MEDIUM
8th CBSE
IMPORTANT
Earn 100

Bleaching powder in cold water is an excellent bleaching agent. But it cannot act as a good bleaching agent when dissolved in hot water. Why? 

Important Questions on Some Important Elements and their Compounds

MEDIUM
8th CBSE
IMPORTANT
Pearson IIT Foundation Chemistry>Chapter 7 - Some Important Elements and their Compounds>PRACTICE QUESTIONS (COMPETITION WING)>Q 81
Hydrofluoric acid cannot be stored in glass bottles like all other acids. Give a reason. 
MEDIUM
8th CBSE
IMPORTANT
Pearson IIT Foundation Chemistry>Chapter 7 - Some Important Elements and their Compounds>PRACTICE QUESTIONS (COMPETITION WING)>Q 82
Certain phosphates are helpful in making hard water soft. Which phosphates are used and how do they help in making water soft? 
MEDIUM
8th CBSE
IMPORTANT
Pearson IIT Foundation Chemistry>Chapter 7 - Some Important Elements and their Compounds>PRACTICE QUESTIONS (COMPETITION WING)>Q 83
Both H2SO4 and HNO3 cause damage to the skin when the skin comes in contact with them. Compare and contrast the reasons. 
HARD
8th CBSE
IMPORTANT
Pearson IIT Foundation Chemistry>Chapter 7 - Some Important Elements and their Compounds>PRACTICE QUESTIONS (COMPETITION WING)>Q 84
Nitric acid attacks all the metals except noble metals but the nature of products of the same metal along with corresponding nitrates depends upon the concentration of HNO3. Explain.