KVV E-Modules

Which of the following solvents can dissolve resins?

A: Water B: Alcohol C: A and B D: None

What is a characteristic feature of the appearance of resins?

A: Always soft and opaque B: Always hard and transparent C: Hard, brittle or soft, translucent or opaque solids D: None

How do resins behave when heated?

A: They melt sharply at a specific temperature B: They do not melt at all C: They become powdery D: They soften over a range of temperatures

What is the taste and odor characteristic of most resins?

A: Always bitter and pungent B: Aromatic or bland; may be tasteless or bitter C: Sweet and pleasant D: Spicy and hot

Which chemical test for resins gives a reddish-brown precipitate with concentrated HCl?

A: HCl test B: Ferric chloride test C: NaOH test D: Acetone test

What does a brown or green color in the ferric chloride test indicate?

A: Presence of alkaloids B: Presence of phenolic groups in resins C: Presence of carbohydrates D: Presence of tannins

When resins are treated with alkali (NaOH), they form:

A: A precipitate B: An oily layer C: Soap-like emulsion D: No reaction

What happens when water is added to an alcoholic extract of resin?

A: Turbidity appears B: A clear solution forms C: The color changes to red D: A gas is released

Which of the following properties is common in many resins due to the presence of resin acids?

A: Basic nature B: Neutral pH C: Weak acidity D: Strong alkalinity

What is observed when acetone is added to a resin sample?

A: The resin turns yellow B: Complete dissolution C: Partial dissolution D: No change