(English Medium) ICSE Class 9 - CISCE Question Bank Solutions for Chemistry

Calculate the percentage composition of calcium nitrate [Ca = 40 , Cl = 35.5 , N = 14 , O = 16]

What causes the temporary and permanent hardness of water?

Find the percentage of mass water in Epsom salt MgSO₄.7H₂O.

What do you understand by

Soft water

What do you understand by

Hard water

What do you understand by

Temporary hard water

What do you understand by

Permanent hard water

What are the causes for:

Temporary hardness

What are the causes for

Permanent hardness

What are the advantages of soft water.

What are the advantages of hard water.

Name the substance which makes water temporarily hard

Name the substance which makes water permanently hard.

State the disadvantages of using hard water.

Explain the permutit method for softening hard water.

Explain with equation, what is noticed when permanent hard water is treated with

Slaked time

Explain with equation, what is noticed when permanent hard water is treated with Washing soda.

Why group 17 elements are highly reactive?

What is the name given to group 17 elements? Why are they called so?

Arrange the following:

Elements of group 17, in decreasing order of reactivity