Extra question for acid base and salt no irrelevant ans
Answers
Answer:
The apartheid era in South African history refers to the time that the National Party led the country's white minority government, from 1948 to 1994.
Explanation:
Class 10 Science Chapter 2 Extra Questions and Answers Acids, Bases and Salts
Extra Questions for Class 10 Science Chapter 2 Acids, Bases and Salts with Answers Solutions
Extra Questions for Class 10 Science Chapter 2 Very Short Answer Type
Question 1.
Write a balanced chemical equation for the reaction between sodium carbonate and hydrochloric acid indicating the physical state of the reactants and products. [Foreign 2010]
Answer:
Na2CO3 (s) + 2HCl (ag) → 2NaCl (aq) + CO2 (g) + H2O (l)
Question 2.
During summer season, a milkman usually adds a small amount of baking soda to fresh milk. Give reason. [CBSE Sample Paper 2009]
Answer:
A milkman adds a very small amount of baking soda so as to prevent spoilage of milk. It leads to change in the pH which does not allow bacteria and enzymes to act and milk does not become sour due to fermentation.
Question 3.
What is the difference between slaked lime and lime water? [CBSE 2010]
Answer:
A suspension of Ca(OH)2 in water is called slaked lime. Water containing traces of Ca(OH)2 is called lime water.
Question 4.
Which acid is present in sour milk or curd?
Answer:
Lactic acid.
Question 5.
Why is potassium iodide added into common salt to use it as table salt?
Answer:
The iodide present in the salt prevents thyroid disorders.
Question 6.
What are the pH values of distilled water and common salt solution? [CBSE 2010]
Answer:
Both are neutral and have pH close to 7.
Question 7.
A dry pellet of a common base B, when kept in open absorbs moisture and turns sticky. The compound is also a by-product of chloralkali process. Identify B. What type of reaction occurs when B is treated with an acidic oxide? Write a balanced chemical equation for one such solution. [NCERT Exemplar]
Answer:
Dry pellets of sodium hydroxide absorb moisture and turn sticky when kept in open which is also a by-product of chloralkali process.
When sodium hydroxide is treated with an acidic oxide it produces salt and water.
Acids, Bases and Salts Class 10 Extra Questions with Answers Science Chapter 2, 1
Question 8.
Which bases are called alkalies? Give an example of an alkali. [CBSE 2009, 2010]
Answer:
Soluble bases are called alkalies. For example, sodium hydroxide (NaOH).
Question 9.
A knife, which is used to cut a fruit, was immediately dipped into water containing drops of blue litmus solution. If the colour of the solution is changed to red, what inference can be drawn about the nature of the fruit and why? [CBSE 2011]
Answer:
Since the colour of the blue litmus has changed to red, this means that the fruit juice is acidic in nature.
Question 10.
How do H+ ions exist in water?
Answer:
H+ ions in water combine with water (H2O) molecules and exist as H3O+ ion, called hydronium ion.