Chapter 2, Section

Home , Sodium nitride

Naming Simple Compounds Ionic Compounds

Ionic compounds

• consist of positive and negative ions.

• have attractions called ionic bonds between positively and negatively charged ions.

• have high melting and boiling points.

• are solid at room temperature.

Sodium chloride or “table salt” is an example of an ionic compound.

To name a compound that contains two elements,

• identify the cation and anion. • name the cation first followed by the name of the anion.

An ionic formula

• consists of positively and negatively charged ions.

• is neutral.

• has charge balance. total positive charge = total negative charge

The symbol of the metal is written first followed by the symbol of the nonmetal.

In MgCl2, • a Mg atom loses two valence electrons.

• two Cl atoms each gain one electron.

• subscripts indicate the number of ions needed to give charge balance.

In Na2S. • two Na atoms lose one valence electron each.

• one S atom gains two electrons.

Charge balance is used to write the formula for sodium nitride, a compound containing Na+ and N3−.

Na+ + 3− 3Na+N =Na3N Na+

3(+1) + 1(3-) = 0

Write the ionic formula of the compound with Ba2+ and Cl−.

• Write the symbols of the ions. Ba2+ Cl− • Balance the charges. Ba2+ Cl− two Cl- needed Cl− • Write the ionic formula using a subscript 2 for two chloride ions that give charge balance.

BaCl2

Select the correct formula for each of the following ionic compounds.

A. Na+ and S2-

1) NaS 2) Na2S3) NaS2

B. Al3+ and Cl-

1) AlCl3 2) AlCl 3) Al3Cl

C. Mg2+ and N3-

1) MgN 2) Mg2N3 3) Mg3N2

A. Na+ and S2-

2) Na2S check: 2Na+ + S2- = 2(1+) + 1(2-) = 0

B. Al3+ and Cl-

1) AlCl3 check: Al3+ + Cl- = (3+) + 3(1-) = 0

C. Mg2+ and N3-

3) Mg3N2 check: 2Mg2+ +2N3- = 2(3+) + 2(3-) = 0

Formula Ions Name cation anion NaCl Na+ Cl- sodium chloride + 2- K2SKS potassium sulfide MgO Mg2+ O2- magnesium oxide 2+ - CaI2 Ca I calcium iodide 3+ 2- Al2O3 Al O aluminum oxide

Write the formulas and names for compounds of the following ions: Br− S2− N3−

Na+

Al3+

Br− S2− N3−

NaBr Na2S Na3N sodium sodium sodium Na+ bromide sulfide nitride

AlBr3 Al2S3 AlN aluminum aluminum aluminum bromide sulfide nitride Al3+

Most transition metals and Group 4(14) metals form 2 or more positive ions.

Zn2+,Ag+, and Cd2+ form only one ion.

The name of metals with two or more positive ions (cations) use a Roman numeral to identify ionic charge.

Lead Pb2+ lead(II) Pb4+ lead(IV)

Transition metals with two different ions use a Roman numeral after the name of the metal to indicate ionic charge.

To name FeCl2 1. Determine the charge of the cation using the charge of the anion (Cl-). Fe ion + 2 Cl- = Fe ion + 2- = 0 Fe ion = 2+ 2. Name the cation by the element name and add a Roman numeral in parenthesis to show its charge. Fe2+ = iron(II) 3. Write the anion with an ide ending.

FeCl2 = iron(II) chloride

To name Cr2O3 1. Determine the charge of cation from the anion (O2-). 2 Cr ions + 3 O2- = 0 2 Cr ions + 3 (2-) = 0 2 Cr ions - 6 = 0 2 Cr ions = +6 Cr ion = 3+ = Cr3+ 2. Name the cation by the element name and add a Roman numeral in parenthesis to show its charge. Cr3+ = chromium(III) 3. Write the anion with an ide ending.

chromium(III) oxide = Cr2O3

Select the correct name for each.

A. Fe2S3 1) iron sulfide 2) iron(II) sulfide 3) iron(III) sulfide

B. CuO 1) copper oxide 2) copper(I) oxide 3) copper(II) oxide

Select the correct name for each.

A. Fe2S3 3) iron (III) sulfide Fe3+ S2-

B. CuO 3) copper (II) oxide Cu2+ O2-

A polyatomic ion • is a group of atoms. • has an overall ionic charge.

Some examples of polyatomic ions are + − NH4 ammonium OH hydroxide − − NO3 nitrate NO2 nitrite 2− 3− CO3 carbonate PO4 phosphate − HCO3 hydrogen carbonate (bicarbonate)

The names of common polyatomic anions • end in ate. − 3− NO3 nitrate PO4 phosphate • with one oxygen less end in ite. − 3− NO2 nitrite PO3 phosphite • with hydrogen attached use the prefix hydrogen (or bi). − HCO3 hydrogen carbonate (bicarbonate) − HSO3 hydrogen sulfite (bisulfite)

oxyanions

• The positive ion is named first followed by the name of the polyatomic ion.

NaNO3 sodium nitrate

K2SO4 potassium sulfate

Fe(HCO3)3 iron(III) bicarbonate or iron(III) hydrogen carbonate

(NH4)3PO3 ammonium phosphite

Match each formula with the correct name.

A. MgS 1) magnesium sulfite

MgSO3 2) magnesium sulfate

MgSO4 3) magnesium sulfide

B. Ca(ClO3)2 1) calcium chlorate

CaCl2 2) calcium chlorite

Ca(ClO2)2 3) calcium chloride

Match each formula with the correct name:

A. MgS 3) magnesium sulfide

MgSO3 1) magnesium sulfite

MgSO4 2) magnesium sulfate

B. Ca(ClO3)2 1) calcium chlorate

CaCl2 3) calcium chloride

Ca(ClO2)2 2) calcium chlorite

Name each of the following compounds:

A. Mg(NO3)2

B. Cu(ClO3)2

C. PbO2

D. Fe2(SO4)3

E. Ba3(PO3)2

Name each of the following compounds:

A. Mg(NO3)2 magnesium nitrate

B. Cu(ClO3)2 copper(II) chlorate

C. PbO2 lead(IV) oxide

D. Fe2(SO4)3 iron(III) sulfate

E. Ba3(PO3)2 barium phosphite

The formula of an ionic compound • containing a polyatomic ion must have a charge balance that equals zero (0). + − Na and NO3 Æ NaNO3

• with two or more polyatomic ions has the polyatomic ions in parentheses. 2+ − Mg and 2NO3 Æ Mg(NO3)2 subscript 2 for charge balance

Select the correct formula for each. A. aluminum nitrate

1) AlNO3 2) Al(NO)3 3) Al(NO3)3 B. copper(II) nitrate

1) CuNO3 2) Cu(NO3)2 3) Cu2(NO3) C. iron(III) hydroxide

1) FeOH 2) Fe3OH 3) Fe(OH)3 D. tin(IV) hydroxide

1) Sn(OH)4 2) Sn(OH)2 3) Sn4(OH)

Select the correct formula for each.

A. aluminum nitrate

3) Al(NO3)3 B. copper(II) nitrate

2) Cu(NO3)2 C. iron(III) hydroxide

3) Fe(OH)3 D. tin(IV) hydroxide

1) Sn(OH)4

Write the correct formula for each.

A. potassium bromate B. calcium carbonate C. sodium phosphate D. iron(III) oxide E. iron(II) nitrite

Write the correct formula for each.

A. potassium bromate KBrO3

B. calcium carbonate CaCO3

C. sodium phosphate Na3PO4

D. iron(III) oxide Fe2O3

E. iron(II) nitrite Fe(NO2)2

Hypochlorous acid is related to the anion found in common household bleach. Which of the following is that common anion?

– 1. ClO4 – 2. ClO3 – 3. ClO2 4. ClO–

Which of the following provides the correct name for

Ca(H2PO4)2?

1. Calcium dihydrogen phosphate 2. Calcium (II) hydrogen phosphate 3. Calcium di-dihydrogen phosphate 4. Calcium (II) dihydrogen phosphate

Covalent bonds form

• when atoms share electrons to complete octets.

• between two nonmetal atoms.

• between nonmetal atoms from Groups 4A(14), 5A(15), 6A(16), and 7A(17).

To name covalent Table 2.6 compounds • STEP 1: Name the first nonmetal as an element. • STEP 2: Name the second nonmetal with an ide ending. • STEP 3: Use prefixes to indicate the number of atoms (subscript) of each element.

What is the name of SO3?

1. The first nonmetal is S sulfur. 2. The second nonmetal is O named oxide. 3. The subscript 3 of O is shown as the prefix tri.

SO3 Æ sulfur trioxide

The subscript 1 (for S) or mono is understood.

Name P4S3.

1. The first nonmetal P is phosphorus. 2. The second nonmetal S is sulfide. 3. The subscript 4 of P is shown as tetra. The subscript 3 of S is shown as tri.

P4S3 Æ tetraphosphorus trisulfide

Select the correct name for each compound.

A. SiCl4 1) silicon chloride 2) tetrasilicon chloride 3) silicon tetrachloride

B. P2O5 1) phosphorus oxide 2) phosphorus pentoxide 3) diphosphorus pentoxide

C. Cl2O7 1) dichlorine heptoxide 2) dichlorine oxide 3) chlorine heptoxide

Select the correct name for each compound.

A. SiCl4 3) silicon tetrachloride

B. P2O5 3) diphosphorus pentoxide

C. Cl2O7 1) dichlorine heptoxide

Write the name of each covalent compound.

CO ______

CO2 ______

PCl3 ______

CCl4 ______

N2O ______

Write the name of each covalent compound.

CO carbon monoxide

CO2 carbon dioxide

PCl3 phosphorus trichloride

CCl4 carbon tetrachloride

N2O dinitrogen monoxide

The prefixes in the name are used to write the formula. STEP 1: Write the symbols in the order of the elements in the name. STEP 2: Write any prefixes as subscripts.

Example: Write the formula for carbon disulfide. STEP 1: Elements are C and S STEP 2: No prefix for carbon means 1 C Prefix di = 2

Formula: CS2

Write the correct formula for each of the following.

A. phosphorus pentachloride

B. dinitrogen trioxide

C. sulfur hexafluoride

Write the correct formula for each of the following.

A. phosphorus pentachloride

1 P penta = 5 Cl PCl5

B. dinitrogen trioxide

di = 2 N tri = 3 O N2O3

C. sulfur hexafluoride

1 S hexa = 6 F SF6

Identify each compound as ionic or covalent and give its correct name.

A. SO3

B. BaCl2

C. (NH4)3PO4

D. Cu2CO3

E. N2O4

Acids produce H+ when dissolved in water. They are compounds that ionize in water. If the anion does not contain oxygen:

HCl hydrogen chloride hydrochloric acid HF hydrogen fluoride hydrofluoric acid

If the anion contain oxygen

Anion ends in-ate, the suffix –ic is added to the root name. Anion ends in –ite, the suffix –ous.