What is the difference between a formula unit and a molecular formula?

Answer 1

Molecular formulas refer to covalently bonded substances (molecules). The molecular formula shows the exact number of atoms of each element present in the smallest unit of the substance. For example, benzene is a molecule composed of six carbon and six hydrogen atoms and has a formula C6H6.

A formula unit refers to ionic compounds and network solids (both are crystals). Because in ionic crystals each ion is electrostatically bonded to every oppositely charged nearest neighbor, the ions in the whole crystal can be thought of as part of one single bonded entity. It is the same with network solids except that the bond is covalent. So rather than using a formula that shows all of the elements present in any one particular crystal, the formula unit shows the elements present in the smallest whole number ratio. In a common example, sodium chloride, the formula unit is NaCl since sodium and chloride are present in the crystal in a 1:1 ratio. The NaCl crystal itself, however, would have >>quintillians each of Na and Cl if it was big enough to see with the unaided eye. It is important to not confuse formula units with emprical formulas. Emprical formulas are simply the lowest whole number ratio of elements in a compound. Formula units are always empirical, whereas molecular formulas are usually not. For example, the empirical formula of benzene, C6H6, is CH, since there is a 1 to 1 ratio of C to H. Note that several molecules can have the same empirical formula. For example acetylene, with molecular formula C2H2, also has the same empirical formula as benzene, even though the two molecules are very different! Water, H2O, is an example of a molecular formula that is also empirical.

A formula unit is the symbolic representation of an ionic compound or network solid, and a molecular formula is the symbolic representation of a molecular compound.

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Answer 2

An atom is the smallest particle of an elementthat still has the properties of the element. A molecule is the smallest particle of a substance made of combined atomsthat has the properties of that substance.

Answer 3

A molecule unit is the simplest structure of an atom or compound.

A formula unit is the symbol that happens to represent an ionic compound or network solid. Examples: ionic-NaCl and K2O and covalent networks-SiO2 and C ( diamond or graphite)

Answer 4

An Atom is the smallest particle of an element with the element's properties.

A Molecule is a combination of atoms, like H20.

Formula Units are like Molecules but for Ions. Because of this, a nonmetals + metals = Ionic compounds, and are therefore measured with f.u.

Ions are negatively of positively charged particles.

Answer 5

A formula unit is like a molecule in that they are both composed of atoms; however, a formula unit is unlike a molecule in that it exists only as part of a larger structure (e.g. table salt). The atoms of a molecule bond to make specific individuals.

In a formula unit of table salt, no sodium ion pairs with a specific chlorine ion (see link below to an image of the 3D structure of salt); however, in water, a single hydrogen atom pairs with two specific oxygen atoms.

Answer 6

formula unit mass gives the ratio of constituents in ionic compound.It does not represent a molecule.For example when we consider NaCl ,we can see there is no molecules present in it but instead contains sodium and chloride ions.

Answer 7

- The molecule is a group of elements chemically bounded.
- An ion is an atom or group of atoms having an electrical charge.
- Formula unit is the simplest entity in a compound having a lattice structure.

Answer 8

A molecule name is the actual scientific name that is used to adress that molecule, a chemical formula is formula that can be used to make that specific molecules.