MEDIUM
10th CBSE
IMPORTANT
Earn 100

Rajesh was given a substance and asked to identify it. He conducted three tests on the substance and recorded the results below. (P) It releases carbon dioxide, water, and a sodium salt on heating with water. (Q) It turns universal indicator greenish-blue. (R) It can be prepared from ammonia as a raw material.

What substance was Rajesh given?

Important Questions on Acids, Bases and Salts

EASY
10th CBSE
IMPORTANT
Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 21

Rajesh was given a substance and asked to identify it. He conducted three tests on the substance and recorded the results below. (P) It releases carbon dioxide, water, and a sodium salt on heating with water. (Q) It turns universal indicator greenish-blue. (R) It can be prepared from ammonia as a raw material.

Give one use of the substance based on the properties mentioned in P and Q.

MEDIUM
10th CBSE
IMPORTANT
Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 22

Rajesh was given a substance and asked to identify it. He conducted three tests on the substance and recorded the results below. (P) It releases carbon dioxide, water, and a sodium salt on heating with water. (Q) It turns universal indicator greenish-blue. (R) It can be prepared from ammonia as a raw material.

Rajesh later read that recrystallisation of the sodium salt formed in P gives another basic salt that is used in manufacture of borax.

Identify the sodium salt formed in P.

MEDIUM
10th CBSE
IMPORTANT
Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 23
Aditi finds that a mixture of an acid and a base does not change the colour of either red or blue litmus paper. Compare the amounts of H+ and OH-in the solution. 
HARD
10th CBSE
IMPORTANT
Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 24
pH is measured on a scale of 0 to 14, with lower values indicating high hydrogen ion concentration (more acidic) and higher values indicating low hydrogen ion concentration (less acidic). A pH of 7 is considered as neutral. Every whole unit in pH represents a ten-fold increase in or decrease in hydrogen ion concentration. What would the hydrogen ion concentration of a solution of pH 4 be compared to a solution of pH 8? 
HARD
10th CBSE
IMPORTANT
Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 26
Dipti has three flasks containing dilute hydrochloric acid, dilute sulphuric acid and dilute sodium hydroxide respectively. The flasks are not labelled, and she does not have any pH indicator. 
(a) Which of the solutions will she be able to identify just by making mixtures of pairs of the substances. 
(b) What observation will help her to make this identification? 
HARD
10th CBSE
IMPORTANT
Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 27
Which one of the following is the correct method of finding the pH of a solution?
HARD
10th CBSE
IMPORTANT
Science Textbook of Competency Based Questions for Class X>Chapter 2 - Acids, Bases and Salts>Exercise>Q 28
Bottle A contains acetic acid and bottle B contains sodium carbonate solution. When pH paper is dipped in each of the solution, the colour seen in A and B respectively will be:
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