MEDIUM
8th CBSE
IMPORTANT
Earn 100
The bleaching action of bleaching powder is due to the formation of
40% studentsanswered this correctly
Important Questions on Some Important Elements and their Compounds
EASY
8th CBSE
IMPORTANT
Which among the following types of glass is used in the manufacture of doors and windows of automobiles?
EASY
8th CBSE
IMPORTANT
Which of the following plastics can be recycled?
HARD
8th CBSE
IMPORTANT
Two moist red roses are taken in two containers A and B into which an anhydride of sulphurous acid and a greenish-yellow coloured gas are passed, respectively. What changes are observed with respect to two roses in A and B? How do you account for these changes?
MEDIUM
8th CBSE
IMPORTANT
Among white phosphorous and red phosphorous which is preferable for use in match sticks? Give
a reason in support of your answer.
MEDIUM
8th CBSE
IMPORTANT
When a burning paraffin candle is introduced into two jars containing oxygen and chlorine gases separately, what observations can be made? Explain with appropriate reasons.
HARD
8th CBSE
IMPORTANT
When chlorine reacts with hot and concentrated caustic alkali XOH, one of the products, Y is formed by this reaction is used as an oxidiser in the match industry. Identify the compound Y and the element X.
MEDIUM
8th CBSE
IMPORTANT
Two samples of sulphur are heated separately starting at . One sample is found to melt at and the other one melts at . How do you account for this?
MEDIUM
8th CBSE
IMPORTANT
Bone ash contains both micro and macronutrients in it. However, it is not used as a fertiliser. It is converted to superphosphate of lime which is an important fertiliser. Justify.
