ICSE ICSE Class 8 - CISCE Question Bank Solutions

Write true or false for statement. Rewrite the false statement correctly.

The smallest part of an element capable of independent existence 4s called an atom.

Write true or false for statement. Rewrite the false statement correctly.

The intermolecular space in a gas is almost negligible.

Which one is a kind of matter:

1. light
2. petroleum
3. sound
4. heat

Give one example that illustrates the following characteristics of a chemical reaction:

Change in state

How do the following help in bringing about a chemical change?

pressure.

How do the following help in bringing about a chemical change?

light.

How do the following help in bringing about a chemical change?

catalyst .

How do the following help in bringing about a chemical change?

heat. 

Define catalyst.

 What are (i) positive catalysts and (ii) negative catalysts? Support your answer with one example for each of them.

Name three biochemical catalysts found in the human body.

Complete and balance the following chemical equations:

N₂ + O₂  →

Complete and balance the following chemical equations:

`"H"_2"S"` + `"CI"_2`  `→`  

Complete and balance the following chemical equations

Na + H₂ O →

Complete and balance the following chemical equations

NaCI + `AgNO_3`  `→`

Complete and balance the following chemical equations:

Zn + `"H"_2"SO"_4`  `→`

           (dil)

Complete and balance the following chemical equations:

Fe `"SO"_4`  + NaOH  `→`

   (aq.)          (aq.)

Complete and balance the following chemical equation:

\[\ce{Pb(NO3)2 ->[Heat]}\]

Complete and balance the following chemical equations:

Ba`"CI"_2`   +  `"H"_2"SO"_4`   `→`

    (aq.)           (aq.)

Fill in the blanK

 A .............is a substance which changes the rate of a chemical reaction without undergoing a chemical change.