Hint: Count the number of atoms of each element, and then multiply that number by the element's atomic weight. Use the table below to find the atomic weight of each atom (element), or refer to a Periodic Table of the Elements. Let us calculate the molecular weight of some common compounds. For example, in one mole of a chemical compound there are 6.022 x 1023 molecules. One mole of 'something' contains 6.022 x 1023 entities. A mole is the unit that measures the amount of a substance. One thousand mers connected together would add up to a weight of 28,000 grams/mole and would have 6,000 atoms.Ī mole is the standard method in chemistry for communicating how much of a substance is present. We combine (react) many mers of ethylene together to form a polyethylene chain. The atomic weight of carbon is 12 and that of hydrogen is 1, so one mer of ethylene has a weight of 2(12) + 4(1) = 28. It has a total of 6 atoms: 2 carbon (C) atoms and 4 hydrogen (H) atoms. The chemical formula for an ethylene monomer is -(CH2-CH2).In order to calculate the molecular weight of one water molecule, we add the contributions from each atom that is, 2(1) + 1(16) = 18 grams/mole. The original periodic table of the elements published by Dimitri Mendeleev in 1869 arranged the elements that were known at the time in order of increasing atomic weight, since this was prior to. Using the periodic table of the elements to find atomic weights, we find that hydrogen has an atomic weight of 1, and oxygen's is 16. One molecule of water (H 2 O) would weigh 18.02 amu (2×1.00797 amu for H + 15.9994 amu for O), and a mole of water molecules would weigh 18.02 grams. The chemical formula for water is H2O, which means this molecule has 3 atoms: 2 of hydrogen (H) and 1 oxygen (O) atom.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |