Time Allowed: 2 Hours                                                                                                                            Maximum Marks: 80

 

• Answers to this paper must be written on the paper provided separately.
• You will not be allowed to write during 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 A is compulsory. Attempt any four questions from Section B. 
• The intended marks for questions or parts of questions are given in brackets [].

 

Section - A

Question 1

Choose the correct answers to the questions from the given options.         [15] 

(Do not copy the question, write the correct answers only.) 

(i) During the electrolysis of acidified water which of the following takes place:  P. cathode: Oxygen is released. 

Q. anode: Oxygen is released. 

R. anode: Hydrogen is released. 

S. anode: Sulphur dioxide is released. 

(A) only P

(B) only Q

(C) only R

(D) both P and Q 

 

(ii) The colour change observed when the solution of magnesium hydroxide is tested with the following indicators: 

(A) phenolphthalein turns colourless to pink. 

(B) methyl orange remains orange. 

(C) phenolphthalein remains colourless. 

(D) blue litmus solution turns red. 

 

(iii) The atomic masses of silicon (Si), nitrogen (N), and hydrogen (H) are approximately 28,14, and 2 respectively.  Which of the following statements regarding the number of atoms in 28 g of silicon, 14 g of nitrogen, and 2 g of  hydrogen is correct? 

P. 14 g of nitrogen contains seven times the number of atoms as 2 g of hydrogen. 

Q. 14 g of nitrogen contains half the number of atoms as 28 g of silicon. 

(A) only P

(B) only Q

(C) both P and Q

(D) neither P nor Q 

 

(iv) Neutral Litmus Solution is added to sodium hydrogen carbonate solution. Which of the observations  correct?

Litmus solution	Observation
P	Turns red
Q	Turns blue

(A) P

(B) Q

(C) Neither P nor Q

(D) Both

 

(v) Hydrogen chloride can be obtained by adding concentrated sulphuric acid to: 

(A) NaCl

(B) Na₂SO₄

(C) Na₂CO₃

(D) NaNO₃

 

(vi) Which apparatus could be used to electroplate an iron nail with copper?

(A)  

 

 

 

(B)

 

 

(C)

 

 

 

 

(D)

 

 

 

 

(A) P

(B) Q

(C) R

(D) S 

 

(vii) The acidity of sodium hydroxide is: 

(A) 1

(B) 2

(C) 3

(D) 4 

 

(viii)

A → A⁺¹; B → B^-2 

Number of electrons present in the outermost shell of atoms A and B respectively are: 

(A) 1, 2

(B) 1, 4

(C) 6, 2

(D) 1, 6 

 

(ix) Hydrated copper sulphate on heating changes to: 

(A) Blue and crystalline

(B) White and crystalline 

(C) Blue and amorphous

(D) White and amorphous 

 

(x) An element with atomic no.  _____________  will form a basic oxide. 

(A) 14

(B) 17

(C) 18

(D) 19 

 

(xi) Liquid NH₃ is employed in refrigerator because: 

(A) It is more basic.

(B) It is a stable hydride. 

(C) It has high dipole moment.

(D) It has high heat of evaporation. 

 

(xii) _________________ is the functional group in propanone. 

(A)   

 

(B) –OH

(C) –CHO

(D) –COOH 

 

(xiii) The process of separation of ions present in an ionic compound is called as: 

(A) Ionisation

(B) Dissociation

(C) Separation

(D) Electrolysis 

 

(xiv) The catalyst used in Haber’s process is  _____________  . 

(A) Finely divided iron

(B) Graphite

(C) Vanadium pentoxide

(D) Platinum 

 

(xv) Among the elements given below, the element with least electronegativity is: 

(A) Lithium

(B) Carbon

(C) Boron

(D) Fluorine

 

Question 2 

(i) Analyse the given diagram and answer the following questions:                [5]

 

 

 

 

 

(a) Which property of ammonia is depicted in above diagram? 

(b) What is taken in combustion tube? 

(c) Enlist your observations if the compound taken in combustion is

(a) CuO

(b) PbO. (Also give equations) 

 

(ii) Match the following Column A with Column B.

Column A	Column B
(a) Sodium chloride	1. Alkali
(b) Solder	2. Sulphide ore
(c) Bayer’s process	3. Ionic bond
(d) Roasting	4. Sodium hydrogen sulphate
(e) Acid salt	5. Electrical fuse

 

(iii) Complete the following by choosing the correct answer from the bracket:                                                                      [5] 

(a) Metals form ______________ chlorides. (covalent/ ionic) 

(b) The basicity of acetic acid is __________ (3,1,4) 

(c) _____________ (AgCl/PbCl₂), a white precipitate is soluble in excess NH₄OH. 

(d) Electrolysis of aqueous sodium chloride solution will form ___________ at the cathode. (hydrogen gas/  sodium metal) 

(e) Substitution reactions are characteristic reactions of ____________. (alkynes/alkenes/alkanes) 

 

(iv) Identify the following:                                                                                                                                                         [5]

(a) The acid which produces sugar charcoal from sugar. 

(b) The reddish-brown liquid S is dissolved in water. When ethyne gas is passed through it, turns colourless. 

(c) When barium chloride solution is added to salt solution E a white ppt. insoluble in dilute hydrochloric acid  is obtained. 

(d) An element having highest electronegativity. 

(e) A salt M on treatment with concentrated sulphuric acid produces a gas which fumes in moist air and gives  dense fumes with ammonia. 

 

(v)(a) Draw the structural diagram for the following compounds:                                                                                       [5] 

1. But-1-yne 

2. 1, 3 dichloropentane 

3. 2-propanone 

(b) Give the IUPAC name of the following organic compounds:

1.

 

 

2.

 

 

 

Section - B

Question 3 

(i) Identify the salts P and Q from the observations given below:                                                                                      [2] 

On performing the flame test 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) Why is sulphuric acid considered to be a dibasic acid?                                                                                                      [2] 

 

(iii) Arrange the following as per the instruction given in the brackets.                                                                                [3] 

(a) Li,F,N [increasing order of electronegativity] 

(b) Na,Al,Cl [increasing order of ionization potential] 

(c) Br,F,Cl [decreasing order of atomic radius]

 

(iv) (a) What is the essential difference in the nature of compounds when two combining atoms?                                    [3] 

1. Differ much in their electronegativities? 

2. Don’t differ much in their electronegativities? 

(b) A gas cylinder contains 12 × 10²⁴ molecules of oxygen gas. If Avogadro’s number is 6 × 10²³ molecules. Calculate the mass of oxygen present in the cylinder. 

 

Question 4 

(i) For the electro-refining of copper:                                                                                                                                        [2] 

(a) What is cathode made up of? 

(b) Write the reaction that takes place at the anode. 

 

(ii) A gas cylinder can hold 1 kg of hydrogen at room temperature and pressure:                                                                  [2]

(a) Find the number of moles of hydrogen present.             

(b) What weight of CO₂ can the cylinder hold under similar conditions of temperature and pressure?  (9H = 1, C = 12, O = 16) 

 

(iii) Give balanced equations for each of the following:                                                                                                           [3] 

(a) Aluminum hydroxide to alumina 

(b) Oxidation of hydrochloric acid with lead oxide. 

(c) Dehydrogenation of ethyl chloride by alc. KOH. 

 

(iv) With respect to contact process answer the following:                                                                                                   [3] 

(a) Temperature of the reaction 

(b) Catalyst used 

(c) Balanced equation for the reaction occurring 

 

Question 5 

(i) (a) Identify the gas evolved and give the chemical test in each of the following cases:                                                     [2]

Dilute hydrochloric acid reacts with sodium sulphite 

(b) State the observation:  Concentrate sulphuric acid is added to carbon. 

 

(ii) Name the alloy which is made up of:                                                                                                                                     [2] 

(a) Aluminum, Magnesium, Copper, and Manganese 

(b) Copper, Tin and Zinc 

 

(iii) Study the figure given below and answer the questions that follow:                                                                              [3]

 

 

 

 

 

(a) Identify the gas Y. 

(b) What property of gas does this experiment demonstrate? 

(c) Name another gas which has the same property and can be demonstrated through this experiment. 

 

(iv) Give reasons:                                                                                                                                                                         [3] 

(a) Hydrocarbons are excellent fuels. 

(b) Methane does not undergo addition reactions, but ethene does. 

(c) HCl gas have fume in moist air? 

 

Question 6 

(i) Name the following:                                                                                                                                                                [2] 

(a) The ore of aluminum containing its fluorine. 

(b) The most commonly used oxide ore of Iron. 

 

(ii) State one observation in the following cases:                                                                                                                    [2] 

(a) Action of concentrated nitric acid on copper. 

(b) Addition of excess ammonium hydroxide into copper sulphate solution.

 

(iii) Aqueous solution of nickel sulphate contains Ni²⁺ and SO₄^2–.                                                                                         [3] 

(a) Which ion moves towards the cathode? 

(b) What is the product at the anode? 

 

(iv) X [2,8,4] and Y [2,8,1] are two elements. Using this information complete the following:                                             [3] 

(a) ______________ is the metallic element. 

(b) Metal atoms tend to have a maximum of  ____________  electrons in the outermost shell. 

(c) ______________ is the reducing agent. 

 

Question 7 

(i) A compound made up of two elements X and Y has an empirical formula X₂Y. If the atomic weight  of X is 10 and that of Y is 5 and the compound has a vapour density 25, find the molecular formula.                                                        [3] 

 

(ii) (a) Ramesh prepared a acidic solution X that has a pH 6. How will the pH of the solution X change on  addition of the following?                                                                                                                                                                                              [3] 

1. Hydrochloric acid 

2. A solution of a base 

(b) The atomic number of an element is 12. To which group will this element belong to? 

 

(iii) The vapour density of a gas is 8. What would be the volume occupied by 24.0 g of the gas at STP?                            [4] 

 

Question 8 

(i) Give reasons why:                                                                                                                                                                        [2] 

(a) Cast iron is used to make castings. 

(b) Aluminum cannot be obtained from aluminum oxide by the blast furnace process. 

 

(ii) Draw the electron dot diagram of Ammonia.                                                                                                                       [2]

 

(iii) Give balanced equations for the following:                                                                                                                         [3]

(a) Ammonia is oxidised by a metal oxide. 

(b) Preparation of carbon tetrachloride from methane. 

(c) Action of heat on aluminium hydroxide. 

 

(iv) (a) An acid which is present in vinegar.                                                                                                                                 [3]

(b) NaOH solution when added to the solution (A) gives a reddish brown precipitate. 

(c) Strongest electrolyte – acetic acid or sulphuric acid.

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