What is the colour of phenolphthalein in the acidic medium?

Important Questions on Atomic Structure; Physical and Chemical Properties of Matter

EASY

9th West Bengal Board

IMPORTANT

PHYSICAL SCIENCE & ENVIRONMENT CLASS 9>Chapter 4 - Atomic Structure; Physical and Chemical Properties of Matter>EXERCISE>Q 3

What is the colour of phenolphthalein in the alkaline medium?

MEDIUM

9th West Bengal Board

IMPORTANT

PHYSICAL SCIENCE & ENVIRONMENT CLASS 9>Chapter 4 - Atomic Structure; Physical and Chemical Properties of Matter>EXERCISE>Q 4

Acetic acid is a monobasic acid. Explain.

HARD

9th West Bengal Board

IMPORTANT

PHYSICAL SCIENCE & ENVIRONMENT CLASS 9>Chapter 4 - Atomic Structure; Physical and Chemical Properties of Matter>EXERCISE>Q 5

Starting from sulphur how will you prepare ${\mathrm{H}}_2{\mathrm{SO}}_4$(give reactions only)?

MEDIUM

9th West Bengal Board

IMPORTANT

PHYSICAL SCIENCE & ENVIRONMENT CLASS 9>Chapter 4 - Atomic Structure; Physical and Chemical Properties of Matter>EXERCISE>Q 6

Give two examples of practical applications of neutralisation.

HARD

9th West Bengal Board

IMPORTANT

PHYSICAL SCIENCE & ENVIRONMENT CLASS 9>Chapter 4 - Atomic Structure; Physical and Chemical Properties of Matter>EXERCISE>Q 7

Why the mass of washing soda decreases when exposed to air?

HARD

9th West Bengal Board

IMPORTANT

PHYSICAL SCIENCE & ENVIRONMENT CLASS 9>Chapter 4 - Atomic Structure; Physical and Chemical Properties of Matter>EXERCISE>Q 8

Phosphorous is a dibasic acid, although it contains three hydrogen atoms. Explain.

EASY

9th West Bengal Board

IMPORTANT

PHYSICAL SCIENCE & ENVIRONMENT CLASS 9>Chapter 4 - Atomic Structure; Physical and Chemical Properties of Matter>EXERCISE>Q 9

Give one example of tetrabasic acid.

HARD

9th West Bengal Board

IMPORTANT

PHYSICAL SCIENCE & ENVIRONMENT CLASS 9>Chapter 4 - Atomic Structure; Physical and Chemical Properties of Matter>EXERCISE>Q 10

What are acid anhydrides? Give an example of a mixed acid anhydride.