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Soup in a can – a lesson in exothermic reactions.

Monday, April 13th, 2015 | EMILY HALL | No Comments

A while ago, a friend gave me this can that she had been given as a novelty prize somewhere somehow.

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Anyway, because it was “science-y” she thought I might enjoy it.

I must admit it’s been sitting on the shelf for a wee while. Mostly because every time I look at it and think I should try it out, something else comes along to distract me. Also due to being vegetarian for most of my life, the contents of the can have never really screamed my name. Recently though, I have heard advertisements on the radio for a similar or possibly the same product. I decided to pull out the can and give it a try. I don’t eat meat so I decided to use my carnivorous children as taste testers.

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The can itself feels squishier than a regular can, like it is covered in foam under the label. I think the indicators on ours were not working because, as you can see, although the instructions said they would turn from black to green, both indicators were white initially.

Before we started, I went to the hotcan website to find out what was in there to produce the heat (water and calcium oxide) mostly because I wanted to cut the can apart after the experiment and didn’t want any chemical burn surprises

Pushing in the bottom of the can made a popping noise immediately.

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Shake it like a polaroid picture. We shook the can the required amount of time and then set it on the bench as specified in the instructions. Almost immediately, the can began to dance on the kitchen bench and steam was billowing out the bottom. (I told the kids to get back because I actually thought it was going to blow, thankfully this stopped fairly quickly)

After waiting the required time and using the ultra scientific method of feeling the can with our hands (broken indicator, remember?) we decided it was done and had a look/taste.

Reviews of the soup were favourable. The temperature was hotter than expected (said the tasters) there were no chunks, just a smooth soup. Taste was what you would expect from tinned soup. The boys did mention that there was less soup in the can than they had expected. The reason for this became clear when we opened up the can.

IMG_2364Inside the can you can see there is a cylinder coming up through the centre of the can – presumably this is so the soup heats from the middle to the outer layer. The foamy consistency of the can is a layer of insulating foam between the label and the can which would help with the soup heating, staying hot, and not burning your mitts off when you hold the can.

When we took the bottom off we saw this:

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Slightly hard to see from the image but it is like a bladder of what I assumed was water originally surrounded by a chunky white powder.

 

 

 

I asked the children (12 and 11) as I was writing today (2 days later) what if anything they had learned/remembered from this whole experience.

  • Water and calcium oxide produce heat which is transferred to heat the soup. You have to shake it to make it work better
  • When you burst the water packet, the water seeps into the calcium oxide, they must have measured the water and the calcium oxide so it produces only a certain amount of heat

An interesting and easy little experiment!

I found this Limestone Lesson Plan on the Royal Society of Chemistry website and thought it could be paired with the hot can for a great Chemistry lesson. Look at the Chemistry of Limestone lesson (which includes heating the limestone to make calcium oxide and then testing it with water to see the exothermic reaction) and then apply the knowledge to how the hot can product works.

 

 

 

Chemistry detour…

Tuesday, March 31st, 2015 | EMILY HALL | No Comments

Chemistry

 

My next post was going to be on the chemistry behind the hot-can and I am part way through what I think is a neat little experiment/lesson involving this cool (or hot rather) invention. Today though, I was derailed by another Chemistry resource!

I’ve been a fan of MIT (Massachusetts Institute of Technology) open courseware for a while and I used snippets of it with classes and the OUASSA tutorials last year. I especially recommend their Highlights for High School where you can pick a topic and subtopic and be directed to a specific resource that may help you. Meaning for example, you don’t have to watch the whole lecture series on Classical Mechanics to help you in your struggles with Projectile Motion, the folks at MIT have pulled the relevant bits out of their screeds of material and collated it all for you. I must admit though to being so focussed on the Physics resources available, I was missing this little gem.

Chemistry Boot Camp is a multi episode show that follows 14 students as they go through a three week intensive lab course at MIT. The show is compelling for two reasons, first, it offers a glimpse into what life is like as a student at MIT and second, there is some really cool Chemistry going on. What I liked most about the show was that instead of just glossing over what the students were doing, there was an effort made to explain the Chemistry behind what they were doing and why.

The episodes are short – only 5 minutes ish in length and not counting the bonus episodes there are 11 in total, I managed to binge watch the entire series in a lunch break. A nice light Science meal to set up your afternoon.

 

 

Cool resource for Physics and Chemistry

Monday, March 31st, 2014 | EMILY HALL | Comments Off on Cool resource for Physics and Chemistry

websiteI ran across this website a couple of years ago but for some reason didn’t use it at all.

http://www.gpb.org/chemistry-physics

On the site is a complete course in Chemistry and a complete course in Physics for high school level in Georgia, USA. They consist of a series of videos, one on each topic listed with note taking guides and study guides. The videos are only about half an hour long and come with a problem set based on the video.

I am going to trial one of these in class today and also show the girls the link in the hopes that they might use the videos at home for their own revision. I was thinking too it might be a good activity for them if I am away so they can still move forward with their learning even when I am not there. We have a set of netbooks they can use and watch the material on their own if the reliever doesn’t have a laptop to show the whole class at once.

Fun Friday Films!!

Friday, April 19th, 2013 | EMILY HALL | No Comments

The school holidays are upon us and while you students are busy with work, fun and hopefully some study, I’m sure there’ll be times when you think to yourself “boy, I could sure do with a serving of Science right now!”. Well you are in luck because someone recently suggested one of these 3 minute films to me and I found myself watching more and more of them. And for teachers, I showed a couple to my class yesterday at the end of the period and they really enjoyed it. They are interesting little snippets that can serve as a good starting point for discussion and only 3 minutes long so not a huge investment of time.
http://focusforwardfilms.com/ is the website
This one http://focusforwardfilms.com/films/78/you-don-t-know-jack appealed to the students as it is about a 14 year old boy who makes a breakthrough in cancer testing.
My 10 year old son was particularly fascinated with this one: http://focusforwardfilms.com/films/30/solar-roadways where they talk about a new way to “pave” the road with solar cells!

Anyway I’ve managed to watch maybe 1/2 dozen of the films on here and haven’t yet found one that I didn’t think was cool on some level.

Another film site that I’ve been sent at least 3 times in the last little while is one by astronaut Chris Hadfield on the ISS.
http://www.youtube.com/user/canadianspaceagency?feature=watch
He has videos on all kinds of things from making a sandwich in space, to sleeping in space, toothbrushing in space to wringing out a washcloth in space!! Again cool Science of everyday objects and good starting point for discussion! I really hate flying but Chris Hadfield makes me want to be an astronaut it looks like the most amazing “job” ever!!

Have a happy safe holiday to all the students and teachers!!

Grab a steaming cup of 1,3,7-Trimethyl-3,7-dihydro-1H-purine-2,6-dione…

Friday, April 12th, 2013 | EMILY HALL | No Comments

So this week I went looking for some cool chemistry resources. I stumbled into the Royal Society Chemistry page and found a couple of things I thought were really cool!

First – Feb 2016 marks 175 years of the Society and one of the things they are doing is a 175 faces of Chemistry. Little bios of Chemists and their lives. They reminded me a little of the Applications books where they use a real life example of someone doing something cool to explain some Science and I thought maybe they could be useful to get kids thinking about the relevance of Chemistry to them. The one I thought was super cool was a high school Chemistry teacher turned Fireworks guru – insert explosive learning puns here! Anyway – check them out: http://www.rsc.org/Membership/175-faces-of-chemistry/

Also on the website, they have resources for teachers, I took a quick stroll through those and I am going to use the one about the 100m race and acid/base chem in my Year 10 class next term. They are nice because they are ready to go ppt and notes with worksheet etc but also I was thinking with the 100m one it is loose enough we can add in some things as we go. All their resources are here: http://www.rsc.org/learn-chemistry/resource/listing?searchtext=&fcategory=all&filter=all&Audience=AUD00000001&displayname=teachers

And finally, the part of the site that dragged me furthest away from any useful work and perhaps proved to myself yet again what a massive nerd I am was the ChemSpider. This is the neatest little tool – you type in the name of a chemical (it was almost morning tea time so I started with caffiene) and it gives you the name, formula, 2d and 3d pictures as well as links to papers written about your substance of choice and all kinds of other useful information. Very easy to spend a lot of time in here exploring chemicals around us!! Fall down that particular rabbit hole here: http://www.chemspider.com/

And that is all from me for now, I have to get back to chemspider!!!

 

Particles

Monday, May 23rd, 2011 | KEV KNOWLES | No Comments

This achievement standard involves describing properties of atoms, molecules, and ions, and thermochemical principles.

Properties of particles include:

  • electron configuration of atoms and ions of the first 36 elements (using s,p,d notation)
  • special characteristics of transition metals (variable oxidation state, colour) related to electron configuration. Transition metals will be limited to iron, vanadium, chromium, manganese, copper and zinc
  • periodic trends in atomic radius, ionisation energy, and electronegativity, and comparison of atomic and ionic radii
  • Lewis structures and shapes (up to six electron pairs about the central atom for molecules and polyatomic ions, including those with multiple bonds)
  • polarity of molecules
  • attractive forces between atoms, ions, and molecules. These will include ionic bonds, covalent bonds, and intermolecular attractions due to temporary dipoles and permanent dipoles (including hydrogen bonding).

Thermochemical principles include:

  • transfer of heat between the system and the surroundings
  • calculations involving the use of specific heat capacity
  • ΔcH°, ΔfH°, ΔrH°, ΔvapH°, ΔsubH°, and ΔfusH°
  • Hess’s Law including application of ΔrH(= ΣΔfH((products) – ΣΔfH((reactants)
  • bond enthalpies.

Equilibrium

Monday, May 23rd, 2011 | KEV KNOWLES | No Comments

This achievement standard involves describing properties of aqueous systems using equilibrium principles.

Aqueous systems are limited to those in which proton transfer occurs and those involving a sparingly soluble ionic solid.

Properties of aqueous systems are related to the nature and the concentration of the species present in the solution. Description, explanation and application, or discussion of these properties may be qualitative and/or quantitative.

Qualitative evidence may include

  • correlation between acid or base strength, Ka and pH
  • relative equilibrium concentrations of dissolved species
  • variability in solubility of a sparingly soluble salt due to the formation of a complex ion, the addition of a common ion, or the reaction of a basic anion with added acid
  • features of titration curves including buffer region, equivalence point and selection of indicator (titrations of weak acids with weak bases are excluded)
  • the nature of buffer solutions.

Quantitative evidence includes calculations involving

  • Ka, Kw and pH limited to
    • solutions of bases, monoprotic acids and buffers
    • those in which the extent of reaction is small so that the equilibrium concentration of a dissolved weak acid can be approximated by the initial concentration, ie [HA] = c(HA)
    • pH at a particular point in a titration;
  • Ks and solubility limited to
    • AB, A2B and AB2 type solids where neither of the ions A or B react further with water
    • calculating the concentration of one ion given the other
    • calculating the solubility in water and in solutions already containing one of the ions A or B (a common ion)
    • predicting precipitation or dissolution.

Redox

Monday, May 23rd, 2011 | KEV KNOWLES | No Comments

This achievement standard involves describing oxidation-reduction processes.

Processes involve reactions and calculations, which may include electrochemical cells and their properties, the use of reduction potentials, and spontaneity of oxidation-reduction reactions.

Calculations may include determination of oxidation numbers, mole ratios and those related to electrochemical cells.

  • Knowledge of appearance and state of the following reactants and the product to which they are converted in an oxidation-reduction reaction is required.
  • Oxidants will be limited to: O2, Cl2, I2, Fe3+, dilute acid (with metals), H2O2, MnO4– (reacting in acidic, basic or neutral conditions), Cu2+, Cr2O72–/H+, OCl–, concentrated HNO3, IO3–, MnO2.
  • Reductants will be limited to: metals, C, CO, H2, Fe2+, Br–, I–, H2S, SO2, SO32–, S2O32–, H2O2, H2C2O4.
  • Appropriate information relating to other oxidants or reductants will be provided.