Lab Skills: Preparing Stock Solutions
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- čas přidán 23. 07. 2024
- in this video I walk you through the process of preparing a stock solution.
00:00 - Introduction
00:57 - Obtaining the molecular weight of your reagent
02:10 - Calculations (How many grams do you need?)
04:09 - Using the scale
05:52 - Selecting the right beaker
06:62 - A note about water: use the most pure water available to you
07:06 - Making the actual solution
08:09 - Proper use of a stir plate
10:09 - Bringing the volume up to the desired amount
14:21 - Using Parafilm
Thank you so much. It helped me a lot ☺
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GRAT , REALLY HELPED
THANK YOU
Thank you. That was SUPER helpful! I start my new job in a research lab tomorrow. :)
Best of luck!
@@ItsLearnable Thank you! It is going really well.
Thank you sir ,🙏
Most welcome
Thanks very much
At least i have learnt on how to handle every equipment in a lab
Great to hear!
How many gram of K2Cr2O7 does it require to produce 0.1N of the compound
Thank you very much, Sir. Please how many grams of Ni should I use to prepare Nickel Chloride stock solution using 500ml and 1000ppm?
Calculating PPM solutions is a little different, and I don't often see it in Biology labs, hence I don't have any videos on this. But questions like this have been answered in many other places. Here's an example: www.quora.com/Whats-the-procedure-to-prepare-1000-ppm-Na-solution-using-NaCl
You can actually calculate the molecular weight, for example:
Nacl: Atomic mass of (Na = 22.98 u ) and (Cl = 35.5 u) which is on the periodic table or is generally the double of atomic num (Atomic number of Na = 11 and Cl = 17) so by adding atomic masses (NaCl = 22.98 + 35.5 = 58.48 g/mol)
That's true, but not all reagents in the lab can be calculated in this way.
Some compounds may have some H2O molecules associated with them even in the "pure" form that you receive from the supplier. This affects the formula weight of the compound and will cause your calculations to be inaccurate if you just rely on using the periodic table. It is always a good idea to check the reagent bottles in your lab for the formula weight - just to make sure your calculations are correct before weighing anything out.
If 50mL of our stock was created initially, why did we add water as the remaining 50mL to top up to 100mL? Or was did this second 50mL also contain 5.84g of NaCl?
Please keep in mind that this video is meant as a general protocol for making just about any solution - not just a 1M NaCl solution.
I this case, I added 50ml of water at the end because the calculations were made for 100ml. So, if I didn't add the 50ml, my concentration would actually be 2x as high as it should be.
I ask students to start with about half the volume, when learning to make solutions, because I want them to develop that habit.
Sometimes, when making solutions, you need to adjust the pH. In those cases, the act of adding acid or base, will change the volume, so you need to make sure you leave "room" for that.
By developing the habit of starting with a lower volume, you avoid the problem of overshooting the total volume in solutions you need to pH.
isopropyl alcohol 99.9 is this product same as ssd solution is it with same purposes that can be usdd to clesn etc
Do you mean SDS?
No it's not the same.
i will use it for papers and do you have chemical for any kind of color that i can remove colors from papers with your chemical
I'm not quite sure what you're asking for.
This is just a video showing how to make solutions in general.
It really helped
Please, can you make a video on Normality preparation. This video is For Molarity only
Hi, sorry for the late reply.
This video goes over the general protocol for making a solution. It doesn't really focus on the calculations that much.
I don't currently have a video on calculating normal solutions (partially because I see Molar solutions used far more commonly in a molecular biology lab), but this site explains it fairly well: www.labce.com/spg931723_what_is_a_normal_solution.aspx
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