Question

42 The increasing use of optical fibers for the construction of networks broadband telecommunications has led to considerable advances technology of glassmaking (...). The glasses have structure network based on a non-metal oxide, typically silica (SiO2), fused with metal oxides which act as "Network modifiers" and change the arrangement of links solid (...). The glass resists the attack of most reagents. However, the silica glass is reacted with acid hydrofluoric to form fluoro-silicate ions: (Explain your answer)

SiO2 (s) + 6HF (aq) → SiF6 2- (aq) + H3O + 2 (aq)

In the presented reaction

(A) hydrofluoric acid acts as a reducer.

(B) silicon oxide acts as oxidant.

(C) HF acts as a base Arrhenius.

(D) F- ion acts as a Lewis base.

(E) The hydronium ion acts as a Brönsted base.

Answer 1

Oxidation:

Oxidation is a process in which either 1 or all following changes occurs:

1. Gaining of oxygen atoms
2. Loss of electrons
3. Loss of hydrogen atom.
4. Increasing oxidation number.

Reduction:

Reduction is a process in which either 1 or all following changes occurs:

1. Loss of oxygen atoms
2. Gaining of electrons
3. Gaining of hydrogen atom.
4. Decreasing oxidation number.

Oxidation and reduction process are reverse process.

Oxidizing agent:

Oxidizing agent is a reactant of a reaction which causes an oxidation through accepting electron.

Reducing agent:

Reducing agent is a reactant of a reaction which causes a reduction through donating electron.

SiO2 (s) + 6HF (aq) → SiF6 2- (aq) + H3O + 2 (aq)

In the presented reaction

(A) hydrofluoric acid acts as a reducer.

Because in the above reaction hydrofluoric acid is hydrofluoric acid donating electron.

(B) silicon oxide acts as oxidant.

Because in the above reaction SiO2 is accepting electron.

Arrhenius acid-base systems: