Stoichiometry Tricks

This is a whiteboard animation tutorial of how to solve Grams to Grams Stoichiometry problems.
Please support me on Patreon:
/ ketzbook
In this video, I work through a complex and relevant stoichiometry problem in which I show how much carbon dioxide is produced when 1 gallon of gasoline is burned. I explain every step, and I show how to simplify the three step math problem into a one step math problem. There are also several tricks that I use to help my students remember what goes where in the conversion factor fractions.
Tricks for 1 step grams to grams stoichiometry conversion:
1) write "1 mol" in the top left and the bottom right
2) in the bottom left goes the molar mass of what you start with
3) in the top right goes the molar mass of what you are solving for
4) in the middle fraction goes the chemicals with their coefficients from the balanced reaction
5) numbers on the bottom of fractions always correspond to what you are starting with
6) numbers on the top of fractions always correspond to what you are solving for
This is my third tutorial in the series.
My goal is to make chemistry easier ;)
ketzbook.com
#chemistry #madeeasy #stoichiometry #ketzbook #tutorial

[@mr.b6551]

"Here's 12 of these questions, you have 15 minutes to complete the quiz" -Chemistry teachers

[@FreeSoloPCgamer]

Sounds like my Steel design professor but with problems way harder and longer

[@deniserobles9253]

top left and bottom right always have to have 1 mole bottom left goes the molar mass of what you start with and the top right has to have the molar mass of what your solving for in the middle section goes the coefficients of the chemicals from the balanced reaction

[@VKVK-bb8ql]

Thank you so much, We can even short down it. The above equation 2C8H18. Gives. 16CO2 then 228grams of 2C8H18. Gives 704 grams of 16CO2 THEN 2800 grams gives 2800×704÷228 Which gives 8600 grams of CO2

[@calistawaddell512]

1) Write down the balanced chemical equation 2) Calculate the molar masses of the chemicals 3) Convert mass to moles of what you know 4) Convert moles of what you know to moles of what you want to know 5) Convert moles to mass of what you want to know 1 Mole This tells us the other part of the fraction is a molar mass conversion factor 00723

[@myraflores4608]

Anyways, your videos are always helpful! And your voice does not makes me feel sleepy.

[@altheagordon7183]

Thank you very, very much for your explanation on Stoichiometry. After weeks of trying everyone, I never knew I would find someone like you to help me. I am so happy because I have my exam coming up later today. Thank you.

[@justinalloway1405]

A new trick I learned was that when a number in a balanced equation is not whole multiply the whole thing by 2 - 00401

[@henryroa1729]

I learned more in 6 minutes than 2 hours worth of BS video lectures from my professor. you are a god send!

[@user-ut5nx6hm9d]

Ok I wish I'd found this videos earlier.

[@joeybfitness991]

The conversion factor between one chemical I another is the balanced chemical decided by the other chemical. A trick I learned from this is the mole divided by the molar mass of the chemical mirror each other on each side.

[@TheMan-cf9yf]

Thank You So much

[@rebeccamerritt6001]

The balanced reaction is used to convert the molar mass of the chemical we were starting with, in this example octane, to the chemical we were looking for, carbon dioxide. The balanced reaction is needed to take into consideration how many of each molecule is needed in the complete combustion. 00115

[@jakekart55]

It's used between the two unit conversions of moles and grams. The thing you are solving for is multiplied and the thing u have is divided.

[@redlight7718]

you are the best thank you so much

[@meganperdue2865]

The balanced equation is used between two unit conversions of moles to grams, 00415

[@kokopium7761]

I absolutely love you

[@atiqazubairi3382]

THANKYOU SO MUCH SIR THIS VIDEO HELP ME ALOT TO SOLVE SO MANY TRICKY QUESTIONS THANKYOU

[@ketzbook]

you're welcome!

[@oliviaalloway6869]

the numbers from the balanced reaction, the chemical solving for goes on the top and the balanced reaction is on the bottom

[@kirashort1895]

1 mol is always in the top left and bottom right. This figure reminds us that the other half of the fractions are molar masses. The number on the bottom left is the molar mass of what we're starting with, while the number on the top right is the molar mass of what we're solving for.

[@savannahfaulkner5874]

top left and bottom right always have to have 1 mole bottom left goes the molar mass of what you start with and the top right has to have the molar mass of what your solving for and the middle section is the coefficients of the chemicals from the balanced reaction 00410

[@jordin407]

00815: You use the balanced reaction in stoichiometry to determine the relative number of reactants and products

[@drewd2696]

The middle fraction are the numbers from the balanced reaction the chemical we are solving for goes on top and the one we are starting with goes on the bottom 00802

[@mssmiley85]

Thank youuuuuuuu

[@hueyt3323]

The chemical that you are solving for goes on top and the balanced reaction goes on the bottom, using numbers of elements, from a balanced reaction, 00421 (Elijah Tull)

[@0nobody379]

the balanced reaction is used between the 2 unit conversions of mols and grams. The thing you're solving for is multiplied at the top and the thing you have is divided and the 2 numbers are used as coefficients. 00205

[@sheilaescamilla4767]

It is used between the conversions of moles and grams, 00715

[@cierrasouthard6532]

1 mole is always in the top left and the bottom right, this tells us that everything in between are molar masses. the fraction in the middle comes from the balanced equation itself. 00823

[@kaiblackwell2086]

You lost me at “welcome” lol

[@myraflores4608]

Why I get 8632 and something when I calculate it? What could be the problem?

[@manaloaaron7256]

Me to even the scientific calculator agreed

[@briannagrace182]

This is the reason I won’t fail my quiz tmr

[@johnwycliffe.chindada9482]

❤️ u........thank u soo much 🙏

[@khubaibuddinsimran4930]

He's sooo underrated

[@stephaniedalit573]

Life saver

[@ketzbook]

:)

[@MAndy-sw8rb]

00403: Bottom left- molar mass of what you are starting with, important because it corresponds to what you start with Top Right- molar mass of what you are solving for, important because numbers on top correspond to what you are solving for

[@madankumarsingh1598]

Thank you for saving ma life

[@ketzbook]

you're welcome!

[@madankumarsingh1598]

@@ketzbook omg can't believe it's you. Thank you once again

[@kasiyahtatem7946]

1 mol always goes in the top left and the bottom right because it reminds us that the other portion is the molar mass, 00418

[@makaylaleigh7729]

I learned how to combine the three equations into one large conversion ; 00101

[@dustinbeideman9168]

1 mol. Reminds us the other half of the fractions are molar masses, 00103

[@mylezhudson7324]

Balanced reaction is in the middle of the three parentheses

[@lendyfuentes2082]

1mole is at the top left and the bottom right. Reminds us that the other half are molar masses

[@rhyno17]

1) Write down the balanced chemical equation 2) Calculate the molar masses of the chemicals 3) Convert mass to moles of what you know 4) Convert moles of what you know to moles of what you want to know 5) Convert moles to mass of what you want to know Grams to moles 00407

[@rebeccaarpie9184]

ID:00404 The excess mass of the Carbon Dioxide came from the Oxygen; this is why its mass is larger than Octane's.

[@sierrahfindeison3092]

You use the balanced reaction as your conversion factor, 00110

[@MiguelSantiago-tr4ff]

In the middle of the fraction, the Chemical we are going for goes on top, and chemical we start out with goes on bottom, 00217

[@teganshockley2047]

we use the chemical we start with on the bottom and the chemical we are solving for goes on the top, 00417

[@alexispascual8187]

1 mole is always in the top left and also the bottom right. This tells us that everything in between is considered the molar masses. 00818

[@colehatton9784]

you put the balanced reaction into the middle of the three parentheses

[@colehatton9784]

008334

[@islerdonnesha]

Your balanced equation is the conversion factor in the moles to moles equation

[@rosingh8425]

The chemical that's getting solved goes on the top and the balanced reaction goes on the bottom right, 00608

[@amycraft6993]

1 mol goes in the top left and bottom right. This tells us that everything in between are molar masses - 00108

[@bayleeketterman3620]

the coefficients of the chemicals from the balanced reaction. 00412

[@irhamf7636]

oh god oh god oh god oh god , this is so helpfulll !! i believe u can beat khan academy way more better ! u solv 6 yeas problemmssss. thanksssssss

[@tiapersolio322]

1 mol goes in top left and bottom right conversions, 00416

[@DoplerEffect]

00803] 1) 1 mol in TL and BR 2) this "reminds us that the other half of those fractions are molar masses"

[@daejahjackson-powell7096]

Instead of having three separate calculations, you can combine the three conversions., 00811

[@gabrielgalaviz8398]

How he get 44.01 ?

[@briehagen1254]

I learned how to combine three equations into one big step, 00806

[@kirbygedalanga4402]

Why the O becomes 25 please explain

[@christianrothermel6487]

In the middle fraction, the chemical we are going for goes on the top and the chemical we have goes on the bottom, 00607

[@erykbluto2468]

The numbers from the bottom reaction, 00702

[@reaganlittle6431]

1 mol, this reminds us that the other half of those fractions are molar masses. 00813

[@ricky-11]

Anyone else here cuz their teacher made them watch this vid then do notes?? Smfhhhhh😭💀😂😂

[@rachaelbreneman8572]

1 mole it reminds us that the other half of the problems are molar masses, 00703

[@y2k68]

Balanced reaction, 00707

[@ZioTrickz]

I learned how to put 3 fractions into one to make the problems easier., 00821

[@kaylynndick9344]

The mass of Co2 is larger than the mass of octane bc of the large amounts of oxygen compared to hydrogen in octane, 00409

[@elianrodriguez6206]

because octane was being burned in excess air, the mass of oxygen made the mass of CO2 larger than Octane, 00824

[@abbyswearer5408]

the chemical you are solving for on top and the balanced reaction on the bottom,984311

[@sabrinacardarelli6486]

Balanced Reaction 00107

[@alphatangowhiskey7600]

i learned to combine 3 equations into 1 big one, 00206

[@raynelawrence7546]

balanced reaction, 00812

[@guadalupevasquez8859]

love the trick!! Too many steps makes me not want to do it. Much thanks! xoxo

[@ketzbook]

you're welcome!

[@johnkopp780]

The percent Yield is 0.8 percent, 00606

[@agustinjaysoncadag]

Sir, I think that should be 8, 632 and not 8, 600?

[@edgarfernandocortesespinoz3706]

did someone else solve the balance equation diffrent? Igot C8H8 + 10O2 = 8CO2 + 4H2O

[@ashleymartinez2466]

The mass of CO2 is larger than the mass of octane because of the excess air, O2, 00114

[@JewBoiZ96]

00716 I learned to use 3 steps in one

[@dylanarmiger6643]

i learned to combine 3 equations into 1 big one, 50678

[@kaitlinhitchens679]

the mass of carbon dioxide is larger than the mass of octane. 00111

[@karnaejackson5136]

Balance reaction 00112

[@EternalSmite99]

The mass of CO2 is larger because when the 2 Octane molecules are burned it creates 16 CO2 molecules (a much larger amount) 00610

[@graysondoesgaming1330]

Chad 🧡

[@alisawarren2096]

Because octane is being burned in excess air, 00609

[@tarynwood7017]

because CO2 has the higher molar mass in the equation 00224

[@davinperez3194]

1 mole, and tells us that half of the other factors are moler mass

[@RYanimayyyyy31]

The mass of CO2 is larger than the mass of octane because of the large amount of oxygen compared to the hydrogen in Octane. 00814

[@princessjones5185]

It is more oxygen in octane than hydrogen, 00209

[@brookeparker7332]

CO2 is larger due to the amount of oxygen which makes it 3 times bigger than the mass of octane, 00214

[@yaritssaparada7881]

The mass of CO2 is larger than the mass of octane because the extra mass came from the oxygen, 00119

[@trevorbowden7341]

oxygen makes the mass larger for carbon dioxide while octane is burned excess air. 00104

[@jillianwharton1442]

Its larger becuase CO2 has such a bigger mass, which is why it overrules octane, 00724

[@donnyconquest3085]

because of the oxygen in the carbon dioxide, 00204

[@shelovesRH]

Because CO2 has a larger molar mass 00709

[@Rubester11]

00414 Hydrogen weighs less than oxygen

[@clairetrimble8439]

CO2 is larger than octane because of the excess air, 00419

[@J_o_k_e_m_a_n]

FIRST!!!!

[@sharvesh0369]

it is not 8600g co2 it is 8624g of co2

[@ketzbook]

significant figures my friend, significant figures. There are only 2 significant figures, so it is 8600.

[@waltersobchak7275]

@@ketzbook What's up with all the repetitive comments in this comment block?? Are they your students?? By the way nice videos, and website. You are a natural bro. 👨‍🎓👨‍💻🔬🔎📚✏👍💯🎓🤓

[@ketzbook]

@@waltersobchak7275 yes, some of these were my students answering a hw in the comments.

[@waltersobchak7275]

@@ketzbook Thanks Professor Ketz.

[@karapowell4359]

CO2 is larger because of the amount of oxygen compared to octane. 00719

[@sanatani_manushy77]

Anyone from India!!

[@Omg.itsmonica]

Anyone else get 8632g of CO2??

[@sebastianlahens292]

It’s not 8,600 it’s 8632.43 your wrong

[@ketzbook]

As I mentioned at 4:39, there are only two significant figures, so although mathematically you may be correct, scientifically you are incorrect. The answer should have only 2 significant figures. And by the way, it is "you're" not "your."

[@alejandroochoa862]

​@@ketzbookHi. I have a question, should be just one significant figure for the 2 C8H18 isn't ? Thanks.

[@ketzbook]

no, the 2 is a counting number, not a measured value, so it is known exactly (infinite sig figs)