water milky but has no effect on acidified K₂Cr₂O₇.

Question 3                                                                                                                             5+3+2

a)

		IA	IIA											IIIA		IVA		VA		VIA		VIIA	0
		1	2	3	4	5	6	7	8	9				13		14		15		16		17	18
1		A
2			E											Q				D		X		Z
3		C	H													T				Y			J
4		M

i) State the number of shells present in ‘C’.

ii) Formula of the compound between ‘Q’ and ‘X’.

iii) What type of bonding is possible between A and Z.

iv) Which one has the highest electronegativity among the elements belonging to Period 3. (from the given table).

v) Identify the metalloids in the table.

b) Give one suitable term for the following statements.

i) The energy required to remove one valence electron from a gaseous atom.

ii) The tendency of an element to attract bond pair of electrons to itself.

iii) Physical and chemical properties of elements are periodic functions of their atomic number.

c) i)  Name the process in which Sulphuric acid is manufactured in large amounts.

   ii) Give one chemical test for dil. Sulphuric acid.

Question 4

a)      The following diagram shows the laboratory preparation of Ammonia gas.         5+3+2

i) Identify X and Y.

ii) State the nature of the gas prepared.

iii) Give a balanced equation for the above preparation.

iv) Name the drying agent.

v) State how will you find out that the jar is full of Ammonia gas?

b)       

i)     In laboratory preparation of Hydrochloric acid , HCl gas is dissolved in water using funnel arrangement. Give any two reasons for the same

ii)      Write balanced equation for the laboratory preparation of HCl gas.

c)      Write any two reactions which show the reducing property of Ammonia gas.

Question 5                                                                                                                            2+4+2+2

a) i) What volume of Oxygen is required to burn completely 90dm³ of Butane under similar conditions.

2C₄H₁₀ + 13O₂ à 8CO₂ + 10H₂O

ii) The mass of 5.6dm³ of a gas at STP is 12g. Calculate the relative molecular mass of the gas.

b) i) An organic compound has vapour density 94. It contains C=12.67%. H=2.13% and

Br=85.11%. Find the molecular formula of the given organic compound. (C-12,H-1,Br-80)

ii) Hydrogen gas contains X number of molecules under certain pressure and temperature. Find the number of molecules that the same volume of Oxygen contains under same conditions.

c) Write balanced equations for the following reactions:

i) ZnO reacts with Sodium hydroxide

ii) Ferric chloride from Iron

d) Name the gases released in the following cases:

i) dil. HCl is added to a metal carbonate

ii) An alkali is heated with an Ammonium salt.

Question 6                                                                                                                            3+3+2+2

a)      i) A solution of Silver nitrate is a good electrolyte but not used as electrolyte for electroplating with Silver. Why?

ii) Write balanced electrode equation at cathode during electrolysis of Copper sulphate using inert electrodes.

iii) Name the products formed during the electrolysis of acidified water. (mention the electrode and write answer)

b)       i) State any two conditions during electro plating.

ii) State one difference between a strong electrolyte and a weak electrolyte.

c)      Answer the following questions pertaining electrolysis of Alumina.

i) Name the process.

ii) What is the significance of the Aluminium compound other than Alumina in this process?

d)     Name the following:

i) The chemical added to the ore to get rid of impurities.

ii) An allotrope a  non metal which is a good conductor of electricity.

Question 7                                                                                                                               2+3+2+3

a)      Write the branched structures of the following compounds:

i) 1,2-di chloro ethane             ii) Di methyl ether

b)      i) Give reason why  Ethene under goes addition reactions but Ethane does not.

ii) State your observation when is Ethene passed through Bromine water.

iii) Name the process of removal of Carbon dioxide from a carboxylic acid.

c)      Write balanced equations for the following reactions:

i) Dehydration of Ethyl alcohol at 170⁰C using a dehydrating agent.

ii) Esterification of Acetic acid.

d) Copy and complete the following table:

Salt Solution	On addition of NH4OH in small quantity	On addition of NH4OH in excess	Cation present in the salt solution
A			Fe2+
B	Gelatinous white ppt.
C		Inky blue solution