In 3 and a half minutes you explained what 15 pages of instructions couldn't. Thank you!

7 years later this video is still highly appreciated.

Taking intermediate environmental chem and still didn't know what I was doing with this one. Absolute chad, you're a hero Mike.

You don’t even know how much of a saint you are to me right now!! Thankyou!!

@Toalettduck

6 жыл бұрын

lol bro same here, fucking assignment

What a life saviour, even four years later during a pandemic hahahaha TYSM!!!!

THANK YOU!!!! You simplified this so much to understand!!! Life saver!!!!

Thank you so much, explained in 3 minutes what I couldn't get in hours.

You are an angel for ones that cannot make an equation curve. Thank you

Wow. Thats what i was looking for. So simply explained. Thank you.

2 weeks before the big lab test and you saved me! Thank you man

Absolute life savior man! Thank you loads!!

Straight to the point and well explained. Thanks!

Dude...you are my friggin' hero.

Heros get remembered; but, Legends never die. Fantastic content sir 👏👏👏

Simple explanation, so useful. Thanks so much!

Absolute lifesaver mate!

Super frumos si practic ai explicat. Multumesc frumos!

Thank you ! It's very helpful.

Thank you! This helped a lot!

This video rocks, thank you

Thank you! Your video helped me, to do my job. :)

Thank you for this!!

Thank you very much. Nice explanation

thank you for your awesome tutorial

thank you man it was realy helpfull

appreciate you, king

This video helped so much with my lab. Thank you!!!

I appreciate this video thank you

Thank you this is so helpful

SAVED MY LIFE

Thank you! very helpful

Thank you so much!!!

you are a king

Really good video!

Thank you so much

Thank you so much.

thanks so much! it helped me with my report essay

Thank you!!!

Hey man, nice video! But I wonder how much important is the R-Squared value (Coefficient of Determination probably). Should I divide the final unkown concentration with the R-Squared or multiply? I cant find it anywhere on the internet and I have exam in few days. Thank you in advance!

This is great! If my calibration curve is emission% (e.g. sodium) with concentration (ppm) and i want to find the sodium mg/mL, do i follow the same steps?

sir video helps a lot. our teacher explains it in a very bad manner. person like is boon to students all over the world.

Thank you for that very straight forward explanation. How do you plot that unknown concentration on the calibration graph?

@d9e240

4 жыл бұрын

After calculating the concentration in molarity (as he demonstrated in the video) I added the "unknown" (now known concentration and molarity) to the two columns on the left, I created a new chart. I had to rewrite the axes and title but no big deal. I'm sure there is an easier way, but it worked for me.

Appreciated!

Can I use same method for GC-MS sample concentration calculation by placing area instead of absorbance i.e. by plotting concentration vs area graph. Then is it ok to calculate sample concentration using y value of trend line as discussed here.

Thanks a lot....

Thank you

Thanks!

Thanks a lot

nice explanation

thank u ❤️❤️❤️

Hi friends, I am using HG-C 1100 sensor and this sensor measures the range from -35mm to 35mm. I have doubt in using the formula float val = (float)(map(samplse,0,1023,-3500,3500)/100.0);. I have to take the readings from the sensor and should display it in the serial monitor. The values also should be accurate as in the sensor. Can anyone explain me how to take the formula and calibrate the same? Thanks in advance

factor calibration .how many valor it can have ?

from where u get y value 0.125?

@mikedavis6274

5 жыл бұрын

That was my absorbance of my unknown solution. I got it in lab. It is a solution I could get the absorbance of, but didn't know the concentration of.

If I diluted 10ml of my unknown to 100ml would I have to multiply it by 10?

@medinaxoxo

5 жыл бұрын

yes

can you explain why you multiplied the unknown by 10 at the end? is it because it was originally in a 100ml flask and then you pipetted 10 ml from that into a new 100mL flask?

@mikedavis6274

7 жыл бұрын

That is right. In this lab, my students had to dilute something by a factor of 10, so we end up multiplying by 10 at the end.

In case of y=mx-c..we can use this type of standard curve for calculation or not? ...please reply me sir ..its urgent

@mikedavis6274

2 жыл бұрын

You should be able to, yes. Ideally c would be zero or at least a very small number because the absorbance should be minimal when the concentration is zero.

King

What if we measured absorbance for each concentration twice, how would we be able to plot that?

@mikedavis6274

21 күн бұрын

I have a couple thoughts, but first, I would recommend asking your teacher what they recommend. (1) You can take the average of the two absorbance readings. I assume it is the same solution, so you may have run it twice to get the average. (2) You can plot two lines. This could potentially give you another slope, and another answer in the end. (1) is my advice, but I would recommend asking your teacher.

I love you

Can u plz tell what should I do to find the concentration at the end if I have used 25 ml sample for the test? the last portion I felt confused?

@mikedavis6274

7 жыл бұрын

Do you mean you diluted a 25mL sample to 100mL? You would multiply the answer by 100 and divide by 25 or basically multiply by 4.

@sarmilakhanal4745

7 жыл бұрын

No for ammonia test I applied phenol method for the test. No dilution is operated over here? how can I extract its concentration?

@mikedavis6274

7 жыл бұрын

Can you use the email address in the video to send me your procedure? Its hard to know without knowing a little more about what you did.

@sarmilakhanal4745

7 жыл бұрын

its ok I got the soln thanx .. the video helped a lot

how did you get 0.125 as the absorbance?

@mikedavis6274

Жыл бұрын

That is a reading that came off the instrument.

Please I'm unable to label my graph on my laptop. Please help me out

How do you get the absorbance, I have the raw data from my concentrations from the UV/Vis spectrometer.

@mikedavis6274

4 жыл бұрын

Usually the numbers you get from the spectrometer are unitless absorbance or transmittance numbers

@ayshab2123

4 жыл бұрын

@@mikedavis6274 I did the ratio of know concentration over zero to get absorbance to create my calibration curve but it's not linear at all. I don't know what exactly I did wrong😨

@mikedavis6274

4 жыл бұрын

So you had a known concentration, diluted it and ran it through the instrument? What numbers did the instrument give you?

@ayshab2123

4 жыл бұрын

@@mikedavis6274 for each concentration it gave me a number for each wavelength, like at wavelength 380.5 it had absorbance of 1.206, this continues until wavelength 899

@ayshab2123

4 жыл бұрын

I honestly think it's the machine I used. Mabey because it's cheaper.

How did you get the 0.125?

@mikedavis6274

6 жыл бұрын

It was an absorbance for an unknown solution that was similar to what my students were using in lab.

@Cristelle731

6 жыл бұрын

I got it! Thanks!

I'm doing a homework assignment where we are given a graph and the concentrations. I plotted concentration vs absorbance and did all the calculations and got 1.4884E-05? Do you need to multiple it by 10 or was that just for your example?

@mikedavis6274

5 жыл бұрын

My students had to dilute their sample by a factor of ten, so in the end they had to multiply by ten. If you didn't dilute, you don't need to multiply.

@jackmiller7324

Жыл бұрын

I need to do this too lol

If I diluted 10ml of my unknown to 25ml would I have to multiply it by 10?

@mikedavis6274

4 жыл бұрын

No. If you diluted your sample 10:25, you would multiply it by 25/10 or 2.5. You diluted it because it was too concentrated.

@jessicaledesma5533

4 жыл бұрын

@@mikedavis6274 So, first when I prepared the unknown I diluted it by a 1:10 factor. Then, I diluted it again by a 10:25 factor. So, I have to multiply by 2.5?

Where did you get 140.33 ?

@mikedavis6274

6 жыл бұрын

That number (140.33) is the slope of the best fit curve through those points. Excel calculated it. You can also get it by picking an empty cell and typing in =slope(. It will prompt you to highlight your known y's, and then your known x's. So it would look like this for the example we just did. =slope(B2:B5,A2:A5). That will return the slope for you.

@cluelesstuber7352

6 жыл бұрын

Mike Davis 😊

I don't understand why the absorbance 0.125?

@mikedavis6274

4 ай бұрын

That was a number I made up for my unknown's absorbance. You should use whatever your unknown's absorbance was.

Clutch bro

do not we need to measure blank sample?

@mikedavis6274

Жыл бұрын

No. Your blank is essential zero. There is zero concentration so there is zero absorbance.

@asedefp175

Жыл бұрын

@@mikedavis6274 thanks for the answer. If I measured the blank, it shows little absorbance. In that case, can we subtract the blank from the analyte absorbance? If blank has absorbance, then how to write 0 absorbance at 0 concentration?

is this the same as a absorbance curve?

@mikedavis6274

7 жыл бұрын

Branden Williamson

@mikedavis6274

7 жыл бұрын

Yes, it is. You use known concentrations to find an unknown.

@brandenwilliamson5183

7 жыл бұрын

Mike Davis thank you!

when your prof on analytical chemistry teach also statistics....

It is still giving me wierd graph even after following each step.

@mikedavis6274

3 жыл бұрын

It could be the data. Send me your file or data.

My line goes the opposite way

@mikedavis6274

3 жыл бұрын

That's odd. What is your data?

MIke you are a life saver I want to kiss you. Thank you for helping me solve my reports (University of Nicosia)

u should pass by zero to do this !!!!!!!

Thank you! This is very helpful

Thank you so much