What is Chemical formula: Definition and 31 Discussions

A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus (+) and minus (−) signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae.
The simplest types of chemical formulae are called empirical formulas, which use letters and numbers indicating the numerical proportions of atoms of each type. Molecular formulae indicate the simple numbers of each type of atom in a molecule, with no information on structure. For example, the empirical formula for glucose is CH2O (twice as many hydrogen atoms as carbon and oxygen), while its molecular formula is C6H12O6 (12 hydrogen atoms, six carbon and oxygen atoms).
Sometimes a chemical formula is complicated by being written as a condensed formula (or condensed molecular formula, occasionally called a "semi-structural formula"), which conveys additional information about the particular ways in which the atoms are chemically bonded together, either in covalent bonds, ionic bonds, or various combinations of these types. This is possible if the relevant bonding is easy to show in one dimension. An example is the condensed molecular/chemical formula for ethanol, which is CH3-CH2-OH or CH3CH2OH. However, even a condensed chemical formula is necessarily limited in its ability to show complex bonding relationships between atoms, especially atoms that have bonds to four or more different substituents.
Since a chemical formula must be expressed as a single line of chemical element symbols, it often cannot be as informative as a true structural formula, which is a graphical representation of the spatial relationship between atoms in chemical compounds (see for example the figure for butane structural and chemical formulae, at right). For reasons of structural complexity, a single condensed chemical formula (or semi-structural formula) may correspond to different molecules, known as isomers. For example glucose shares its molecular formula C6H12O6 with a number of other sugars, including fructose, galactose and mannose. Linear equivalent chemical names exist that can and do specify uniquely any complex structural formula (see chemical nomenclature), but such names must use many terms (words), rather than the simple element symbols, numbers, and simple typographical symbols that define a chemical formula.
Chemical formulae may be used in chemical equations to describe chemical reactions and other chemical transformations, such as the dissolving of ionic compounds into solution. While, as noted, chemical formulae do not have the full power of structural formulae to show chemical relationships between atoms, they are sufficient to keep track of numbers of atoms and numbers of electrical charges in chemical reactions, thus balancing chemical equations so that these equations can be used in chemical problems involving conservation of atoms, and conservation of electric charge.

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  1. D

    What is the charge for Hexaminotriphenylene?

    I have seen the structures like X3 (HITP)2 (X = Cr, Mn, Fe, Co, Rh, Os, Ir). Can I replace X with Mg? Will it be stable?
  2. M

    Understanding Polyatomic Ion Charges and Number of Oxygen

    I have recently started self studying chemistry and I am at the point where I'm learning to name chemicals given chemical formulas and vice versa. (Like Iron (III) Oxide --> Fe2O3). I am having trouble with doing this process for polyatomic ionic compounds. I can't seem to remember some the...
  3. nineteen

    Chemistry Finding the Chemical Formula and Relative Molecular Mass

    My chemistry teacher gave me this problem. I tried and tried, but I couldn't figure it out and the deadline is tomorrow. Please help me out here friends. 1. This is the problem : In a compound which is made of element Y, weight percentage of Y is 72% and N( Nitrogen) is 28%. Also, 3 Y atoms...
  4. davenn

    Difference - chemical formula and Idealised chemical formula

    Hi guys I'm into rocks and minerals but I'm not a chemist I can't really find a definition between ... chemical formula and Idealised chemical formula ? example below of a mineral sample I purchased a few days ago part info from ... https://www.mindat.org/min-3760.html Chemical Properties of...
  5. J

    What's the difference of this chemical formula?

    Homework Statement I found out that Bauxite has 2 formula, which one is 2Al(OH)3, and the other one is Al2Si2O5(OH)4⋅2H2O. What's the difference of these formula? Homework EquationsThe Attempt at a Solution
  6. T

    A Predicting Fermi Surface from Chemical Formula

    Hi, I was hoping I could get some things cleared up. Recently my Solid State professor mentioned that we could simply, from the chemical formula, predict where the band crossings are going to be. For example, take LaFeAsO. Since La has a valency of +3, Fe of +3, As of -3, and O of -2, he...
  7. iTryToLearn

    Give the chemical formulas for four possible salts

    Lets say you were given an unknown which contains two salts, and your results give you evidence that potassium phosphate, ammonium, and carbonate ions are all present. What are four possible salts that could be your unknown?
  8. gracy

    What Is the Chemical Formula of Bornite?

    What's the chemical formula of bornite?According to wikipedia http://en.wikipedia.org/wiki/Bornite it is Cu5FeS4.According to http://www.spiritofisis.org/knowledge/crystal_files/bornite.htm it is Cu2FeS4 and as per my textbook it is Cu3FeS2.Now,What's the actual chemical formula of bornite?I...
  9. I

    What's the chemical formula of cement and resin?

    Hi, i need to know the chemical formula of cement and resin and their densities. can someone help me, please? thank you in advance !
  10. S

    Help required with chemical formula and spectrophotometry

    Hi guys, I have what I hope is a simple question. basically I have a known crystal structure with a known dopant, however I don't know what the charge on the dopant is and I can't find it in any papers. Now I'm not sure if this is something I just need to find or whether this is something I can...
  11. Y

    What is the chemical formula for car exhaust emission

    What is the chemical formula for car exhaust emission
  12. J

    Determing The Chemical Formula of a Hydrate

    Homework Statement When copper (II) sulfate hydrate, a blue crystalline solid containing embedded water molecules (called a hydrate), is heated in air, it loses the water molecules and the blue solid is transformed to a white anyhydrous (no water) crystal known as copper (II) sulfate.Homework...
  13. MacLaddy

    Are My Chemical Reaction Equations Correct?

    Homework Statement I have a couple of problems here that are all part of one homework problem. A,B,C, and D. I have completed what I believe are the correct answers, but I really don't know for sure. This is an online chemistry class, and it really is not very good. I've watched about 3...
  14. W

    What is the Chemical Formula of Diesel?

    Homework Statement For a assessment task at school, I have to compare various types of fuel, one of which is diesel. One aspect of the task is to name the chemical formula for each fuel. The Attempt at a Solution I keep finding that the formula for diesel is C12H23. I know that diesel is...
  15. O

    What is the chemical formula of cement?

    Homework Statement If limestone (calcium carbonate) and clay (assume aluminum silicate) are mixed together and heated then the result is cement. Cement is a mixture of calcium oxide, carbon dioxide, aluminum oxide, and calcium silicate. These bags can be purchased at any building supplies...
  16. H

    Balancing equation - What is the chemical formula of cement?

    There are 2 parts to this question: 1. If limestone (calcium carbonate) and clay (assume aluminum silicate) are mixed together and heated then the result is cement. Cement is a mixture of calcium oxide, carbon dioxide, aluminum oxide, and calcium silicate. These bags can be purchased at any...
  17. T

    What am i doing wrong with this chemical formula?

    I think this chemical balance is correct but I'm not sure if I am writing it right or not. Any help?
  18. J

    What is the chemical formula of pure milk?

    What is the chemical formula of pure milk? What is the chemical reaction taking place when milk combines with salt? thanks in advance.:smile:
  19. J

    Chemical Formula of Amino Acid

    what is the chemical formula of amino acid?
  20. B

    Fuel may be designated by the chemical formula C51 H105 S2 (OH)3

    Homework Statement A fuel may be deignated by the chemical formula C51 H105 S2 (OH)3 Write out the balance equation for complete combustion of this fuel. Homework Equations Cx Hy Oz Sn [(x) + (y/4)] o2 > xCo2 + (y/2) H2o The Attempt at a Solution The problem is that I...
  21. S

    What is Diesel Fuel's Chemical Formula?

    hello, my name is Jesse and I'm new to the forums. I'm in 10th grade chemistry and i have a question. what is the chemical formula of diesel fuel? i searched it on google and found something about hydrocarbon and i have no idea what this is. please help
  22. M

    Does Mixing 2-Propanone and 2-Ethylhexanol Create C11 H24 O2?

    If I add the chemicals C3 H6 O (2-propanone) and C8 H18 O (2-ethylhexanol) will I wind up with the chemical formula C11 H24 O2 ? thanks
  23. K

    Vetro paste chemical formula

    i m a student of Chemistry , and i got a university assignment and i need ur kind help in this matter , i need information about a chemical its name is [Vetro Paste 0.23A what is this , its chemical formula , structure , its physical and chemical properties , and its uses , please guide...
  24. S

    Chemical Formula Hydrate Lab

    We did a lab at our school recently but some of the questions regarding the lab confused me. The data obtained from the lab is here: Determining the Chemical Formula of a Hydrate Purpose Find the molecular formula of the hydrate of Copper (II) Sulfate, CuSO4 x H20. Prediction When the...
  25. M

    What is this chemical formula of?

    Can someone tell me what this chemical structure is? [PLAIN][/URL]
  26. C

    Does anyone know the chemical formula of cheese?

    I'm interested in trying to find this out because I'm wondering if i could artificially make it from school materials...also i want to do a presentation on it tommorow, if i can't find the relevant information I'm going to have to do my presentation on ionisation energy, which is easy, and which...
  27. F

    Silicon & Neon Compound: Formula & Explanation

    If aluminum has a positive 3 charge and chlorine has a negative 1 charge, then the formula becomes AlCl3, because the negative three in chlorine would balance out the positive 3 in aluminum right? So, what about this? Silion has a positive 4 charge. and neon has a neutral charge. What would the...
  28. H

    Oleic Acid: Chemical Formula and Uses

    What is the chemical formula for oleic acid?
  29. L

    Chemical formula and thoretical/percent yield.

    2 ml of 15M Nitric acid was added to copper bromide(CuBr) and gently heated until a black substance was formed, copper oxide(CuO), and was completely dry. There was .93g of CuO formed in the reaction. The CuO was formed from the decomposition of the copper nitrate produced by the reaction of...
  30. MC363A

    Question about chemical formula

    Can anyone tell me what the chemical formula for Chlorothyl is. I would appreciate any help, and I will give full credit to the person who answers in my bibliography. Thank you!
  31. Nim

    What Does the Dots and Numbers Mean in this Chemical Formula?

    I don't get this: "Its empirical formula is C 10 H 17 N 3 S • 2 HCl • H 2 O" What is with those dots? And the middle part has a number before a letter...