Chemistry Happy Birthday to Imani & Mark!

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. 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. 9.3

Naming Binary Molecular Compounds Naming Binary Molecular Compounds Naming Binary Molecular Compounds What does a prefix in the name of a binary molecular compound tell you about the compound’s composition? What does a prefix in the name of a binary molecular compound tell you about the compound’s composition? 9.3

Carbon and oxygen combine to form carbon monoxide (CO) and carbon dioxide (CO 2 ), but these two invisible gases are very different. Carbon and oxygen combine to form carbon monoxide (CO) and carbon dioxide (CO 2 ), but these two invisible gases are very different. 9.3 Naming Binary Molecular Compounds

Sitting in a room with small amounts of CO 2 in the air would not present any problems. If the same amount of CO were in the room, you could die of asphyxiation. A naming system that distinguishes between these two compounds is needed. Sitting in a room with small amounts of CO 2 in the air would not present any problems. If the same amount of CO were in the room, you could die of asphyxiation. A naming system that distinguishes between these two compounds is needed. 9.3 Naming Binary Molecular Compounds

A prefix in the name of a binary molecular compound tells how many atoms of an element are present in each molecule of the compound. A prefix in the name of a binary molecular compound tells how many atoms of an element are present in each molecule of the compound. 9.3 Naming Binary Molecular Compounds

Some guidelines for naming binary molecular compounds: Some guidelines for naming binary molecular compounds: Name the elements in the order listed in the formula. Name the elements in the order listed in the formula. Use prefixes to indicate the number of each kind of atom. Use prefixes to indicate the number of each kind of atom. 9.3 Naming Binary Molecular Compounds

Omit the prefix mono- when the formula contains only one atom of the first element in the name. Omit the prefix mono- when the formula contains only one atom of the first element in the name. The suffix of the name of the second element is -ide. The suffix of the name of the second element is -ide. 9.3 Naming Binary Molecular Compounds

Writing Formulas for Binary Molecular Compounds Writing Formulas for Binary Molecular Compounds Writing Formulas for Binary Molecular Compounds How do you write the formula for a binary molecular compound? How do you write the formula for a binary molecular compound? 9.3

Use the prefixes in the name to tell you the subscript of each element in the formula. Then write the correct symbols for the two elements with the appropriate subscripts. Use the prefixes in the name to tell you the subscript of each element in the formula. Then write the correct symbols for the two elements with the appropriate subscripts. 9.3 Writing Formulas for Binary 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. 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. 9.3 Writing Formulas for Binary Molecular Compounds

Assess students ’ understanding of the concepts in Section 9.3. Assess students ’ understanding of the concepts in Section Section Quiz.

1.Which of the following compounds is named INCORRECTLY? 1.Which of the following compounds is named INCORRECTLY? CS 2, carbon disulfide CS 2, carbon disulfide BCl 3, boron trichloride BCl 3, boron trichloride IF 7, iodine heptafluoride IF 7, iodine heptafluoride PCl 5, phosphorus hexachloride PCl 5, phosphorus hexachloride

2.Which of the following molecular compounds is named INCORRECTLY? 2.Which of the following molecular compounds is named INCORRECTLY? SbCl 3, antimony trichloride SbCl 3, antimony trichloride C 2 O 5, dicarbon pentoxide C 2 O 5, dicarbon pentoxide CF 4, carbon tetrafluoride CF 4, carbon tetrafluoride H 3 As, hydrogen arsenide H 3 As, hydrogen arsenide 9.3 Section Quiz.

3.The correct formula for tetraphosphorus trisulfide is 3.The correct formula for tetraphosphorus trisulfide is P 3 S 4 P 3 S 4 S 3 P 4 S 3 P 4 P 4 S 3 P 4 S 3 S 4 P 3 S 4 P Section Quiz.

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