Chemistry - Unit 6 Flashcards

LAST UNIT OF THE TRIMESTER WE GOT THIS U GUYS

LAST UNIT OF THE TRIMESTER WE GOT THIS U GUYS

I BELIEEEEEVEEEE

okay, so this unit deals w/ a looot of numbers

so buckle up and get ready for lots of practice, and refer to the resource page too!

back to the basics: tell me, what is the number for a mole of particles?

6.02 hexillion, or 6.02 x 10^23

what is the format of scientific notation?

A x 10^B

what does "B" represent in scientific notation?

the # of decimal places to be moved

what is the purpose of scientific notation?

to reduce the number of zeros in big big number, u don't wanna deal with that

when writing in scientific notation, how many numbers should be in front of the decimal?

one. just one.

alright alright now POP QUIZ: write 93,000,000 in scientific notation. GO!

9.3x10^7

now for our fav thing ever...

sig figs....yay...

let's ask ourselves because we might be asked on the test: what are significant figures, and why do we use them?

• #of digits or figures that give reasonably reliable info

• used to show how precise a # is

what that actually means...idk u tell me

now the thingy about sig figs is their special rules, so let's get into those (flip the card)

I'll give you a rule and you tell me whether it does or doesn't represent a sig fig

nonzero integers, ie: 1,2,3,4, etc.

sig fig!

trailing zeros: zeros @ the right end of the number w/o a decimal point (ie: 2900)

NOT a sig fig

leading zeros: zeros that come before the nonzero digits (ie: 0.000038)

NOT a sig fig, only there for the ~aesthetic~

captive zeros: zero held hostage in between nonzero #'s (ie: 207609)

sig fig!

exact numbers: numbers not obtained by using measuring devices (ie: 1 day= 24 hrs)

NOT a sig fig

trailing zeros: zeros at the right end of a decimal (ie: 3.00)

sig fig!

what is percent composition?

the percentage of each material found in a compound (by mass) equation: mass of element/total mass x 100

BOO! ANSWER THIS QUESTION: what is the percent composition of nitrogen in copper (II) nitrate?

about 14.94% Nitrogen

now for ur fav: dimensional analysis!!!!!?!?!?!!??!!

i'm so tired

tell me, wth is dimensional analysis?

literally just converting from one unit of measurement to another

easy right?

W R O N G

to get a better understanding of dimensional analysis, tell me, what are conversion factors?

fractions with numerator and denominator of EQUAL value

how do we use conversion factors to get to new units of measurement?

multiply the fractions by putting the unit you want to cancel out on the denominator of the next fraction ie:

true or false: you can convert from moles,->grams

true

yuh or nuh uh: you can convert from atoms

yuh

yahoo or boohoo: you can convert from grams

BOOHHOO. YOU MUST HAVE MOLES FIRST. WHY? IDK I FORGOT BUT REMEMBER THAT.

now for that new stuff we were taught but weren't rlly taught since she wasn't here to teach it

empIRICal and mOleCular FormULas OmG I loVE thEM

wuts molecular formula?

formula that gives the total number of atoms of each element present in a compound

ok now what's empirical formula?

the teensy tinest ratio of atoms present in a compound, kind of like reducing the subscripts to the smallest amount

OK I THINK THAT'S AB EVERYTHING THAT WORKS W/ FLASHCARDS GO LOOKIE AT THE RESOURCES FOR PRACTICE AND NOTES AND STUFF HAVE A GOOD DAY