Question

___________________ is the most reactive of drier metals and is generally regarded as a surface drier.

(a) Litharge

(b) Cobalt

(c) Red lead

(d) Magnesium

I have been asked this question during an online exam.

I'd like to ask this question from Types of Paints topic in section Painting, Varnishing, Distempering, etc of Construction & Building Materials

Answer 1

Right choice is (b) Cobalt

Explanation: Cobalt is widely used as the only additive in thin film paint formulations. Lead is less reactive than Cobalt has increasing restrictions in its application because of ecological requirements. Numerous of other metals, including cerium and vanadium, have been used occasionally and are effective driers.