X SA I TEST CHEMISTRY

TEST– X /SCIENCE [CHEMISTRY]

TIME:90Min.                                                                                                                                                                               M.M. 60

1.       [1]Name two metal which has low melting point.

2.       [1]Name a non-metal which is extremely hard.

3.       [1]Explain why, the surface of some metals acquires a dull appearance when exposed to air for a long time.

4.       [1]What happens when calcium reacts with water ? Write the equation of the reaction of calcium with

5.       [1]What is aqua-regia ? Can it dissolve gold metals?

6.       [2]Arrange the following metals in order of their chemical reactivity, placing the most reactive first :Magnesium, Copper, Iron, Sodium, Zinc, Lead, Calcium

7.       [2]What will happen if a strip of zinc is immersed in a solution of copper sulphate.

8.       [2]A copper coin is kept immersed in a solution of silver nitrate for some time. What will happen to the coin and the colour of the solution. Give reaction

9.       [2]Name one metal which displaces copper from copper sulphate solution and one which does not. Give reaction

10.    [2]What type of oxide are formed when non-metals combine with oxygen ? Explain with the help of an example. Is it basic or acidic? Give appropriate reaction to justify.

11.    [2]Explain why metals do not liberate hydrogen gas with dilute nitric acid. Which metals do so. Give reaction

12.    [2]Give reason for the following :

Carbonate and Sulphide ores are usually converted into oxides during the process of extraction.

13.    [2]Explain giving one example, how highly reactive metals ( which are high up in the reactivity series ) are expected.

14.    [2]How is manganese extracted from manganese dioxide MnO₂ ? Explain with the help of an equation.

15.    [2]What is a thermit reaction ? Explain with the help of an equation. State one use of this reaction.

16.    [2]What  is the brown coloured gas evolved when lead nitrate crystals  are heated in  a dry test tube  ?

17.    [2]On mixing  solutions of lead  nitrate and  potassium iodide in a test tube.                                  

(a)     Write  the chemical  equation involved in the balanced form.

(b)     What  is the colour  of the precipitate ?  Name  the precipitate.

18.     [1,1,3]What is chlor-alkali process? Write its products and their uses. ( 3 each)

19.    [3]What are amphoteric oxide ? Give examples of two amphoteric oxide.Show their reactions.( All 4

reactions)

20.    [3]Define the terms ; (i) mineral, (ii) ore, and (iii) gangue.

21.    [3]A zinc ore on heating in air forms sulphur dioxide. Describe briefly any two stages involved in the

conversion of this concentrated ore into zinc metal.

22.    [3]Compounds like alcohol and glucose also contain hydrogen but are not characterized as acids. Describe an activity to prove it.

23.    [3]Write following reactions

(a)                An acid with Metal Carbonate & Metal bi-carbonate

(b)                How to identify the gas evolved by above reactions. Write equation.

24.    [4]Write about followings:

(a)                Do metals reacts with base to evolve hydrogen gas. If yes write reaction.

(b)                What is hydronium ion ?

(c)                Do basic solutions also have H+(aq) ions? If yes ,then are these basic?

25.    [4] (a)     What  are  redox  reactions ?                                                                                                       

(b)     Why  the  reaction between Manganese dioxide and  Hydrochloric acid  is redox reaction ?

(c)     Identify the substance oxidised and  the substance reduced in the above  reaction.

26.    [5] (a)     Name  the components of the alloys  steel and  stainless steel.

(b)     Why gold  is alloyed with  copper ?

(c)     Name  a metal  which & give reaction

(i)      will react  vigorously with  cold water

(ii)     will react  with  only  hot  water

(iii)    will only  react   with   steam