Compare the modes of action of homogeneous and heterogeneous catalysts. State one example of each type of catalysis using a chemical equation and include state symbols.

Important Questions on Materials

EASY

Diploma

IMPORTANT

Oxford IB Diploma Programme Chemistry Course Companion>Chapter 22 - Materials>Questions>Q 1

Liquid-crystal displays are used in digital watches, calculators, and laptops. Describe the liquid-crystal state, in terms of molecular arrangement, and explain what happens as temperature increases.

EASY

Diploma

IMPORTANT

Oxford IB Diploma Programme Chemistry Course Companion>Chapter 22 - Materials>Questions>Q 2

Discuss three properties a substance should have if it is to be used in liquid-crystal displays.

EASY

Diploma

IMPORTANT

Oxford IB Diploma Programme Chemistry Course Companion>Chapter 22 - Materials>Questions>Q 3

Kevlar is an example of a lyotropic liquid crystal. Outline what is meant by lyotropic liquid crystal.

EASY

Diploma

IMPORTANT

Oxford IB Diploma Programme Chemistry Course Companion>Chapter 22 - Materials>Questions>Q 4

Detergents are one example of lyotropic liquid crystals. State one other example of a lyotropic liquid crystal and describe the difference between lyotropic and thermotropic liquid crystals.

EASY

Diploma

IMPORTANT

Oxford IB Diploma Programme Chemistry Course Companion>Chapter 22 - Materials>Questions>Q 5

Name a thermotropic liquid crystal.

EASY

Diploma

IMPORTANT

Oxford IB Diploma Programme Chemistry Course Companion>Chapter 22 - Materials>Questions>Q 5

Liquid-crystal displays are used in digital watches, calculators, and laptops. Explain the liquid-crystal behaviour of the thermotropic liquid crystal named in part

(a)

, on the molecular level.

EASY

Diploma

IMPORTANT

Oxford IB Diploma Programme Chemistry Course Companion>Chapter 22 - Materials>Questions>Q 6

Describe the meaning of the term liquid crystals. State and explain which diagram in figure $11, a or b,$ represents molecules that are in a liquid crystalline phase.

Question Image