Transcript chemistry
Naming and Writing Formulas for Molecular Compounds One milligram of gold is worth only about one cent, but one kilogram of gold is worth approximately $12,500. The correct prefix ( milli- or kilo-) makes quite a difference! Prefixes are important in chemistry, too. The prefixes in the name of a binary molecular compound tell you its composition. Naming and Writing Formulas for Molecular Compounds > Carbon and oxygen combine to form carbon monoxide (CO) and carbon dioxide (CO2), but these two invisible gases are very different. Slide 2 of 15 © Copyright Pearson Prentice Hall End Show Naming and Writing Formulas for Molecular Compounds > A prefix tells how many atoms of each element are present in one molecule. Prefix Number Prefix Number mono- 1 hexa- 6 di- 2 hepta- 7 tri- 3 octa- 8 tetra- 4 nona- 9 penta- 5 deca- 10 carbon monoxide (CO) carbon dioxide (CO2) © Copyright Pearson Prentice Hall Slide 3 of 15 End Show Naming and Writing Formulas for Molecular Compounds Molecular Naming> Rules: 1) Name the elements in the order listed in the formula. 2) Use prefixes to show the number of each atom. 3) The suffix of second element is -ide. 4) No prefix mono- for first element. CCl4 N 2O © Copyright Pearson Prentice Hall SO3 H 2O Slide 4 of 15 End Show Naming and Writing Formulas for Molecular Compounds > Silicon carbide is a hard material like diamond. The name silicon carbide has no prefixes, so the subscripts of silicon and carbon must be one. Thus, the formula for silicon carbide is SiC. Slide 5 of 15 © Copyright Pearson Prentice Hall End Show Quick Quiz! 1. Which of the following compounds is named INCORRECTLY? A. CS2, carbon disulfide B. BCl3, boron trichloride C. IF7, iodine heptafluoride D. PCl5, phosphorus hexachloride Slide 6 of 15 © Copyright Pearson Prentice Hall End Show Quick Quiz. 2. Which of the following molecular compounds is named INCORRECTLY? A. AsCl3, arsenic trichloride B. C2O5, dicarbon pentoxide C. CF4, carbon tetrafluoride D. H3As, hydrogen arsenide Slide 7 of 15 © Copyright Pearson Prentice Hall End Show Quick Quiz. 3. The correct formula for tetraphosphorus trisulfide is A. P3S4 B. S3P4 C. P4S3 D. S4P3 Slide 8 of 15 © Copyright Pearson Prentice Hall End Show