How do you write equation for Acids?

Question

There were several reactions that I made all involving the use of HCl. For example, NaNO2 + HCl, NaNO3 + HCl, and FeS + HCl. What product forms from these types of reactions involving this strong acid, HCl? How do I know when H2O or CO2 forms due to the use of acid?

I understand that an acid and a base gives a neutralization reaction, which leaves behind a salt. I'm not quite sure what happens with all others. Please don't just give me an answer, but, I need a concise explanation as well.

There were several reactions that I made all involving the use of HCl. For example, NaNO2 + HCl, NaNO3 + HCl, and FeS + HCl. What product forms from these types of reactions involving this strong acid, HCl? How do I know when H2O or CO2 forms due to the use of acid?

I understand that an acid and a base gives a neutralization reaction, which leaves behind a salt. I'm not quite sure what happens with all others. Please don't just give me an answer, but, I need a concise explanation as well.

EDIT: Thanks Dafreakz. What would something like FeS + HCl give me then? FeS + HCl --> H2 + ??

Answer 1

acid + carbonates ---> salt + CO2 + H2O
eg: 2HCl + Na2CO3 ---> 2NaCl + CO2 + H2O
HCl + NaHCO3 ---> NaCl + CO2 + H2O
>only carbonates give out CO2

acid + metal ---> H2 + salt
eg: HCl + Zn ---> ZnCl2 + H2

acid + ammonia ---> ammonium salt
eg: HCl + NH3 ---> NH4Cl

Answer 2

NaNO2 + HCl -> HNO2 + HCl

NaNO3 + HCl (No reaction)

FeS + 2 HCl -> H2S + FeCl2

NaNO2, NaNO3, FeS are actually salts of NaOH or Fe(OH)2 with HNO2, HNO3 or H2S

As HNO3 is stronger than HCl, it is not generated.

Answer 3

Nomenclature
In the classical naming system, acids are named according to their anions. That ionic suffix is dropped and replaced with a new suffix (and sometimes prefix), according to the table below. For example, HCl has chloride as its anion, so the -ide suffix makes it take the form hydrochloric acid. In the IUPAC naming system, "aqueous" is simply added to the name of the ionic compound. Thus, for hydrogen chloride, the IUPAC name would be aqueous hydrogen chloride.

Classical naming system:

Anion Prefix Anion Suffix Acid Prefix Acid Suffix Example
per ate per ic acid perchloric acid (HClO4)
ate ic acid chloric acid (HClO3)
ite ous acid chlorous acid (HClO2)
hypo ite hypo ous acid hypochlorous acid (HClO)
ide hydro ic acid hydrochloric acid (HCl)


Chemical characteristics
In water the following equilibrium occurs between a weak acid (HA) and water, which acts as a base:

HA(aq) + H2O ⇌ H3O+(aq) + A-(aq)

The acidity constant (or acid dissociation constant) is the equilibrium constant for the reaction of HA with water:


Strong acids have large Ka values (i.e. the reaction equilibrium lies far to the right; the acid is almost completely dissociated to H3O+ and A-). Strong acids include the heavier hydrohalic acids: hydrochloric acid (HCl), hydrobromic acid (HBr), and hydroiodic acid (HI). (However, hydrofluoric acid, HF, is relatively weak.) For example, the Ka value for hydrochloric acid (HCl) is 107.

Weak acids have small Ka values (i.e. at equilibrium significant amounts of HA and A− exist together in solution; modest levels of H3O+ are present; the acid is only partially dissociated). For example, the Ka value for acetic acid is 1.8 x 10-5. Most organic acids are weak acids. Oxoacids, which tend to contain central atoms in high oxidation states surrounded by oxygen may be quite strong or weak. Nitric acid, sulfuric acid, and perchloric acid are all strong acids, whereas nitrous acid, sulfurous acid and hypochlorous acid are all weak.

Note on terms used:

The terms "hydrogen ion" and "proton" are used interchangeably; both refer to H+.
In aqueous solution, the water is protonated to form hydronium ion, H3O+(aq). This is often abbreviated as H+(aq) even though the symbol is not chemically correct.
The strength of an acid is measured by its acid dissociation constant (Ka) or equivalently its pKa (pKa= - log(Ka)).
The pH of a solution is a measurement of the concentration of hydronium. This will depend on the concentration and nature of acids and bases in solution.

Polyprotic acids
Polyprotic acids are able to donate more than one proton per acid molecule, in contrast to monoprotic acids that only donate one proton per molecule. Specific types of polyprotic acids have more specific names, such as diprotic acid (two potential protons to donate) and triprotic acid (three potential protons to donate).

A monoprotic acid can undergo one dissociation (sometimes called ionization) as follows and simply has one acid dissociation constant as shown above:

HA(aq) + H2O(l) ⇌ H3O+(aq) + A−(aq) Ka
A diprotic acid (here symbolized by H2A) can undergo one or two dissociations depending on the pH. Each dissociation has its own dissociation constant, Ka1 and Ka2.

H2A(aq) + H2O(l) ⇌ H3O+(aq) + HA−(aq) Ka1
HA−(aq) + H2O(l) ⇌ H3O+(aq) + A2−(aq) Ka2
The first dissociation constant is typically greater than the second; i.e., Ka1 > Ka2 . For example, sulfuric acid (H2SO4) can donate one proton to form the bisulfate anion (HSO4−), for which Ka1 is very large; then it can donate a second proton to form the sulfate anion (SO42−), wherein the Ka2 is intermediate strength. The large Ka1 for the first dissociation makes sulfuric a strong acid. In a similar manner, the weak unstable carbonic acid (H2CO3) can lose one proton to form bicarbonate anion (HCO3−) and lose a second to form carbonate anion (CO32−). Both Ka values are small, but Ka1 > Ka2 .

A triprotic acid (H3A) can undergo one, two, or three dissociations and has three dissociation constants, where Ka1 > Ka2 > Ka3 .

H3A(aq) + H2O(l) ⇌ H3O+(aq) + H2A−(aq) Ka1
H2A−(aq) + H2O(l) ⇌ H3O+(aq) + HA2−(aq) Ka2
HA2−(aq) + H2O(l) ⇌ H3O+(aq) + A3−(aq) Ka3
An inorganic example of a triprotic acid is orthophosphoric acid (H3PO4), usually just called phosphoric acid. All three protons can be successively lost to yield H2PO4−, then HPO42−, and finally PO43− , the orthophosphate ion, usually just called phosphate. An organic example of a triprotic acid is citric acid, which can successively lose three protons to finally form the citrate ion. Even though the positions of the protons on the original molecule may be equivalent, the successive Ka values will differ since it is energetically less favorable to lose a proton if the conjugate base is more negatively charged.


Neutralization
Neutralization is the reaction between an acid and a base, producing a salt and water; for example, hydrochloric acid and sodium hydroxide form sodium chloride and water:

HCl(aq) + NaOH(aq) → H2O(l) + NaCl(aq)
Neutralization is the basis of titration, where a pH indicator shows equivalence point when the equivalent number of moles of a base have been added to an acid. It is often wrongly assumed that neutralization should result in a solution with pH 7.0, which is only the case with similar acid and base strengths during a reaction.