The Brown Ring Complex Compound is Formulated as [Fe (H2O)5 NO]SO4. The oxidation state of iron is (a) +1 (b) +2 (c) +3 (d) +6

What is the chemical formula for marble? 

Marble is a metamorphic rock consisting of carbonate minerals that are recrystallized, the most common of which is calcite or dolomite. There are certain exceptions to the rule that marble is not foliated. Marble refers to metamorphosed limestone in geology, but its application in stonemasonry embraces metamorphosed limestone as well.

Marble is a popular sculptural material as well as a construction material. Metamorphism causes the original carbonate mineral grains to recrystallize in varying degrees. Marble rocks are often made up of an interlocking mosaic of carbonate crystals.

It is made up of several compounds. Marble is mainly made of calcite, dolomite, and maybe serpentine. Marble is composed of 38–42 percent lime (CaO), 20–25 percent silica (SiO2), 2–4 percent alumina (Al2O₃), and 1.5–2.5 percent oxides (NaO and MgO), and 30–32 percent water (MgCO₃ and others). Marble’s chemical formula is calcium carbonate(CaCO₃).

The qualities of marble or calcium carbonate are discussed further below.

The marble is either white or pink in tone. It is made of limestone and dolomite. It has a medium-sized grain and interlocking that can be seen with the naked eye. It is hard while being constructed of a soft mineral. It is either granoblastic or granular in structure. Since it consists of calcium carbonate, it may react with a wide range of acids.

Marble is used in the construction of monuments, buildings, sculptures, pavement, and other structures. Since ancient times, it has also been utilized as flooring. Although it is white, it may also be several hues. It is commonly found in metamorphic rocks such as gneiss and mica schists.