Why can only nitric acid react with copper metal and not HCl? If they are the same Molar concentration, they both contain free Hydronium ions so both
should be able to break the bonds of the copper metal and produce Cu+ ions (dissolving the copper). I suppose this question can apply to why
hydrofluoric acid dissolves glass and sulfuric acid doesn't.
So is the NO3- ion a key factor in the copper reaction and the F- is what eats at the glass?
plante1999 - 16-2-2014 at 10:11
copper electrode potential is higher then hydrogen, so any acid that rely solely on hydrogen ion can't dissolve it. It must also use oxidizing agent.
Some metal are so noble that in plus of an oxidizing agent, they need a complexing one.
It is another storry for glass stuff.Chemosynthetic - 16-2-2014 at 12:18
Additional properties for acid/base reactivity deal with linear combinations of atomic orbitals forming molecular orbitals and overlap, which is often
grossly simplified down to the useful dichotomy of soft/hard acids and bases.Brain&Force - 16-2-2014 at 12:36
Nitric acid acts as an oxidizer, especially in concentrated solution, partially due to the formation of NO2+.
Hydrofluoric acid reacts with glass by complexing with the central Si atom. The following reaction takes place:
6HF + SiO2 → H2SiF6 + 2H2O
assuming that the glass is pure quartz glass; boron and others can alter the reaction.
In general, hydrochloric acid is nonoxidizing (potassium permanganate can reduce it to chlorine) but highly coordinating with many transition metals.
Sulfuric acid is probably the closest to an ideal acid at high concentration, nitric is also ideal at a low concentration. As for other strong acids
(like sulfamic or triflic acids), I don't know much about them.plante1999 - 16-2-2014 at 12:38
In general, hydrochloric acid is nonoxidizing (potassium permanganate can reduce it to chlorine)
Permanganate oxidize the reducing hydrochloric acid... as does manganese dioxide, hypochlorite, and so on.Turner - 16-2-2014 at 13:14
What classifies as an oxidizing agent? I know that carbon can be oxidized to CO2, I know that potassium nitrate is an "oxidizer" because it releases
oxygen when it decomposes. But I have read Sulfur is an oxidizer, and copper can be "oxidized" by acetic acid?plante1999 - 16-2-2014 at 13:19
Copper can't be oxidized by acetic acid ha ha.
Oxidizing power is the ability to gain electron from other material, generally quite brutally.Brain&Force - 16-2-2014 at 14:02
Reducers give electrons, oxidizers receive them. But remember that oxidizers are reduced and reducers are oxidized!
Carbon is a reducing agent, oxygen is an oxidizing agent, and together they make carbon dioxide. Potassium nitrate is an oxidizer because it can
donate electrons, not because it decomposes to oxygen. Oxidizers do not imply oxygen in their composition - the halogens are strong oxidizers, but do
not contain oxygen (they are elements). Sulfur can act as an oxidizer by accepting two electrons to form a -2 state (or a -1 state for disulfides).
But it tends to reduce oxygen to form sulfur oxides.
Generally, atoms in high oxidation states are oxidizers and those in low oxidation states are reducers.
[edit: I REALLY ruined that.]
[Edited on 16.2.2014 by Brain&Force]Turner - 16-2-2014 at 14:15
Hmmm.. Then why is O2 an oxidizing agent?
C + O2 ---> CO2
How could I discern that O2 is giving electrons to Carbon in this reaction?
Also you say sulfur is an oxidizing agent by accepting two electrons, but before you said oxidizers give electrons.plante1999 - 16-2-2014 at 14:18
He messed it up, oxidizer take electrons.Zyklon-A - 16-2-2014 at 14:20
@Brain&Force, No, oxidizers take electrons, and oxygen is the second strongest oxidizer. Fluorine is the strongest, in other words, oxygen can
take electrons from any element except fluorine and most of the noble gasses. Sulfur is sometimes considered an oxidizer, because it can take
electrons from some elements. The better an element is at taking electrons, the more electronegative it is. Sulfur has an electronegativity of 2.58;
oxygen: 3.44; fluorine: 3.98. This is one reason why elements with high electronegativitys and low electronegativitys tend to not be found in their
elemental form, because give or take electrons very easily, thus forming compounds. An exception is of course oxygen. (Although most of the earths
oxygen is in compounds.)
[edit] plante1999, Looks like you beat me to it.
