Basic HTML Version

|  | Table of Contents |  | View Full Version

Page 62 - CT&AI_CLasa_7_Part_1
P. 62

    6.  Which step  helps confirm a substance  is
                         neutral?                   (Decomposition)

                                (a)  Test with only red litmus paper.

                                (b)  Test with only blue litmus paper.
                                                                                 3.  Filtering the rose   4.  Putting the
                                (c)   Test with both red and blue litmus           water extract          crushed petals in
                                                                                                          hot water
                                   papers.
                                                                              Identify  the  correct  sequence  of steps  that
                                (d)  Heat the substance strongly.             should be followed to prepare the indicator.
                                                                                                    (Algorithmic Thinking)
                      7.  Three unknown liquids A, B, and C are tested              (a)  2   1   4   3
                         using  blue  litmus,  red litmus,  and onion
                         indicator. The observations are shown below:               (b)  2   1   3   4

                             Test        A         B          C                     (c)  1   3   2   4

                          Blue litmus   Red    No change No change                  (d)  2   3   1   4

                          Red litmus No change    Blue    No change        9.  Which algorithm best represents neutralisation?

                          Onion smell  Same    Disappears   Same                                    (Algorithmic Thinking)

                         Which liquid is neutral?   (Decomposition)                 (a)  Acid + Acid   Salt

                                (a)  A                                              (b)  Base + Base   Water

                                (b)  B                                              (c)  Acid + Base   Salt + Water + Heat

                                (c)  C                                              (d)  Acid + Base   Base

                                (d)  Both A and B                         10.  Choose  the  correct  algorithm  to  test  a
                                                                              substance using litmus:
                      8.  A  student  wants  to  prepare  an  acid-base
                         indicator  using  red rose petals.  Some  steps                            (Algorithmic Thinking)
                         are shown below:                                           (a)   Take substance   Add water
                                                                                       Heat

                                                                                    (b)  Take litmus   Add substance
                                                                                       Observe colour change

                                                                                    (c)  Mix substances   Wait   Smell
                              1.  Crushing the      2.  Washing the
                                petals                rose petals                   (d)  Taste   Observe   Record

                    60         Computational Thinking-7 (Science)

| 57 58 59 60 61 62 63 64 65 66 67 |