Titration is a procedure for determining the concentration of a solution. And so let’s say we’re starting

with an acidic solution. So in here let’s say we

have some hydrochloric acid. So we have come HCl. And we know the volume of HCL, let’s say we’re starting

with 20.0 milliliters of HCl. But we don’t know the concentration right? So question mark here for

the concentration of HCl. We can find out that concentration

by doing a titration. Next we need to add a few drops

of an acid base indicator. So to this flask we’re also going to add a few drops of an acid base indicator. We’re gonna use phenolphthalein. And phenolphthalein is colorless in acid but turns pink in the presence of base. And since we have our

phenolphthalein in acid right now we have a clear solution. There’s no color to it. Up here we’re gonna have

our standard solution right? We’re gonna have a known

concentration of sodium hydroxide. So let’s say we have a

solution of sodium hydroxide and the concentration is zero

point one zero zero molar. And we’re ready to start our titration. So we allow the sodium hydroxide to drip into our flask containing

our HCl and our indicator. And the acid in the

base will react, right? So we get an acid base

neutralization reaction. HCl plus NaOH right? If we think about the products,

this would be OH minus, this would be H plus, H plus and OH minus give us H2O. And our other product we would

have Na plus and Cl minus, which give us NaCl, or sodium chloride. So let’s say we add a

certain volume of base right? So now this would be higher, and we see our solution turn light pink. Alright so let’s say we see

our solution turn light pink and it stays light pink. That means that all of the acid has been neutralized by the base. And we have a tiny amount

of excess base present, and that’s causing the acid

base indicator to remain pink. So a tiny excess of base means we’ve neutralized

all of the acid present. And where the indicator changes color, this is called the end point

of a titration, alright? So when our solution changes color, that’s the end point of our titration. And here we stop and we

check and see the volume of base that we used in our titration. So if we started right here, if we started with that much base, let’s say we ended down here, alright? So we still have a

little bit of base left. And this would be the volume of base that we used in the titration. Alright so we have a

change in volume here, and let’s say that it’s 48.6 milliliters. So it took 48.6 milliliters of our base to completely neutralize the

acid that we had present. And so we can now calculate

the concentration of the HCl. Alright so let’s go ahead and do that, and let’s start with the

concentration of sodium hydroxide. Alright we know that we started with point one zero zero molar

solution of sodium hydroxide. So point one zero zero molar. And molarity is equal to mols over liters. Alright so this is equal

to mols over liters. And our goal is to figure

out how many mols of base that we used to neutralize

the acid that was present. Alright so we can take our

volume here, 48.6 mililiters and we can convert that into liters. Alright so just move your decimal place three places to the left. So one, two, three. So that’s point zero

four eight six liters. So this is equal to mols over zero point zero four eight six liters. And so let’s get some more space. Alright let me just rewrite

this really quickly. Zero point one zero zero is equal to X over zero point zero four eight six. So we’re just solving

for X, and X represents the mols of sodium hydroxide

that were necessary to neutralize the acid

that we had present. Alright so when you solve for X, you get zero point zero

zero four eight six mols of sodium hydroxide used in our titration. Next you look at the balanced

equation for what happened . So if I look at my balanced equation alright there’s a one here and there’s a one here. So we have a one to one mol ratio. And the equivalence point is where just enough of your standard

solution has been added to completely react with the

solution that’s being titrated. And at the equivalence point, all of the acid has been neutralized. Right? So it’s completely reacted. And since we have a one to one mol ratio, if I used this many mols

of sodium hydroxide, that must be how many mols

of HCl that we had present in our original solution. So therefore, I can go ahead

and write that I must have had zero point zero zero four eight six mols of HCl present in the flask

before we started our titration. Right and I knew that because

of the one to one mol ratio. Remember our goal was to find

the concentration of HCl. The original concentration. And concentration, molarity is equal to mols over liters. So now I know how many mols of HCl I had, and my original volume of HCl was 20 milliliters right? So right up here we had 20 milliliters. So I need to convert that into liters. So I move my decimal place one two three. So I get point zero two liters. So now our final step here to calculate the concentration of HCl, right so the concentration

of HCl is equal to how many mols of HCl we have, which is zero point zero

zero four eight six mols, over liters of solution. And we had 20 milliliters

which is equal to zero point zero two zero zero liters. Alright so now we can

take out our calculator and do this calculation to find the concentration of HCl

that we started with. Point zero zero four eight six, all right and we’re gonna divide that by point zero two zero zero. And we get zero point two

four three for our answer. So the concentration of HCl is equal to zero point two four three molar. So we’ve solved for the

original concentration of HCl. There’s a shortcut way to do this problem, and the shortcut way would

be to do the molarity times the volume of the acid is equal to the molarity times

the volume of the base used. So MV is equal to MV. So let’s say we have the

acid over here on the left, and the base over here on the right. So the molarity of the acid

is what we’re trying to find. So I’ll just make that X. The volume of the acid

that we started with, you can just leave this in

milliliters if you want, 20 point zero milliliters is how much of the acid we started with. And for the base, we

knew the concentration of the base that we used

in our titration right? It was zero point one zero zero molar. And we also knew the volume of base that we used to completely

neutralize the acid. We used 48.6 milliliters. And notice how the mLs

would cancel out here. Right and we can just

go ahead and do the math and solve for X. So we get out the calculator,

and we need to multiply 48.6 times point one zero zero. Alright and so we get four

point eight six obviously. And then if we divide by 20 we will get our answer of

zero point two four three. So X is equal to zero

point two four three molar. And this shortcut way works pretty well when you’re dealing with a

strong acid and a strong base and a one to one molar relationship. Alright in the next video

we’ll do a problem where the mol ratio is no longer one to one.

God bless

Please keep this up it is so helpful

Wow. Super clear and helpful. Thank you.

Thank you 🙂

is the same process still used if the conc. of the base is unknown? 🙂

Thank you.

thanks…

u helped me so much thank you for everything ! 😀

thanks

Thanks, very clear and understable

i hate chemistry with a passion

Chemistry is the bane of my exsistence😭😭

Is the simplified method -MV base =MVacid only applicable when the reactant mole ratio is 1:1 ?

What would be really helpful would be a video only showing examples which are visual with all three acid-base titrations.

best ever video on titration!!!!!

it was good 2nd method is more easy😊

👍👍👍

Thanks for the video, just one question: is it possible to find the opposite to this, NaOH concentration? using the same method seen in this video? For instance, If I know the concentration of HCl and I need to find the concentration of NaOH?

very well explained, thankyou

I don't understand why the last step of MV=MV is necessary, I thought what that 0.243 mol L-1 is just the answer .

Is the molarity of NaOH 0.1000 M always constant?

When you went to find the concentration of HCL, why didn't you use the formula concentration = mass/volume? Wouldn't that have worked? Concentration's unit is in grams per cubic decimeter or in mols per dm^3

I love you

Hi, I'm trying to perform a titration to find the average amount of lactic acid concentration in yogurt and how much is in a certain amount of bacteria(such as streptococcus thermopilus). I am confused on what my standard solution would be, pls help?

thank you for this

thanks a lot thats was amazing !

What is the program you used?

wait this is still confusing.. i have test tomorrow can anyone please give me a helping hand

can u not do like 5.00000000 with like a billion zeros for no reason plz

calculators aren't allowed in my country

Thank you

3 weeks until the end of chemistry! I am so freaking done with school this year. I am loosing my sanity!

thank you very much this helped me alot

Why can't my teacher actually explain stuff to us like this is stead of giving us packets with reading

these types of videos are the bane of my existence.

THERE SO FUCKING BORING

Chemistry's born to mess with minds…….:(……………titration calculations were easy though…..:P

Real life question. What good is it to know the molarity of an acid if it's already been neutralized?

I'm guessing it was only a sample of acid. Idk. Anyone?

Thank you for uploading this video. Really helped me out..

With the help of khan academy I will survive exams.

Needless to say that my teachers are so unqualified😑

this is realy so helpful…thanku sir….

I study in one of the best schools of my country but I develop my understandings only through online vids…

Not all heroes wear capes 😅

I mean… Why did my chem teacher give the class a titration concentration table the day before a test for review without explaining it? Why does this look a little complicated, what am I doing here, why wont they let me sleep, why am I pulling an all nighter for this test, why did he give all the review the day before the test? Im going to be okay 😀

thank you for this video, I've just begun IB HL chemistry and it was already getting stressful, this video helped a lot!! thanks!!!

I fucking love you!!!!!

i think a more suitable indicator would be methyl orange

great video btw

Gr8 video thanks helped a lot

ASDFHFJGKGKGL I just need to accept im getting a C in Chem. But it’s fine. I’m fine. EVERYTHING IS FINE GODDAMMIT

AS level killed chemistry for me

I do not like chemistry

why the fuck people don't subscribe this channel it's very important channel at least more important than those Paul's Chanel

I love the subject chemistry! Just not the way its taught.

I didn't understand what a standard solution, equivalence point, and that stuff was about – even though I got taught that in chemistry but I still don't understand it 🙁

I was so happy with this as a link to show my students until you got to 7:30 and told them it's acceptable to use M1V1 = M2V2. You don't START with the context that it works only for 1:1 reactions and that it is not an acceptable general case for titrations. Most of the time, students stop watching after they figure out the way to do the problem! I suffered through EIGHT YEARS of titrations being set up as dilution problems regardless of the mole ratio, and this just perpetuates that error. You have to present the context FIRST, or, better yet, don't present the method that way at all!

I thought to find the concentration your need to c=n/V??? you seems to C=nxV??? i dont get this

very nice…👍

the different colors just make it so much interesting

will the short cut way still work if the mole ratio were different

It woulda been nice to have known this before taking my ap chem test yesterday

I think 0.0200L can be written as 0.02L…..

Please increase the volume next time.

Lol the moment he took out the calculator

What the fuck

You assumed early on that I knew how to "Solve for X" now I can't move forth with the rest of the video #whygodwhy #nowIknowwhyoneshowtheirwork

can you not do this in two steps using ratios?

20ml : 48.6ml

0.1 moles : x moles

20/0.1= 200 so 48.6/200= 0.243 M

or will this not work every time?

What's different from [HCl] and X ?لماذا لم نبقي تركيز الحامض[HCl] نفسه لتركيز (X) ?

Please choose me…

Thanks for explaining 😊😊

Only if teachers would bloody earn more, so that you'd get competent teachers. Students have review systems but teachers dont. Fuck all teachers who suck.

why did you divide by 4.86 by 20?

48.6 ml is 0.0486 L not 0.00486

this was so helpful! i'm so grateful thank you very much !!

Much easier way is mass times volume of acid = mass times volume of the base. You will get the same answer

i fucking love you khan academy

Really thank u

Who's here for AP Chem?

The whole video can be summarized as M1V1=M2V2

Stupid teacher couldn't explain this for a week yet I get a clear understanding in a few minutes. Screw paying for school. I want a refund from my University. FML.

I prefer the short cut method of MV=MV .The problem is that it only applies wen the mole ratio for both is 1:1.anyway thanks❤

you're not sal

thank you i finally understand this shit. i still hate it but i can pass my exams.

I love how I already graduated w/ a B.S. in biology and I understand these issues so much more AFTER I am done with school. Now that I'm studying for the MCAT and actually watching videos all of these topics make so much more sense. Hate that I didn't apply myself in school. Fantastic vid.

have a lab due in a couple hours hope i can learn this fast

How did he know what the molarity of the base was?

Amazing video thank you

Fantastic Video!!! I was stuggling with this concept but now I understand.

Please dear : if we have water tank has avolume of water 25000 liter ,and pH=4 ,And i want to add sodium hydroxide to the tank until reach pH=7…determine concentration of sodium hydroxide that you added to keep pH=7??

Im so glad I only need one class of chemistry, ive always hated it

you're better at this than my teacher

You forgot to say that in order to find moles we multiply liter per M

Thank you so much, this really helped me! 🙂 🙂 🙂

Isn't it much more straightforward to use C1V1=C2V2 and solve for the missing HCl concentration?