"A formula that mirrors the kinds and also numbers of atoms in the the smallest representative unit of a substance"

While a formula unit is described as :

The lowest whole number proportion of ions in one ionic compound. Thus the formula unit for salt chloride is NaCl.

You are watching: Difference between molecule and formula unit

Though the definitions seem come differ, the composed formulas show up identical. A aufdercouch.net formula appears to it is in another method to stand for a formula unit. Because that example, NaCl is both the chemical formula and also formula unit for salt Chloride. Is there ever before a difference between the created terms?

ionic-compounds hatchet
improve this inquiry
edited jan 11 "17 at 14:39
asked jan 9 "17 at 19:13

17911 silver badge1111 bronze title
include a comment |

1 price 1

active earliest Votes
Molecular compound such together water exist as discrete particles, molecules. This is as result of the developing of covalent bonds whereby each atom has a particular partner come which the is bonded. Each molecule that water consists of one atom that oxygen and two atoms of hydrogen. So, H2O is the formula. This deserve to be more specifically referred to as a molecular formula.

In ionic link such together table salt, NaCl, the atom (as ions) carry out not shortcut to particular neighbors. Surrounding each chloride ion in a salt crystal are 6 sodium ions. Likewise, six chloride ions surround each sodium ion. This attraction the oppositely charged ion extends throughout the entire crystal. There is no discrete bonding of a details sodium ion to a particular chloride ion. For this reason the formula for salt chloride is expressed together the smallest totality number ratio between the Na and also Cl ion which is 1:1 for salt chloride. So, NaCl is additionally a formula yet not a molecule formula.

The factor for the term "formula unit" is the it is valuable when us talk about how lot of one substance is required to combine with a specific amount of one more substance. For example: to do the the smallest amount the hydrogen carbonate we incorporate one molecule of water through one molecule that carbon dioxide.

But now suppose we desire to incorporate silver nitrate through sodium chloride. Both of these are ionic compounds, they do not kind molecules. In this instance you would certainly say the one formula unit (FU) of sodium chloride combines with one FU of silver nitrate.

See more: What Is 800 Grams In Pounds, 800 Grams To Pounds Conversion

The one-to-one combine in both these examples is simply coincidence. It may take 3 FUs of problem A to integrate exactly v 2 FUs of substance B in a various example.