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

Balance the following important equation:

Cu + HNO₃ (conc.) → Cu(NO₃)₂ + H₂O + NO₂ 

Balance the following important equation:

C + H₂SO₄ (conc.) → CO₂ + H₂O + SO₂ 

Balance the following important equation:

S + H₂SO₄ (conc.) → SO₂ + H₂O 

Balance the following important equation:

Cu + H₂SO₄ (conc.) → CuSO₄ + H₂O + SO₂  

What causes the temporary and permanent hardness of 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

Name the substance which makes water temporarily hard

Name the substance which makes water permanently hard.

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

Slaked time

Consider the following elements: Be, Li, Na, Ca, K. Name the elements of (a) same group (b) same period.

What is meant in the periodic table by a group?

What are the following group known as?

Group 1

What are the following group known as?

Group 17

What are the following group known as?

Group 18 

Name two elements of each group.

How do atomic structures (electron arrangements) change in a period with an increase in atomic numbers moving left to right?

What happens to the number of valence electrons in atoms of elements as we go down a group of the periodic table?