ICSE CHEMISTRY CLASS 10 - PRACTICE PAPER 13

ICSE CHEMISTRY CLASS 10 - PRACTICE PAPER 13

PRACTICE PAPER 13

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Class-IX                                                                                                                            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) Name the following.                                                                                                               5M

i) The electrolyte used in the electroplating an article with Silver.

ii) A colourless gas which turns alkaline Pyrogallol to dark brown.

iii) The number of hydronium ions produced by one molecule of an acid in its aqueous solution.

iv) The positively charged ions produced when Ammonia is dissolved in water.

v) The gas produced by the action of dilute Nitric acid on Copper.

b)   Match the following.                                                                                                            5M

Part-A

i)   Reduction electrode

ii) A solution containing molecules and ions.

iii) Relative Molecular Mass of a substance

iv) A Reducing agent

v)  A liquid acts as a drying agent

Part-B

A) 2xV.D

B) Ammonia

C) Cathode

D) Anode

E) Conc. Sulphhuric acid

F) Weak electrolyte

G) CaO

c) Select the correct answers from the words given below:                                                       5M

i)           A weak acid

A) Ammonium hydroxide  B) Acetic acid             C) Nitric acid     D) Sulphuric acid

ii)         The base used as antacid.

A) Mg(OH)₂                    B) Ca(OH)₂                    C) NaOH                 D) KOH

iii)       Ammonia gas is obtained when warm water is added to _______

A) Mg₃N₂                        B) CaO                           C) ZnS                     D) NH₄Cl

iv)       Brown ring test is used for the detection of _____

A) SO₄^2-                           B) Cl^1-                            C) NO₃^1-                   D) Na⁺

v)         Which property of Sulphuric acid helps in preparation of HCl gas?

A) Oxidising agent          B) Drying agent             C) Non-volatile        D) Dehydrating agent

d) Fill in the blanks:-                                                                                                                  5M

Sulphuric acid undergoes __________ dissociation when dissolved in water to give a _______ concentration of Hydronium ions. Hence it is a _________ electrolyte. On electrolysis it gives __________ at anode and ___________ at cathode.

(Hydrogen gas, Chlorine gas, Oxygen gas, Strong, weak, high, complete, partial)

e) Correct the following statements and rewrite.                                                                      5M

i) Lead bromide conducts electricity.

ii) Ammonia gas turns red litmus to blue.

iii) Ammonia gas dissolves in water and forms liquid Ammonia.

iv) Nitric acid reacts with Magnesium to give Hydrogen gas.

v) Sulphuric acid is dehydrating agent.

f) Select the correct word for following statements.                                                                5M

(Empirical formula, Conc.Nitric acid, Lead nitrate, Ammonia, Copper sulphate, Sulphuric acid)

i) The solution of this compound is used as the electrolyte when impure Copper is refined.

ii) The simplest ratio of the number of atoms of the elements in a given compound.

iii) The gas which burns in Oxygen with green flame.

iv) It gives reddish brown vapours and yellow residue on heating.

v) The acid used in the preparation of a non-volatile acid.

g) Fill in the blanks.                                                                                                                  5M

i) The passage of electric current through an electrolyte is due to the flow of _______ (ions/electrons)

ii) The basicity of Acetic acid is ________ (2/1/3).

iii) Ammonia gas is collected by ____________ ( downward /upward) displacement of __________ (air/water).

iv) Nitric acid is _____________ (volatile/non volatile) acid.

v) ___________( Sulphur dioxide/Oleum) dissolves in water to give Sulphuric acid.

h) A) A mixture of 300cc of Carbon monoxide and 200cc of Oxygen is ignited then find the volumes of Oxygen unused and Carbon dioxide produced.                                                                                 2M

2CO + O₂ à 2CO₂

B) Copy and Complete the following table.                                                                          3M

Cation present in the salt solution	With small amounts of NaOH	With excess NaOH solution
Ca2+
	Dirty green precipitate	insoluble
Pb2+

Section II (40 Marks)

Answer any four of the following questions

Question 2                                                                                                                             4+3+3

a)      Fill in the blanks with the suitable words.

An aqueous solution of a compound X turns blue litmus to red hence it must contain (i) __________ ions. When a piece of Zinc is added to this solution __________ gas is produced. When a base is added to the solution of X, it produces __________ and ________.

b)      Name the following

i)     The salt formed when dilute sulphuric acid is added to Copper oxide.

ii)      The acid present in vinegar.

iii)    The metal oxide which gives sodium hydroxide when dissolved water.

c)      Identify the following gases.

i)        A colourless gas which gives dense white fumes white fumes with the glass rod dipped in Conc. HCl.

ii) A pungent smelling gas which gives a white precipitate when passed into Silver nitrate solution which is soluble in Ammonium hydroxide.

iii) A greenish yellow gas which turns starch iodide to blue black.

Question 3                                                                                                                             3+3+4

a)      Name the anions present in the following salts.

i)        A solution of a salt P when treated with a dilute acid gives a suffocating gas which turns acidified K₂Cr₂O₇ to clear green.

ii)      When BaCl₂ solution is added to a salt solution Q , it gives a white precipitate which is insoluble in dil. HCl.

iii)    A salt solution of R gives a rotten egg smelling gas when dil. HCl is added.

b)      i) Calculate the percentage of water in Copper sulphate crystals. (H-1, O-16, S-32, Cu-64)

ii) Write the Empirical formulas of           A) Acetic acid             B) Butane  (C₄H₁₀)

c)      Calculate the Empirical formula of and Molecular formula of the compound whose composition is H- 12.5% and N-87.5%. V.D of the substance is 32. (At.Wt. H-1, N-14 )

Question 4

a)      Give balanced equations.                                                                                             3+4+3

i) Laboratory preparation of Ammonia gas.

ii) Reduction of Copper oxide using Ammonia gas.

iii) Reaction of Ammonia with excess Chlorine gas.

b)      i) State the catalyst and the temperature required in Haber’s process.

ii) Give reason why ammonia gas is not dried using Conc. Sulphuric acid.

iii) State your observation when in the catalytic oxidation of Ammonia in excess Oxygen.

iv) Name the oxidized product obtained when Ammonia gas reacts with Lead oxide.

c)      i) Which property of Ammonia is proved using Fountain experiment? State you observation in this experiment.

ii) How do you distinguish between a Zinc salt and a Lead salt using Ammonium hydroxide.

Question 5                                                                                                                            2+4+2+2

a) Name the gas evolved when:

i) Potassium nitrate is heated.

ii) Sulphur is treated with Conc. Nitric acid.

b) i) Write balanced equation for the laboratory preparation of Nitric acid.

     ii) State any one precaution in case (i).

     iii) Give reason why Nitric acid prepared in case (i) appears in yellow colour.

     iv) How do you remove that yellow colour from Nitric acid.

c) Write balanced equations for the following reactions.

i) Thermal decomposition of Conc. Nitric acid.

ii) Oxidation of Carbon with conc. Nitric acid.

d) i) How do you distinguish dil. Sulphuric acid from dil. Nitric acid?

     ii) State your observation when conc. Suphuric acid is added to Sugar crystals.

Question 6                                                                                                                                3+4+3

a)      Copy and complete the following table.

Name of the process	Step II	Catalyzed reaction	Catalyst and temperature
Contact process	Catalytic oxidation	(i)	(ii)

iii) Write balanced equation for the conversion of Pyro sulphuric acid to Sulphuric acid

b)      Name the following.

i) The gas produced when dil Sulphhuric acid is added to Sodium sulphide.

ii) The gas obtained when Sodium chloride is heated with conc. Sulphuric acid.

iii) The product at cathode in electrolysis of fused Lead bromide.

iv) The electrolytic process of purification of an impure metal.

c)      i) Write balanced equations at anode and cathode in the electrolysis of Copper sulphate using Copper electrodes.

ii) Give reason why the blue colour of the solution remains blue in the above electrolysis.

                                                                                                                                           

 Question 7                                                                                                                                   4+3+3

a)       If an article is to be electroplated with Nickel then state the following

i) The electrolyte                     ii) The anode

iii) The cathode                       iv) Cathode reaction

b)      Give reason why

i) Water is acidified with dil. Sulphuric acid before its electrolysis.

ii) Silver nitrate is not used as electrolyte in the electroplating with Silver.

iii) Electrolysis of fused Lead bromide is considered a redox reaction.

c)      State your observations:

i) At anode in electrolysis of fused Lead bromide.

ii) Electro refining of impure Copper metal.

iii) At cathode in electrolysis of Copper sulphate using Copper electrodes.