CAT 2 Grade 6 DCS

Which change is called reversible change?

• Physical change

• Chemical change

• Both of them

• None of it

Physical change is a change in which:

• texture, shape and state change

• new substance is formed

• the weight of a substance is altered

• energy is exchanged

What colour does a red litmus paper turn when added to an alkali?

• Red

• Blue

• Green

• Remains the same

What colour does a blue litmus turn when added to an acid?

• Red

• Green

• Blue

• Yellow

What happens to the pH of pure water when a lemon is squeezed into it?

• pH increases from 7

• pH does not change

• pH decreases from 7

• none of them

What does this hazard symbol mean?

• toxic

• corrosive

• falmmable

• explosive

According to the pH range, which substance is slightly alkaline?

• pure water

• lemon

• tomato

• egg

Acids and alkalis are called chemically opposite because:

• acid produces Hydrogen and alkali accepts it.

• they cancel each other out

• both of these

• none of these

A chemical reaction where an acid react with an alkali is called:

• factorization

• neutralization

• evaporation

• condensation

Identify the hazardous symbol.

• power and gratitude towards life

• You are safe

• can cause death or poisoning

• No danger