Unit 4 Chemical Formulas

Explain why sulfur aluminide is not the correct name for a compound formed between sulfur and aluminum.

Aluminum is the cation (positively charged ion), and it must be first. Sulfur is the anion (negatively charged ion), and it must be second. You should change the ending of sulfur to -ide, so the correct name would be aluminum sulfide.

Write the formula for this molecular compound: carbon tetrachloride

CCl4

Write the formula for this ionic compound: calcium carbonate

CaCO3

Write the formula for this molecular compound: dichlorine heptoxide

Cl2O7

Write the formula composed of this pair of ions: K+, Cl-

KCl

Write the formula composed of this pair of ions: Mg2+, N3-

Mg3N2

Write the formula for this ionic compound: magnesium sulfide

MgS

Write the formula for this ionic compound: manganese (II) nitrate

Mn(NO3)2

Write the formula for this molecular compound: dinitrogen pentabromide

N2Br5

Write the formula for this ionic compound: ammonium nitrite

NH4NO2

Write the formula composed of this pair of ions: Na+1, O2-

Na2O

Write the formula for this molecular compound: trisilicon tetranitride

Si3N4

Name this ionic compound: NH4NO3

ammonium nitrate

anion

any negatively charged ion (gains valence electrons to attain a noble gas configuration)

cation

any positively charged ion (loses valence electrons to attain a noble gas configuration)

ion

atom or group of atoms that have a positive or negative charge

Name this ionic compound: Ca(NO3)2

calcium nitrate

Name this molecular compound: CO2

carbon dioxide

Name this molecular compound: CCl4

carbon tetrachloride

How is a formula for ionic compounds written?

cation is always written first, followed by the anion

when naming ionic compounds, what do you do to the anion?

change the ending to -ide, unless it is a polyatomic ion

Name this ionic compound using roman numerals: CuOH

copper (I) hydroxide

polyatomic ion

ion made up of more than one atom; acts as an individual ion in a compound and its charge applies for the entire group of atoms

Name this ionic compound using roman numerals: FeI2

iron (II) iodide

Name this ionic compound using roman numerals: Pb(NO2)2

lead (II) nitrite

Name this molecular compound: N2O

nitrogen dioxide

ionic compounds have _______ net charge

no; positive and negative charges must equal 0

Name this molecular compound: PI3

phosphorus triiodide

Name this ionic compound: KClO3

potassium chlorate

superscripts

represent the charge of each element

subscripts

represent the number of ions of each element in an ionic compound

Name this ionic compound: Na3PO4

sodium phosphate

chemical bond

the force that holds two atoms together

roman numerals are used

to show the charge of a transition metal; put in parentheses between the two names

Name this ionic compound using roman numerals: ZnF2

zinc (II) fluoride