Pipetting 2: Pipette harder: Behind the scenes

The great feedback we received for our first take at pipetting made our lives a lot easier for our second attempt, so first off thanks to everyone who shared their opinions! Really, the only question we still had to answer before we could start filming our second set of videos was should gloves be worn?

  • The pro-gloves side believe that wearing gloves protects you from not only the chemical you’re working with, but also against the possible contaminated glassware and communal areas of the lab (such as the sink and bench).
  • The anti-gloves side believe that wearing gloves not only makes students complaisant and somewhat careless when it comes to handling the solutions , but also practically gloves impede the controlled release of solution.

“The Hands”(Amy) decided that since the chemical we were using was rather safe, she would go bare-handed, allowing her better control of the release of solution. We thought it noteworthy to mention at the start of the video that if gloves are needed the students will be told in their lab manual.

After “The Voice”(Euan) recorded the script and ensured many rolling Scottish “r”s throughout, it came time for editing. We wanted the videos to be as condense as possible so that the students would pay attention from start to finish, and so I (“The Director/Editor”) abandoned Windows movie maker for Camtasia version 8 which allowed for split screens and callouts.

Hopefully you enjoy our two newest blockbusters!

Pipetting 2

Hi everyone, here are our two new videos on pipetting (graduated and volumetric). Unfortunately due to technical issues the two videos have the watermark associated with the free trial of Camtasia but this is an issue that should be resolved soon. We’ve updated the script for the two new videos which you can find here, and our Behind the Scenes post should be up soon!

Any feedback would be very much appreciated – especially on the introduction which we will standardise once all the videos have been made!

The first graduated pipetting attempt:

The second volumetric pipetting attempt:

Preparing a Standard Solution from Solid – Improved Video

Hey everyone! This is my second post on making a solution from solid. After getting quite a lot of feedback on the previous video, I went back to the lab and re-shot it. This took a longer while and made me realise how many little mistakes you can’t see and how helpful the reviewers are in spotting them.

Photo.jpgAs I said, I re-shot the whole video using sodium carbonate instead of sodium hydroxide, as the latter one may confuse students (carbonate is a primary standard, while hydroxide is not!). I followed a similar protocol to make a 0.1000-molar solution of it, but I changed the way of transferring the solid to the flask. In the previous video, I transferred it directly from the boat. In this video, I transferred it to a beaker first, and then to the flask. I also added a bit about cleaning the balance and leaving it clean after using it and mentioned the purity of the solute. Again, as in the previous video, it is emphasised that one of the most important parts is to transfer the solid quantitatively – which basically means rinsing almost everything with deionised water. Summarising, this is a whole new video – quite different from the previous one. I hope I managed to include all the important details, there are definitely more of them in this than in the sodium hydroxide video.

After the feedback, I will hopefully move to post-production, in which I will add text (checklist for students and important parts to notice) and I’ll try to cut the video a bit, as the long parts tend to get boring. I will also add the opening of me saying: “Hey everyone, this video is about making a standard solution!” (this will go straight after the Edinburgh Uni intro).

I want to thank you all for your comments so far – they were invaluably helpful. Please share your thoughts on this video in terms of mistakes or what I can improve. Feedback on quality, procedure or anything else will be much appreciated and I’d definitely like to get any feedback on the quality of audio (and if my accent is understandable), as I find it the most difficult bit. Enjoy watching!

Preparing a Solution from Solid NaOH

Photo for Post.jpgHi again! While the titration video is waiting for the post-production, a new technique video is ready. This is preparing a solution from solid. Again, the first thing was to find good resources – these were Vogel’s Textbook of Quantitative Inorganic Analysis and the IUPAC Gold Book (standard solutions). I thought that despite that sodium hydroxide is not a primary standard, the main point is to teach the students how to prepare a solution from solid, and that sodium hydroxide would match the video on titration quite nicely. It is emphasised in the video that this is not a standard solution, and that it has to be standardised (titration with a secondary standard as titrant).

So the video is on making a 0.100 M NaOH aqueous solution. As for titration, the protocol was the first thing to do – I wrote down the procedure and the main points to remember. Generally, the main thing was to transfer the solid to the flask quantitatively, which basically means to rinse with deionised water everything that had contact with the solid. Work in the lab was quite smooth and didn’t cause trouble – especially that all the quality issues were solved in the titration video.

The video I’m sharing with you now is the first, rough version. It has the audio and I hope it’s easy to follow. Please note, that the video will be re-shot with sodium carbonate instead of hydroxide, as I want to avoid any confusion with regard to using NaOH for standard solutions. Sodium carbonate is a primary standard and hence will leave no doubts. However, I wanted to share this video anyway, as the procedure for Na2CO3 will be pretty much the same. So please tell me if you find any mistakes and I’ll avoid them in the second version – the one with carbonate. One doubt that I’ve had is whether gloves should be used. For 0.1-molar NaOH there is no need, but solid NaOH is a different story – is it dangerous enough to use gloves though? Of course, this question is easy for carbonate and for that video I won’t be using gloves.

So yeah, please let me know what you think. As I said, the solid will be replaced with sodium carbonate but this won’t change the procedure much. Enjoy watching!

Will the Project Work in Practice?

It is a very important part of developing any project to receive feedback on what others – especially those involved – think about it. So, apart from all the feedback we get for our videos, we also want to make sure the overall project is top notch – that’s what we aim for. And of course, we value the opinions from everyone – teachers, academic staff and the people of YouTube and WordPress, who found out about the project (or those who just procrastinate before exams 😉 ). But if you think about it – the most important group of people – those who will have to learn something valuable from the videos and get the most of the project – are STUDENTS. So  we invited some to our Uni…

On Thursday, May 26, a group of five high school students came to have a look at what being a Chemistry student feels like. So we prepared an activity similar to the one that first year students will do. They were going to carry out a titration of HCl with NaOH – the one I did in my titration video.

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Firstly, the students prepared a 0.100-molar solution of NaOH, which then they used as titrant. We showed them the video and asked them to write down the major points to remember when preparing and carrying out the titration. Then, while doing the actual titration, they were asked to have an eye on each other. After finishing and doing the calculations, they watched the video again, to check if they did everything correctly. They shared their observations and filled a little survey about the project that we had given them.

The survey included a question about the video, whether they enjoyed the activity, what was easy and hard about it. It turned out the students really did like it and thought it was a good idea to develop such a project. They pointed out poor quality of the video, which then was improved (version 2 is the improved one). Unanimously, did they wrote that making and following the checklist made it easier to carry out the titration.

To conclude, the students gave us some really good feedback on the project. Will it work in practice for the first year students at University? Hell yeah!

Titration Video – Version 2

Hello everyone! This is my second post on titration, in which you can see the latest version of the video. First, let me remind you briefly what I did last week. I found reliable sources on this technique. Those were the Vogel’s Textbook of Quantitative Inorganic Analysis and Polish National Chemistry Olympiad, which covered both theoretical and practical aspects, respectively. Then I wrote a protocol with the main points that I wanted to include in my video. This was really helpful in organising work in the lab. I made the first video, which I shared with you a week ago. All that is included in my first post.

Post 2The key word for this week of my internship was quality. I was working on improving the video. I basically re-shot all of it a few times, with different camcorders and settings to obtain the best quality. It took a while, but as it is the first video, finding the best device was a crucial task. I think I’ve overcome the technical difficulties quite well and I’m sharing with you the latest version of the video. It has the audio now, and it’s more or less the version I aim for in the end.

So, how does this version differ from the previous one? Very much. Apart from the previously mentioned audio and text, I added the opening, changed the way of showing the apparatus from photos to the camera slowly panning across it. I also improved the overall quality (I hope!).

I want to thank you all for your comments on the previous video – they were invaluably helpful. Again, I need your help with this one – please share your thoughts on this video in terms of mistakes or what I can improve. Feedback on quality, procedure or anything else will be much appreciated. Enjoy watching!

The First Edit of Titration Video

The first week of my internship is finished and so I’m sharing with you what I was working on and what I managed to do. I’ve been introduced to the first topic – titration. Fairly simple, isn’t it? Wrong! Titration is all about the details and making mistakes makes the results unreliable. This is why I had to approach the task with care trying not to make any.

Photo for blogThe first thing I did was search for resources that I could use. I was shown the Vogel’s Textbook of Quantitative Inorganic Analysis which I decided to be one of my references for titration. It has really well written theory and instructions on specific titrations, as well as descriptions of apparatus. However, not very much practical guidance on the technique could be found and thus I had to search a bit further. The practical aspects of titration were brilliantly described by the Polish National Chemistry Olympiad, including detailed information on what mistakes to avoid and what to pay particular attention to.

After reading literature, I wrote a protocol that would help me organise the work in the lab. I listed all the main parts of the procedure and all the do’s and don’ts. Then I went to the lab and started filming. This bit was really challenging, as was not only about doing things right, but also filming it in such way that would show everything clearly, which I hope I managed to do. I had to do quite a few trials and get comfortable with being filmed until I had sufficient amount of material to choose from.

I then made the video, which I’m sharing with you now. This is a rough first edit and will definitely be improved. Some parts need to be re-shot. This includes: adding the opening with myself introducing the topic and changing the way of showing the apparatus from series of photos to the camera panning slowly across it, as well as showing the meniscus at the eye level. Hence, I’m hoping to get feedback from you before I come back to the lab. I’d be grateful for any comments and advice on what to improve or on any mistakes found. Please note that the audio will be recorded separately and added to the video. If you find it hard to follow what’s on the video, please find the detailed protocol below it.

Enjoy watching and please share your thoughts in the comment section!

TITRATION PROTOCOL

  1. Introduction – PowerPoint slides
  2. Equipment
    • Show equipment
    • Clean equipment
      • Pipette – rinse it with water and leave in vertical position to allow it to drip, dry the external walls with clean paper, if no droplets are present inside, the pipette is clean, there is small amount of water near the tip, and that can be discarded using the paper
      • Burette – same procedure
      • Conical flasks – rinse with distilled water several times, adding small amounts at a time, there is no need for the flasks to be dry
  1. Pipette the titrand – hydrochloric acid – into flask
    • Rinse the pipette with acid – never from the bottle!, suck little acid into pipette, rotate in hands to make the acid flush the walls, discard into waste beaker
    • Pipette right amount – first above the 10 ml level, dry external walls with clean paper, discard drop-by-drop to reach the 10 ml level (meniscus)
    • Empty pipette into flask – touch the wall vertically to empty pipette, wait for 30 secs to make sure everything went into flask, do not attempt to get everything into flask (pipette is to deliver!)
    • Rinse everything (the point where pipette touched flask) down the flask with water
    • Add water – ca 10 ml (cylinder – no need to be accurate)
    • Add indicator – 2-3 drops, the same amount for each of the 3 titrations
  1. Fill burette with titrant – sodium hydroxide, use funnel to pour more easily
    • Rinse the burette with base – open the tap and pour three 10 ml portions of the titrant into the burette
    • Close the tap, fill the burette with base over the “0” level and open the tap to adjust to “0” (take out funnel first), remove the drop from the tip
  1. Titration – always swirl the flask
    • 1st titration – overshooting – add 1 ml at the time and check if colour changed
    • 2nd and 3rd titration – the last 1 ml drop by drop (can use the first flask to compare)
    • Take 2 volumes and if the difference is no more than 0.1 ml, take average
  1. Calculations – PowerPoint slides