Neck masses are common in adults, but the underlying cause is not always easily identified. This guideline is an important instrument for the early diagnosis and treatment of potentially malignant growths, especially with the rise of HPV-related head and neck cancer.
It is easily produced by igniting a mixture of zinc and sulfur. Since zinc sulfide is insoluble in water, it can also be produced in a precipitation reaction. Solutions containing Zn 2+ salts readily form a precipitate ZnS in the presence of sulfide ions (e.g., from H 2 S). Zn 2+ + S 2â â ZnS. This reaction is the basis of a gravimetric analysis for zinc.
Sulfur and iron: since this is a mixture, the sulfur retains its properties (its yellow color, for example), and the iron retains its properties (its black color, for example). These properties can be used to separate the two elements. For iron sulfide, two elements (sulfur and iron) are heated together so that they form the compound iron sulfide. Although iron sulfide contains both sulfur and iron, it is not a mixture: it is a pure substance. Both the sulfur and the iron have âgiven upâ their individual properties to become a compound.