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Subject :NSO    Class : Class 7

The ash which is collected after burning of magnesium ribbon is dissolved in water to give a solution X. What is the nature of the solution X when it is tested with indicators?

A It turns blue litmus red and phenolphthalein pink, hence it is an acidic solution.
B It turns red litmus blue and phenolphthalein pink, hence it is a basic solution.
C It turns blue litmus red and gives no colour with phenolphthalein, hence it is an acidic solution.
D It does not change colour of red or blue litmus and phenolphthalein, hence it is a neutral solution.


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Subject :NSO    Class : Class 2

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Subject :NSO    Class : Class 7

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Subject :NSO    Class : Class 5

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Subject :NSO    Class : Class 7

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Subject :NSO    Class : Class 7

Match the given chemical reactions with the products listed in the box and select the correct option from the given codes.


P. Mixing magnesium oxide with water
Q. Brown deposit on iron nail kept in copper sulphate solution
R. Carbon dioxide is passed through lime water
S. Absorption of ultraviolet radiations by ozone.

AP-(v), Q-(vii), R-(i), S-(vi)
BP-(iv), Q-(ii), R-(i), S-(iii)
CP-(ii), Q-(iii), R-(viii), S-(vii)
DP-(ii), Q-(iv), R-(viii), S-(vi)


Ans 1:

Class : Class 7

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Subject :NSO    Class : Class 5

Priyanka sprayed 2 pieces of bread with water and put each into a plastic bag. She sealed the bags tightly. Then she put one bag into the freezer and the other was left on a table near the kitchen window. 5 days later, she took the bag out of the freezer and compared it to the one on the table. The given figure shows what she saw.

Which of the following was Priyanka trying to find out ?

AMould requires air to grow.
BMould requires dryness to grow.
CMould requires water to grow.
DMould requires warmth to grow.


d

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Subject :NSO    Class : Class 9

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Subject :NSO    Class : Class 1

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Subject :NSO    Class : Class 6

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