Drill

Determine the formulas for the following:

1. Na and Cl2. Zn 2+ and Cl

Objective

The student will be able to: Generate rules in order to practice naming

and writing formulas for binary molecular compounds.

SAT/HSA Enrichment

When gypsy moth caterpillars hatch, which of these populations benefits first?

a. red oakb. deer tickc. blue jayd. carpenter ant

Ionic Compounds Review

Working in groups and using the white boards we are going to complete the review worksheet. Points gained will be used towards your quiz

grade.

Quiz

Naming Ionic Compounds Name or write the formula for the ionic

compounds.

Engagement:

Numerical Prefixes: Match the correct prefixes with the correct

number.

Naming and Writing Formulas for Molecular Compounds

What is the relationship between the name and the formula of a compound?

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.

Carbon and oxygen combine to form carbon monoxide (CO) and carbon dioxide (CO2), but these two invisible gases are very different.

Naming Binary Molecular Compounds

Sitting in a room with small amounts of CO2 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.

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.

Naming Binary Molecular Compounds

Some guidelines for naming binary molecular compounds: Name the elements in the order

listed in the formula. Use prefixes to indicate the number

of each kind of atom.

Naming Binary Molecular Compounds

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.

Naming Binary Molecular Compounds

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.

Writing Formulas for BinaryMolecular 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.

Writing Formulas for BinaryMolecular Compounds

Section 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

2. Which of the following molecular compounds is named INCORRECTLY?

a. SbCl3, antimony trichloride

b. C2O5, dicarbon pentoxide

c. CF4, carbon tetrafluoride

d. H3As, hydrogen arsenide

Section Quiz

3.The correct formula for tetraphosphorus trisulfide is

a. P3S4

b. S3P4

c. P4S3

d. S4P3

Section Quiz

Naming Binary Molecular Compounds

Students divide into eight groups. Each group is responsible for generating

three rules for naming binary molecular compounds

Post your rules on chart paper and post on the board, under Rule 1, Rule 2, and Rule 3.

Class Discussions

Students discuss the rules they generated and come up with a final rule that incorporates the student’s ideas.

Using the generated rules the class will complete Part II of the Naming Binary Molecular Compounds worksheet.

Writing and Naming Molecular Compounds

Students will work in pairs to complete worksheet.

Class will review answers to the worksheet.

Summary

1. Did we accomplish the objective? Explain.

2. Explain a system that may be used when naming binary molecular compounds.

3. When is it appropriate to add a prefix to the first element of a binary molecular compound?

Summary

1. When is it not appropriate to add a prefix to the second element of a binary molecular compound?

2. What is the suffix that should be added to the end of the second element? The first element?

3. Name the following binary molecular compounds:

PBr3 P2O3

Homework

9.3 Naming and Writing Formulas for Molecular Compounds worksheet.

Exit ticket Naming and Writing Formulas for Molecular

Compounds