ALTS -Class-8 Simple Reaction & Their Types

Chalk, limestone, marble, eggshells and seashells are made of

• 1. calcium hydroxide
• 2. calcium oxide
• 3. calcium carbonate
• 4. calcium chloride

Conservation of mass is obtained when total mass of reactants is equal to total mass of

• 1. products
• 2. molecules
• 3. protons
• 4. atoms

Chemical changes are

• 1. reversible
• 2. irreversible
• 3. interchangeable
• 4. non interchangeable

If baking soda or fruit salt is mixed with vinegar, there takes place a

• 1. chemical reaction
• 2. physical reaction
• 3. transference
• 4. both 1 and 2

Burning of fossils fuel results in production of

• 1. bio gas
• 2. oxygen
• 3. carbon dioxide
• 4. nitrogen

At room temperature iron and sulphur

• 1. do no react
• 2. react
• 3. vigorously react
• 4. somehow react

If both water and carbon dioxide is given to plant it will not be able to prepare its own food in absence of

• 1. sugar
• 2. soil
• 3. sunlight
• 4. fertilizers

Melting, freezing, boiling, evaporation and condensation are all

• 1. physical change
• 2. chemical change
• 3. complex change
• 4. electrical change

Chemical change involves formation of

• 1. products
• 2. new substances
• 3. salts
• 4. water

Change which is not accompanied by formation of new substance is called a

• 1. physical change
• 2. chemical change
• 3. complex change
• 4. electrical change