A major portion of the carbohydrates produced by plants is stored in different parts of the plant (storage organs). Explain the mechanism by which this stored food is made available when different organs need it for growth.

Important Questions on Acids, Bases and Salts

HARD

10th CBSE

IMPORTANT

Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 29

In slaking of lime, lime reacts vigorously with water to form lime water with releasing heat. Which statement(s) is/are true about the reaction?
(i) it is an endothermic reaction
(ii) it is an exothermic reaction
(iii) the pH of resulting solution is <

7

(iv) the pH of resulting solution is >

7

HARD

10th CBSE

IMPORTANT

Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 30

A student was given three solutions marked X, Y and Z, and asked to arrange them in the increasing order of their pH values. The student put two drops of each solution on three strips of universal indicator paper separately. The colours shown by the three indicator strips are as follows:
Question Image

Which of the following gives the correct order of increasing pH values.

HARD

10th CBSE

IMPORTANT

Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 31

A student added blue litmus solution to a colourless aqueous solution. The solution turned red. Which one of the following chemicals should be added in excess so that the change in colour is reversed?

HARD

10th CBSE

IMPORTANT

Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 37

Equal lengths of magnesium ribbons are taken in test tubes