Naming Chemical Compounds
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Transcript of Naming Chemical Compounds
Naming Chemical Compounds
ReviewWhat is a chemical formula?
• shorthand representation of the composition of a substance using atomic symbols and numerical subscripts
ReviewWhat is a chemical formula?• shorthand representation of the composition of a substance using atomic symbols and numerical subscripts
• can represent a molecule (covalent bonded structure) or a formula unit (ionic bonded structure)
ReviewSignificance of a chemical
formula
• formula tells number and type of atoms in a molecule or formula unit (one atom difference can cause change in properties)
ReviewSignificance of a chemical
formula• formula tells number and type of atoms in a molecule or formula unit (one atom difference can
cause change in properties)
• Examples: Ag, NaCl, HCl, Al2(SO4)3, CaSO4 5 H2O, etc.
Naming Ionic Compounds
Binary ionic compounds• Metal named first• Name of non-metal has –ide added• If metal has more than one possible
charge use stock system (Roman numerals) or common name
Naming Ionic Compounds
Binary ionic compounds• Metal named first
• Name of non-metal has –ide added
• If metal has more than one possible charge use stock system (Roman numerals) or common name
Ex: NaCl, KI, FeF2, FeF3
Naming Ionic Compounds
Compounds with polyatomic ions
• Cation is named first (using stock or common name)
• Anion is named second (using name of polyatomic ion)
Naming Ionic Compounds
Compounds with polyatomic ions• Cation is named first (using stock or common name)• Anion is named second (using name of polyatomic ion)
Al2(CO3)3, BaSO4, CaSO3, Fe(NO3)2, NH4Cl
(DO NOT change endings of polyatomic ions!!!)
Naming Ionic Compounds
Hydrates• ionic compounds that absorb
water into their structures
• named like regular ionic compounds, add numeric prefix and hydrate at the end
Naming Ionic Compounds
Prefixes:
1: mono-
2: di-
3: tri-
4: tetra-
5: penta-
6: hexa-
7: hepta-
8: octa-
9: nona-
10: deca-
Naming Ionic Compounds
Hydrates• ionic compounds that absorb water into their structures• named like regular ionic compounds, add numeric prefix and hydrate at the end
MgSO4 7 H2O, CuSO4 5 H2O
Naming Ionic Compounds
Want more help? Try watching the video at https://youtu.be/TQKIbJIqLeA.
Naming Molecular Compounds
Binary molecular compounds• Element from left-most part of
table is named first• Name of second element has –ide
added• Use Greek prefixes to indicate
number of atoms
Naming Molecular Compounds
Prefixes:1: *mono-(*only with second element)2: di-3: tri-4: tetra-5: penta-
6: hexa-7: hepta-8: octa-9: nona-10: deca-
Naming Molecular Compounds
Binary molecular compounds• Element from left-most part of table is named first
• Name of second element has –ide added
• Use Greek prefixes to indicate number of atoms
CO, CCl4, N2O, N2O3
Naming Molecular Compounds
Acids
• when in water, produce H+ ions, name usually from characteristic anion
• Hydro acids: hydro + name of halogen + -ic + acid
Naming Molecular Compounds
Acids• when in water, produce H+ ions, name usually from characteristic anion
• Hydro acids: hydro + name of halogen + -ic + acid
HCl, HF, HBr
Naming Molecular Compounds
Acids• when in water, produce H+ ions, name usually from characteristic anion
• Hydro acids: hydro + name of halogen + -ic + acid
HCl, HF, HBr
• Oxoacids: polyatomic ion + acid (use –ous and –ic as needed, -ic goes with > # O atoms)
Naming Molecular Compounds
Acids• when in water, produce H+ ions, name usually from characteristic anion
• Hydro acids: hydro + name of halogen + -ic + acid
HCl, HF, HBr
• Oxoacids: polyatomic ion + acid (use –ous and –ic as needed, -ic goes with > # O atoms)
H2SO4, HNO2, HNO3
Naming Molecular Compounds
Want more help? Try watching the video at https://youtu.be/VokWJy_jpAc.
Naming Chemical Compounds
Given: Chemical Formula
Wanted: Name of Compound
• Need to ask questions to determine which naming rules to use
• Here is one set of questions you could use…
Has a metal?
No
NoNo
NoNo
Yes
YesYes
Yes
Yes
Has hydrogen in the formula? Has only two elements?
binary molecularcompound
Has oxygen?
hydroacid oxoacid
binary ioniccompound
Has H2O in theformula?
polyatomic ioniccompound
hydrate
Writing Formulas
• Use the criss-cross method – the charges (superscripts) go to the bottom (as subscripts) and switch from right to left
Writing Formulas
Examples:• Fe3+ + Cl1- becomes
• Al3+ + O2- becomes
• Sn2+ + O2- becomes
• Mg2+ + (OH)1- becomes
• NH41+ + SO4
2- becomes
• FeCl3
• Al2O3
• SnO
• Mg(OH)2
• (NH4)2SO4
Writing Formulas
• Remember: you are looking for the smallest whole-number ratio of ions that will give an overall charge of 0 – that’s why the 3rd example has no subscripts (2+ +2- = 0)