Consider the following comments about saponification reactions;�

Subject

Science

Class

CBSE Class 10

Pre Boards

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Sample Papers

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 Multiple Choice QuestionsMultiple Choice Questions

1. A student obtained a sharp image of a candle flame placed at the distant end of the laboratory table on a screen using a concave mirror to determine its focal length. The teacher suggested him to focus a distant building, about 1 km away from the laboratory, for getting more correct value of the focal length. In order to focus the distant building on the same screen, the student should slightly move the: 
  • mirror away from the screen
  • screen away from the mirror
  • screen towards the mirror
  • screen towards the mirror
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2. To determine the approximate focal length of the given convex lens by focussing a distant object (say, a sign board), you try to focus the image of the object on a screen. The image you obtain on the screen is always
  • erect and laterally inverted
  • erect and diminished
  • inverted and diminished
  • inverted and diminished
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3. Select from the following the best experimental setup for tracing the path of a ray of light passing through a rectangular glass slab.

  • P

  • Q

  • R

  • R

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4.

Study the following figure in which a student has marked the angle of incidence (<i), angle of refrcation (< r), angle of emergence (< e), angle of prism ( < A) and the angle of deviation (<D). The corrected angles are: 


  • angle straight A space and space angle straight i
  • angle straight A comma space angle straight i space and space angle straight r
  • angle straight A comma space angle straight i comma space angle straight e space and space angle straight D
  • angle straight A comma space angle straight i comma space angle straight e space and space angle straight D
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5.

Which of the following sets of materials can be used for conducting a saponification reaction for the preparation of soap?

  • Ca(OH)2 and neem oil 

  • NaOH and neem oil

  • NaOH and mineral oil. 

  • NaOH and mineral oil. 

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6.

A student takes four test tubes marked P, Q, R and S of 25 mL capacity and fills 10 mL of distilled water in each. He dissolves one spoon full of four different salts in each as − KCl in P, NaCl in Q, CaCl2 in R and MgCl2 in S . He then adds 2 ml of a sample of soap solution to each of the above test tubes. On shaking the contents of each of the test tubes, he is likely to observe a good amount of lather (Foam) in the test tubes marked. 

  • P and Q

  • R and S

  • P, Q and R

  • P, Q and R

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7.

Consider the following comments about saponification reactions; 
I. Heat is evolves in these reactions.
II. For quick precipitation of soap, sodium chloride is added to the reaction mixtures. 
III. Saponification reactions are a special kind of neutralization reactions.
IV. Soaps are basic salts of long-chain fatty acids

  • I, II and III

  • II, III and IV

  • I, II and IV

  • I, II and IV


C.

I, II and IV

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8.

A student has to perform the experiment " To identify the different parts of an embryo of an embryo of a dicot seed. "

  • Pea, gram, wheat

  • Red kidney bean, maize, gram 

  • Maize, wheat, red kidney bean

  • Maize, wheat, red kidney bean

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9.

Which of the following is a correct set of homologous organs?

  • Forelimbs of a frog, bird and lizard

  • Spine of cactus and thorn of Bougainvillea

  • Wings of bat and wings butterfly

  • Wings of bat and wings butterfly

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 Multiple Choice QuestionsShort Answer Type

10.

Write the next homologue of each of the following:
i) C2H4
ii) C4H6

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