Homework Solutions

2:17    b

2:18.    If barium forms a compound with nitrate (an anion known to have a '-1' charge) the compound will be an ionic compound and barium will have a '+2' charge.  Ba⁺² is the only stable barium cation.  If iron forms a compound with nitrate, the compound will be ionic, but the name 'iron nitrate' does not tell us what the compound is because iron has more than one stable cationic form.  Iron can have '+3' or '+2' charge.  We use the roman numeral (II) to tell use that--in this ionic compound--iron has a '+2' charge. 

2:19    The prefix 'di' suggests covalent bonds.  Calcium chloride is an ionic compound.  We know calcium has a '+2' charge in this compound because it is a group II metal and '+2' is the only stable positive charge it can have.

2:38                                                                                            2:40

a.    sodium perchlorate                                                                    a.    hydrogen acetate (acetic acid when (aq))
b.    magnesium phosphate                                                                b.    ammonium nitrite 
c.    aluminum sulfate                                                                         c.    cobalt (III) sulfide 
d.  sulfur difluoride                                                                            d.    Iodine chloride 
e.    sulfur hexafluoride                                                                      e.    lead (II) phosphate 
f.    sodium hydrogen phosphate                                                        f.    potassium iodate 
g.    sodium dihydrogen phosphate                                                     g.    hydrogen sulfate (sulfuric acid when (aq)) 
h.    lithium nitride                                                                              h.    strontium nitride 
i.    sodium hydroxide                                                                        i.    aluminum sulfite 
j.    magnesium hydroxide                                                                  j.    tin (IV) oxide 
k.    aluminum hydroxide                                                                    k.    sodium chromate 
l.    silver chromate                                                                             l.    hydrogen hypochlorite (hypochlorous acid when (aq)) 

2:42

a.    Na₂O                                                                                        h.    CuCl
b.    Na₂O₂                                                                                      i.    GaAr 
c.    KCN                                                                                         j.    CdSe 
d.    Cu(NO₃)₂                                                                                 k.    ZnS          
e.    SiCl₄                                                                                          l.    Hg₂Cl₂     
f.    PbO                                                                                            m.    HNO₂(aq)           
g.    PbO₂                                                                                          n.    P₂O₅