Question

rust : ? : vinegar : acetic acid. complete the analogy​

Answer 1

Answer:

Why do vinegar and other acids remove rust?

The acid can dissolve rust (e.g. FeOOH

). The chemical reaction is:

3CH3COOH+FeOOH⟶Fe(CH3COO)3+2H2O

EDIT: (Fe(OAc)3

is NOT soluble in water) The acid forms a water-insoluble salt with the iron oxide, which then probably just crumbles from the rust layer and precipitates in the container.

Mind that rust also contains for example FeO(OH)3

and Fe2O3⋅nH2O

. The mechanism is the same.

Also, the acid oxidizes the upper layer of the iron under the rust to form a rust-resisting oxide-layer.

inegar contains CH3COOH (acetic acid) which reacts with rust FeOOH

:

3CH3COOH+FeOOH⟶Fe(CH3COO)3+2H2O

and Fe(CH3COO)3

(iron(III) acetate) is water soluble.

Answer 2

Answer:

rust : cleaner: vinegar: acetic acid