- WELCOME TO A CHEMISTRY VIDEO TUTORIAL
THAT WILL COVER BINARY COVALENT COMPOUNDS
AND DIATOMIC MOLECULES AND THEIR NOMENCLATURE.
LET'S GET STARTED. ALL RIGHTY.
NOW, WHAT EXACTLY IS A DIATOMIC MOLECULE?
WELL, IT'S A COMPOUND CONTAINING TWO IDENTICAL ELEMENTS, RIGHT?
SO REMEMBERING ELEMENTS ARE UNIQUE.
WE CAN HAVE MORE OF--
YOU CAN JUST STOP THERE, ALL RIGHT?
SO THAT'S ALL IT IS.
NOW, THERE'S A VERY SIMPLE PHRASE
THAT CAN HELP US KNOW AND MEMORIZE THE DIATOMIC MOLECULES,
"HAVE NO FEAR OF ICE COLD BEER," ALL RIGHT?
SO HOW DOES THAT HELP US, RIGHT?
WELL, IF WE LOOK AT THE FIRST LETTER OF OUR PHRASE,
IT WILL LET US KNOW WHICH ELEMENTS EXIST
AS DIATOMIC MOLECULES,
HYDROGEN, NITROGEN, FLUORINE, OXYGEN,
IODINE, CHLORINE, AND BROMINE.
SO WHENEVER YOU READ THESE ELEMENT NAMES,
YOU NEED TO VISUALIZE THE DIATOMIC MOLECULAR FORMULA.
FOR EXAMPLE, WHEN WE SAY WE BREATHE OXYGEN,
IT'S DIATOMIC OXYGEN, ALL RIGHT?
NOW WE'VE ALREADY LEARNED SOME ION NAMES,
SO WE NEED TO KEEP EVERYTHING STRAIGHT, RIGHT?
SO IF WE REFER TO HYDROGEN, WE'RE REFERRING TO H (II).
ANOTHER IMPORTANT EXAMPLE HERE WOULD BE A HYDROGEN ION, RIGHT?
SO IF WE'RE TALKING ABOUT A HYDROGEN ION,
THEN OF COURSE THAT WOULD BE H+,
OR HYDRIDE IS WITH THE H-, RIGHT?
NITROGEN, THE DIATOMIC MOLECULE VERSUS NITRIDE, RIGHT?
SO IT'S ALL IN THE SUFFIXES.
SO IF WE LOOK AT THE SUFFIXES HERE,
THEY ARE FOR THE ELEMENT NAMES.
AND SO IN A SCIENTIFIC CONTEXT,
WHENEVER WE USE THESE ELEMENT NAMES
WE NOW KNOW THEY EXIST AS THESE DIATOMIC MOLECULES.
IF WE WANTED TO TALK ABOUT A HYDROGEN ATOM ALL BY ITSELF,
THAT WOULD BE ATOMIC HYDROGEN.
ALL RIGHT.
AND THEN OF COURSE ON THE RIGHT HERE,
WE SEE THE IONS AND THEN WE HAVE THE SUFFIX CHANGE,
THOSE -IDES, RIGHT?
AND THESE ARE ALL MONATOMIC IONS.
I'D RATHER BE ALONE.
I'D RATHER BE AWAY FROM OXYGEN.
SO THE -IDES LET US KNOW THAT THOSE ARE THE IONS.
SO LINGUISTICALLY,
THERE'S A LOT OF INFORMATION NESTED IN THE SUFFIXES,
SO WE GOT TO PAY ATTENTION.
AND THEN TO PRACTICE THAT, RIGHT?
SO HERE'S SOME EXAMPLES, RIGHT?
SO WHEN WE SEE THIS, THIS IS THE ION CHLORIDE,
AND THEN WHEN WE READ THE WORD CHLORINE,
HAVE NO FEAR OF ICE COLD BEER.
HERE WE HAVE THE ION NITRIDE,
AND WHEN WE READ THE WORD NITROGEN,
WE RECOGNIZE THAT IT'S PART OF THE "HAVE
NO FEAR OF ICE COLD BEER" GANG.
OKAY. SO LET'S GO TO--
AND THAT'S REALLY ALL THERE IS FOR DIATOMIC MOLECULES.
JUST MAKE SURE THAT YOU KNOW THE SEVEN,
SO YOU WANT TO MEMORIZE THAT.
THE NEXT TWO PAGES WILL BE FOR THE BINARY COVALENT COMPOUNDS.
SO BEFORE WE GET INTO THOSE,
LET'S REFLECT ON WHAT WE KNOW ABOUT NOMENCLATURE
SO FAR, RIGHT?
SO FOR IONIC COMPOUNDS,
IT'S ALWAYS A FIXED RATIO BECAUSE THE CHARGE
OF THE IONS HAVE TO BALANCE OUT TO CREATE THE NEUTRAL COMPOUND.
SO FOR EXAMPLE, IF WE READ THE NAME IRON (III) HYDROXIDE,
THIS IS A PERFECTLY GOOD NAME.
THIS ALL WE NEED TO KNOW TO FIGURE OUT THE CHEMICAL FORMULA
BECAUSE WHEN WE READ THIS WE SEE THAT THE ROMAN NUMERAL
IS TELLING US THE CHARGE ON THE FE3+.
AND THEN OF COURSE WE HAVE HYDROXIDE,
ONE THE IONS WE'VE MEMORIZED AND WE KNOW IT'S A -1.
SO THERE'S ONLY ONE POSSIBLY WAY FOR THESE TWO IONS
TO COME TOGETHER TO CREATE A NEUTRAL COMPOUND
SINCE WE'RE ALWAYS GOING TO USE THE SMALLEST RATIO,
SO WE WOULD DESCRIBE THIS AS THE FORMULA UNIT
FOR THE IONIC COMPOUND.
AND, YOU KNOW, AND THIS IS LIKE THE ION--
THE IRON IS LOSING AND THE HYDROXIDE IS TAKING,
AND SO WHEN WE'RE IN A GIVE AND TAKE SITUATION,
THERE'S OFTEN NOT A LOT OF OPTIONS.
BUT WHEN WE GET TO COVALENT COMPOUNDS, RIGHT?
THESE NONMETALS CAN COME TOGETHER IN A VARIETY OF WAYS
BECAUSE THEY'RE SHARING.
THEY'RE NOT GAINING OR LOSING.
AND IF WE LOOK AT OUR OWN LIFE,
WHEN WE HAVE A SPIRIT OF SHARING,
THERE'S A LOT MORE OPTIONS OUT THERE.
SO THE SAME THING IS TRUE OF ATOMS AND MOLECULES.
SO FOR EXAMPLE, ANYONE THAT'S EVER HAD THEIR CAR SMOGGED,
IF YOU LOOKED AT THE SMOG REPORT,
THERE WAS AN ELEMENT--
THERE WAS A CATEGORY FOR NOX EMISSIONS.
SO NOX REPRESENTS THE BINARY COVALENT COMPOUNDS COMPOSED
OF NITROGEN AND OXYGEN THAT CAN EXIST IN OUR CAR EXHAUST.
AND WE CAN SEE THAT THERE'S A TON
OF DIFFERENT POSSIBILITIES.
SO WHEN WE LOOK AT THIS BINARY COVALENT,
NOW WE HAVE TWO DIFFERENT ELEMENTS.
SO THE BINARY IS REFERRING TO THE NUMBER OF ELEMENTS PRESENT.
NOTICE HERE THAT THERE'S DEFINITELY
MORE THAN TWO ATOMS, RIGHT?
ATOMS VERSUS ELEMENTS,
BUT THERE'S ONLY TWO ELEMENTS PRESENT.
SO NOW WE WILL LOOK AT HOW WE WOULD NAME BINARY
COVALENT COMPOUNDS BECAUSE WE SEE THAT THE OLD--
THE IONIC COMPOUND RULES AREN'T GOING TO WORK,
SO THAT'S WHY WE HAVE TO HAVE SOME NEW NOMENCLATURE RULES
AND WE'RE GOING TO USE THE GREEK PREFIXES.
SO IN A WAY THAT--
FOR IONIC COMPOUNDS,
THOSE ROMAN NUMERALS WERE A BIG DEAL,
VERY INTERNATIONAL THIS NOMENCLATURE, RIGHT?
THE GREEK PREFIXES ARE GOING TO BE THE KEY
FOR THE BINARY COVALENT COMPOUNDS.
SO WE'RE-- WE'VE GOT A LITTLE MORE TO MEMORIZE, RIGHT?
SO THE-- THESE GREEK PREFIXES,
THEY SHOULD BE PRETTY STRAIGHTFORWARD,
NOT-- I DON'T THINK THEY'RE A HARD THING TO MEMORIZE, RIGHT?
MONO- OF COURSE WOULD BE ONE, AND DI- IS TWO,
AND WE ALL HAD TRICYCLES HOPEFULLY WHEN WE WERE LITTLE,
TRI-, AND THEN TETRA-, THAT'S FOUR,
FOR THE TETRAHEDRON, RIGHT?
PENTA-, THE PENTAGON, HEXAGON'S SIX, HECT-,
SEVEN, OCT-, EIGHT, OCTET RULE,
NONA-, NINE, DECA-, TEN.
ALL RIGHT. SO YOU REALLY WANT TO GET
THESE GREEK PREFIXES MEMORIZED RIGHT AWAY
AND THERE WILL BENEFITS AS WE MOVE ON TO ORGANIC CHEMISTRY
BECAUSE MANY OF THESE PREFIXES
WILL BE USED AGAIN FOR ANOTHER NOMENCLATURE SERIES
THAT WE'LL BE LEARNING IN THE FUTURE.
SO IT'S A GOOD INVESTMENT OF YOUR TIME.
SO OVERALL, FOR NAMING BINARY COVALENT COMPOUNDS,
WE HAVE A GENERIC STRUCTURE.
THERE'S A GREEK PREFIX THAT WILL--
THAT POSSIBLY PRECEDES THE FIRST ELEMENT.
WE'LL LOOK CLOSER AT THAT ON THE NEXT PAGE.
AND NOTICE THAT IT GETS THE FULL NONMETAL NAME.
ALL RIGHT. SO THIS IS ALL FOR THE FIRST ELEMENT.
AND THEN FOR THE SECOND ELEMENT,
IT WILL ALWAYS HAVE A GREEK PREFIX.
AND THEN WE'LL HAVE THE STEM,
BUT NOTICE WE'RE GOING TO SWITCH TO
-IDE OF THE SECOND ELEMENT.
ALL RIGHT?
SO VERY STRAIGHTFORWARD, STILL TWO PARTS, RIGHT?
SINCE THAT IT'S BINARY,
THERE'S ONLY TWO ELEMENTS PRESENT.
SO THE FIRST ELEMENT LISTED WILL GET ITS FULL NAME.
AND THE SECOND ELEMENT WILL TAKE ON THE
-IDE SUFFIX.
SO, LET'S PRACTICE THAT ON THE NEXT PAGE.
ALL RIGHTY.
SO HERE ARE THE RULES THAT I MENTIONED.
ALL RIGHT. SO WE NAME THE FIRST ELEMENT USING THE PREFIX
TO INDICATE THE NUMBER OF ATOMS.
HOWEVER, LOOK DOWN HERE AT RULE THREE,
WE DO NOT USE THE MONO- PREFIX FOR THE FIRST ELEMENT, OKAY?
AND WE'LL DO AN EXAMPLE OF THAT VERY SOON. ALL RIGHT.
AND THEN WE NAME THE SECOND ELEMENT, RIGHT?
AND WE USE THE -IDE SUFFIX LIKE WE'VE TALKED ABOUT ALREADY.
AND ONE LAST THING, WHEN WE LOOK AT THOSE GREEK PREFIXES,
IF THE GREEK PREFIX ENDED IN A AND WE'RE GOING TO USE
IT WITH OXYGEN OR OXIDE, RIGHT?
WE'RE GOING TO REMOVE IT.
AND I'LL SHOW YOU AN EXAMPLE OF THAT AS WELL.
ALL RIGHT.
SO LET'S LOOK AT THESE EXAMPLES
TO ILLUSTRATE HOW WE APPLY THESE RULES.
ALL RIGHT. SO NITROGEN IS THE FIRST ELEMENT,
SO IT GETS ITS FULL NONMETAL NAME,
AND THERE'S TWO OF THEM SO THIS WOULD BE DINITROGEN, OKAY?
NOW WE LOOK AT THE SECOND ELEMENT,
MIGHT AS WELL COLOR CODE HERE, OKAY?
SO NOW, FIVE, RIGHT?
SO FIVE WOULD BE PENTA-, RIGHT?
BUT WE'RE GOING TO HAVE OXIDE, SO WE'RE GOING TO DROP THE A,
SO THEN THAT WOULD BE PENTOXIDE.
SO THE FULL NAME
OF THIS COMPOUND IS DINITROGEN PENTOXIDE.
ALL RIGHT.
SO THAT REALLY EMPHASIZES RULES ONE,
TWO, AND FOUR, ALL RIGHT?
NOW, LET'S LOOK AT AN EXAMPLE THAT UTILIZES--
ALSO USES RULE THREE.
ALL RIGHT.
SO HERE WE HAVE OUR BROMINE, RIGHT?
AND IT'S LISTED FIRST, SO IT GETS IT'S FULL NAME,
AND THERE'S ONLY ONE OF THEM.
BUT SINCE IT'S THE FIRST ELEMENT,
WE OMIT THE MONO-, SO IT'S SIMPLY BROMINE.
NOW, FOR THE FLUORIDE, RIGHT?
SO IT'S GET THE SUFFIX
AND THERE'S ONE OF THOSE SO MONOFLUORIDE.
OKAY? SO IN BOTH EXAMPLES,
THE FIRST ELEMENT LISTED GETS ITS FULL NONMETAL NAME.
WE USE THE GREEK PREFIX IF IT'S NOT A MONO.
FOR THE SECOND ELEMENT, WE ALWAYS END IT WITH THE
-IDE SUFFIX
AND WE'RE ALWAYS GOING TO INCLUDE THE GREEK PREFIX.
ALL RIGHT.
SO NOW WE'RE STARTING TO HAVE QUITE
A BIT OF NOMENCLATURE THAT WE'RE RESPONSIBLE FOR.
SO HERE IS A TABLE, THIS WOULD BE A GOOD TIME
TO PAUSE THE VIDEO TO DOUBLE CHECK AND SEE HOW YOU'RE DOING.
AND THEN I WILL GIVE YOU THE ANSWERS.
ALL RIGHT. WELCOME BACK.
HOPEFULLY, YOU PAUSED AND TOOK A MOMENT, RIGHT?
SO WHEN WE SEE O2, WE RECOGNIZE THAT AS OXYGEN.
THAT'S THE OXYGEN WE BREATHE BECAUSE OXYGEN IS PART
OF THE "HAVE NO FEAR OF ICE COLD BEER" GANG.
OXIDE, THE SUFFIX LETS US KNOW O2-, ALL RIGHT.
NOW HERE WE HAVE, RIGHT, NITROGEN,
THERE'S ONLY ONE OF THEM,
SO WE SKIP THE MONO.
ALL RIGHT.
NOW, THIS OXYGEN IS NOT A DIATOMIC MOLECULE, RIGHT?
A DIATOMIC MOLECULE JUST MEANS WE HAVE TWO OXYGEN ATOMS.
THIS--
THESE TWO OXYGEN ATOMS ARE PART OF A BINARY COVALENT COMPOUND.
SO IN THIS CIRCUMSTANCE, WE WOULD BE DIOXIDE.
ALL RIGHT.
AND THEN LAST BUT NOT LEAST, RIGHT? CHROMIUM (III),
REMEMBER, THIS IT THE CATION NAME,
SO THIS IS TELLING US WE HAVE CHROMIUM WITH A +3 CHARGE,
AND THEN THERE'S OUR BUDDY OXIDE AGAIN.
AND SO THEN WE'RE GOING TO FIND THE SMALLEST RATIO OF WHOLE--
OF WHOLE NUMBERS TO GIVE A NEUTRAL.
SO WE WOULD NEED TWO CHROMIUMS
AND THREE OXIDES, SO THAT--
THIS WOULD BE THE CHEMICAL FORMULA FOR CHROMIUM (III)
OXIDE, BECAUSE THE ROMAN NUMERAL IS GIVING US THE CHARGE.
ALL RIGHTY.
WELL, THAT CONCLUDES THIS VIDEO
ON BINARY COMPOUNDS AND DIATOMIC MOLECULE NOMENCLATURE.
IT'S ALWAYS A GOOD IDEA TO HAVE A FEW MORE PRACTICE PROBLEMS
TO REINFORCE YOUR UNDERSTANDING.