MEDIUM
8th Kerala Board
IMPORTANT
Earn 100

Identify the energy change involved and write down what type of chemical reaction takes place in reaction between potassium hydroxide and sulphuric acid.

Important Questions on Chemical Changes

EASY
8th Kerala Board
IMPORTANT
Science for Class 8 - Part 1>Chapter 6 - Chemical Changes>Let us assess>Q 2
Identify the energy change involved and write down what type of chemical reaction takes place in Burning of fuels.
MEDIUM
8th Kerala Board
IMPORTANT
Science for Class 8 - Part 1>Chapter 6 - Chemical Changes>Let us assess>Q 3
A student tries to plate an iron nail with copper. Draw its arrangement by selecting the required materials from the list given below. Silver nitrate, iron nail, copper sulphate, silver rod, copper rod, silver plate, iron sulphate, battery, wire, water, beaker. 
MEDIUM
8th Kerala Board
IMPORTANT
Science for Class 8 - Part 1>Chapter 6 - Chemical Changes>Let us assess>Q 4
List out the instruments that use electrochemical cells. What are the merits and demerits of using such cells? 
MEDIUM
8th Kerala Board
IMPORTANT
Science for Class 8 - Part 1>Chapter 6 - Chemical Changes>Let us assess>Q 5
Classify the following into physical changes and chemical changes. 
1. Melting of ice.
2. Heating magnesium in water.
3. Silver bromide kept exposed to sunlight.
4. Change happening to soda water on opening its bottle.
MEDIUM
8th Kerala Board
IMPORTANT
Science for Class 8 - Part 1>Chapter 6 - Chemical Changes>Let us assess>Q 6
Give an example each for exothermic and endothermic reactions.
HARD
8th Kerala Board
IMPORTANT
Science for Class 8 - Part 1>Chapter 6 - Chemical Changes>Extended activities>Q 1
Making a volcano
Heap up some ammonium dichromate powder on a tile. Deposit on it the chemical present on a match stick, and ignite. Write down the changes happening there.
Change in colour _____
Change in amount _____
Exchange of energy ____
HARD
8th Kerala Board
IMPORTANT
Science for Class 8 - Part 1>Chapter 6 - Chemical Changes>Extended activities>Q 2
Kindling fire by pouring oil.
Heap up some potassium permanganate on a tile. Keep a piece of dry cotton wick on top of it. Pour one or two drops of glycerine on the wick. Observe the changes.
HARD
8th Kerala Board
IMPORTANT
Science for Class 8 - Part 1>Chapter 6 - Chemical Changes>Extended activities>Q 3
Take a magnesium ribbon and clean it by scrubbing. Then burn it in air. Collect the product formed and dissolve it in water. Dip litmus papers and pH paper in this solution and observe. Find out the reason for the results of the observations.