Chemical reactions

Reaction of sulfur with acids

Sulfur does not react with dilute non-oxidizing acids, under normal conditions.

Sulfur reacts with hot concentrated sulfuric acid, forming SO2 [5]:

S(s) + H2SO4(l) 3 SO2(g) + 2 H2O(l)

Disulfide ions reacts with acid forming hydrogen sulfide and free sulfur [5]:

S22−(aq) + 2 H+(aq) H2S(g) + S(s)

The sulfur precipitates as a fine white powder in the water, called milk of sulfur.

Reaction of sulfur with air

Sulfur reacts with oxygen forming sulfur dioxide and trioxide [5]:

S(s) + O2(g) SO2(g)
2 SO2(g) + O2(g)
2 SO3(g)

Reaction of sulfur with bases

Sulfur reacts with hot aqueous potassium hydroxide, KOH, forming potassium sulfide and thiosulfate:

S8(s) + 12 KOH(aq) 4 K2S(aq) + 2 K2S2O3(aq) + 6 H2O(l)

Reaction of sulfur with carbon

Carbon reacts with sulfur at high temperatures, in the absense of oxygen, forming carbon disulfide [5]:

C(s) + 2 S(s) CS2(g)

Reaction of sulfur with halogens

Sulfur reacts with excess fluorine forming sulfur(VI)fluoride [5]:

S(s) + 3 F2(g) SF6(s)

Sulfur reacts with excess chlorine forming sulfur(I)chloride and sulfur(II)chloride [5]:

2 S(s) + Cl2(l) S2Cl2(s)
S(s) + Cl2(g) SCl2(s)

Sulfur reacts with excess bromine forming sulfur(I)bromide [5]:

2 S(s) + Br2(l) S2Br2(s)

Sulfur does not react with iodine [5]

Reaction of sulfur with hydrogen

Sulfur reacts with hydrogen, forming hydrogen sulfide [5]:

S8(s) + 8 H2(g) 8 H2S(g)

Reaction of sulfur with metals/metal ions

In gaseous form, Cd and S8 reacts forming CdS. At 130-180 °C solid Cd and S8 reacts explosively, also forming CdS [5].

Cd(g) + S8(g) CdS(g)
Cd(s) + S8(s) CdS(s) [yellow]

Gallium reacts with sulfur forming gallium sulfide [5]:

16 Ga(s) + 3 S8(s) 8 Ga2S3(s)

When heated, lead reacts with sulfur [5]:

Pb(s) + S(s) PbS(s)

Mercury reacts with sulfur, forming mercury(II) sulfide [5]:

Hg(l) + S(s) HgS(s)

Sodium reacts with sulfur forming sodium sulfide [5]:

16 Na(s) + S8(s) 8 Na2S(s)

Reaction of sulfur with water

Sulfur does not react with water under normal conditions.

Quantitative analysis

Method - Inductively Coupled Plasma Method [1]. A portion of the sample is digested in a combination of acids. The digest is aspirated into an 8,000 K argon plasma where resulting light emission is quantified for 30 elements simultaneously.

Method limit of detection in water = 0.002 mg/L
Method limit of detection in soil = 1.00 mg/kg