H 1 Hydrogen 1.00794 | Periodic Table | He 2 Helium 4.002602 | |||||||||||||||

Li 3 Lithium 6.941 | Be 4 Beryllium 9.012182 | of the Elements | B 5 Boron 10.811 | C 6 Carbon 12.0107 | N 7 Nitrogen 14.0067 | O 8 Oxygen 15.9994 | F 9 Fluorine 18.9984032 | Ne 10 Neon 20.1797 | |||||||||

Na 11 Sodium 22.98976... | Mg 12 Magnesium 24.305 | mouse/touch for more information | Al 13 Aluminum 26.9815386 | Si 14 Silicon 28.0855 | P 15 Phosphorus 30.973762 | S 16 Sulfur 32.065 | Cl 17 Chlorine 35.453 | Ar 18 Argon 39.948 | |||||||||

K 19 Potassium 39.948 | Ca 20 Calcium 40.078 | Sc 21 Scandium 44.955912 | Ti 22 Titanium 47.867 | V 23 Vanadium 50.9415 | Cr 24 Chromium 51.9961 | Mn 25 Manganese 54.938045 | Fe 26 Iron 55.845 | Co 27 Cobalt 58.933195 | Ni 28 Nickel 58.6934 | Cu 29 Copper 63.546 | Zn 30 Zinc 65.38 | Ga 31 Gallium 69.723 | Ge 32 Germanium 72.63 | As 33 Arsenic 74.9216 | Se 34 Selenium 78.96 | Br 35 Bromine 79.904 | Kr 36 Krypton 83.798 |

Rb 37 Rubidium 85.4678 | Sr 38 Strontium 87.62 | Y 39 Yttrium 88.90585 | Zr 40 Zirconium 91.224 | Nb 41 Niobium 92.90628 | Mo 42 Molybdenum 95.96 | Tc 43 Technetium (98) | Ru 44 Ruthenium 101.07 | Rh 45 Rhodium 102.9055 | Pd 46 Palladium 106.42 | Ag 47 Silver 107.8682 | Cd 48 Cadmium 112.411 | In 49 Indium 114.818 | Sn 50 Tin 118.71 | Sb 51 Antimony 121.76 | Te 52 Tellurium 127.6 | I 53 Iodine 126.90447 | Xe 54 Xenon 131.293 |

Cs 55 Caesium 132.9054 | Ba 56 Barium 132.9054 | Hf 72 Hafnium 178.49 | Ta 73 Tantalum 180.94788 | W 74 Tungsten 183.84 | Re 75 Rhenium 186.207 | Os 76 Osmium 190.23 | Ir 77 Iridium 192.217 | Pt 78 Platinum 195.084 | Au 79 Gold 196.966569 | Hg 80 Mercury 200.59 | Ti 81 Thallium 204.3833 | Pb 82 Lead 207.2 | Bi 83 Bismuth 208.9804 | Po 84 Polonium (209) | At 85 Astatine (210) | Rn 86 Radon (222) | |

Fr 87 Francium (223) | Ra 88 Radium (226) | Rf 104 Rutherfordium (267) | Db 105 Dubnium (268) | Sg 106 Seaborgium (271) | Bh 107 Bohrium (272) | Hs 108 Hassium (270) | Mt 109 Meitnerium (276) | Ds 110 Darmstadium (281) | Rg 111 Roentgenium (280) | Cn 112 Copernicium (285) | Uut 113 Unutrium (284) | Uuq 114 Flerovium (289) | UuP 115 Ununpentium (288) | Lv 116 Livermorium (293) | Uus 117 Ununseptium (294) | Uuo 118 Ununoctium (294) | |

La 57 Lanthanum 138.90547 | Ce 58 Cerium 140.116 | Pr 59 Praseodymium 140.90765 | Nd 60 Neodymium 144.242 | Pm 61 Promethium (145) | Sm 62 Samarium 150.36 | Eu 63 Europium 151.964 | Gd 64 Gadolinium 157.25 | Tb 65 Terbium 158.92535 | Dy 66 Dysprosium 162.5 | Ho 67 Holmium 164.93032 | Er 68 Erbium 167.259 | Tm 69 Thulium 168.93421 | Yb 70 Ytterbium 173.054 | Lu 71 Lutetium 174.9668 | |||

Ac 89 Actinium (227) | Th 90 Thorium 232.03806 | Pa 91 Protactinium 231.0588 | U 92 Uranium 238.02891 | Np 93 Neptunium (237) | Pu 94 Plutonium (244) | Am 95 Americium (243) | Cm 96 Curium (247) | Bk 97 Berkelium (247) | Cf 98 Californium (251) | Es 99 Einstenium (252) | Fm 100 Fermium (257) | Md 101 Mendelevium (258) | No 102 Nobelium (259) | Lr 103 Lawrencium (262) |

Chemists regularly use both moles and liters as units to describe the quantity of chemical substances. However, there is a fundamental difference between the two. Moles describe a standard quantity of atoms or molecules of a substance. The number of particles in a mole is sometimes referred to as Avogadro's number and is very large, typically represented as: 6.02 x 10^23. Liters, however, are a measure of volume used in the metric system. You can convert from liters to moles if you know the density of your chemical and if you first calculate its molecular weight.

Write out the chemical formula of the chemical you are converting from liters to moles. This formula shows how many types of atoms are in each molecule as well as how many of each type. The chemical cyclohexane, for example, has the formula C6H12.

Look up the atomic weight of each element in the chemical formula, using a periodic table. For cyclohexane, you would look up the atomic weight of carbon (C), which is 12.01 and hydrogen (H), which is 1.008.

## Sciencing Video Vault

Multiply the atomic weight of each element by the number of atoms of that element in the formula, then add all the resulting products. This value is the gram molecular weight of the chemical, in units of grams per mole. In the case of cyclohexane, you would calculate (12.01)(6) + (1.008)(12) = 84.16 grams per mole.

Multiply the volume of the compound, in liters, by 1,000. This will convert the volume into units of milliliters. If you had 2 liters of cyclohexane, for example, you would convert this as follows; 2 x 1000 = 2,000 milliliters.

Multiply the volume of your chemical, in milliliters, by the density value, in grams per milliliter. This calculation gives you the weight of the compound, in grams. Labs and technical reference sources commonly use units of grams per milliliter to describe the density of substances. You can find the density of your compound in the "physical properties" section of the Material Safety Data Sheet which the manufacturer provides with the chemical. The density of cyclohexane is 0.78 grams per milliliter, so the weight of cyclohexane in 2,000 milliliters is (2000)(0.78) = 1,560 grams.

Divide the weight you just calculated by the gram molecular weight of your chemical, in grams per mole. The result is the number of moles of the compound in the number of liters you started with at the beginning of your calculations. In the case of the example, the moles of cyclohexane are found by the calculation 1,560 grams/84.16 grams/mole = 18.5 moles.

#### Tip

Make sure that the value of density you use in your calculations is for appropriate temperature, since the density of a compound can change substantially with temperature.