REMOVING INSOLUBLE IMPURITIES

Q1. Which method is used first to settle heavy particles at the bottom of a container?

• A. Filtration

• B. Sedimentation

• C. Decantation

• D. Evaporation

Q2. What is the purpose of decantation?

• A. To boil water

• B. To allow solids to settle

• C. To pour out clear water without disturbing the settled particles

• D. To add chemicals to water

Q3. Which process uses filter paper to separate dirt from water?

• A. Sedimentation

• B. Decantation

• C. Filtration

• D. Chlorination

Q4. Mira used filtration after sedimentation and found no change in pH. What does this mean?

• A. The filter is broken

• B. Filtration removes particles, not dissolved acids

• C. The water is not safe

• D. She used the wrong method

Q5. If filtration doesn’t remove a strange taste in water, what could be the reason?

• A. The filter paper was wet

• B. The water was too cold

• C. The impurity is a dissolved substance like a chemical

• D. The filter was too strong

Q6. You are given muddy water with a pH of 4. You perform sedimentation and decantation, but the pH remains the same. What should be your next step to improve both clarity and pH?

• A. Use boiling

• B. Filter it and add a mild base like baking soda

• C. Add more mud

• D. Leave it in sunlight

Q7. What would happen if you skip sedimentation and directly use filtration on very muddy water?

• A. Water becomes clean faster

• B. Filter paper gets clogged quickly and slows down the process

• C. Filter paper becomes acidic

• D. pH increases quickly