Why you need to wear safety glasses

In case anybody didn't know why you should wear your safety glasses - and any other personal protective equipment.

If you still need to be convinced, check out the below video's progression from 1:00 - 3:30.

Extinguishing candles with sulfur hexafluoride

Extinguishing candles with sulfur hexafluoride. Or witch craft?

It's pretty straight forward.

Combustion - like the fire on the tiny candles - needs oxygen. Oxygen is slightly heavier than air (because air is mostly nitrogen gas, and oxygen is heavier than nitrogen), but sulfur hexafluoride is way heavier than oxygen or nitrogen or air.

So, the sulfur hexafluoride gas displaces the air, leaving no oxygen for the combustion reaction to burn.

It would be just like filling the large box with water, but you just can't see the sulfur hexafluoride.

Of course, there are problems with freely dumping sulfur hexafluoride out.

XKCD - disaster movie

Source - link

See, it's funny because scientists aren't the big, buff heroes often portrayed in disaster movies as being the people on the front lines leaping into the burning building, driving their trucks at the edge of the tornadoes, cruising around the island saving people from raptors, leaping lava rivers to save their damsel in distress.

Instead, scientists would be more likely to be looking to update their data about the world as the disaster happens. In fact, as explainxkcd explains (natch)...

The situation described (scrambling to update geographical datasets in the advent of natural disaster) is actually a common occurrence these days. The Humanitarian OpenStreetMap Team's Disaster Response unit does almost exactly this: When there is a natural disaster in a location that lacks high quality GIS data (common in much of the developing world), a team of volunteers across the world mobilises to update and improve OpenStreetMap. They use the latest available satellite imagery, usually donated free for the purpose. Disaster response teams then use the GIS data in OpenStreetMap to create maps and plan their response.

Inside the 23-Dimensional World of Your Car's Paint Job

We're continuing this week with a little more on the art theme. It's a very different kind of art from last week's memory metal flower, but there are still pedals involved. (groan)

Wired magazine has a brilliant article detailing the incredible process of color matching the paint on a repaired part of a car to the paint on the rest of the car. At first blush, the process seems awfully simple - pick up a can of the paint used to paint the car originally. Things are a little more complicated than that, however, as no repair shop is going to stock 50,000-60,000 different paints (the number of car colors on the road according to the article), no car in need of repair looks exactly like it did when it first rolled off the production line. and because the original paint job on most cars involves twenty three different dimensions to the color - sparkles, coarseness, red, blue, green, angle, diffuse coarseness, and so on.

The knowledge and skills involved in color matching are absolutely mind-boggling. There's an art to it all.

Aluminum recycling - How it works by Norsk Hydro

We have to recycle more.

There are many countries that are far, far better at recycling than is the US, but we (the US) have to get better.

I hadn't thought about the challenge of not just sorting the majority metals (steel from aluminum from copper from etc) but rather sorting the various similar metal alloys out from each other. The use of x-ray spectroscopy to do that is an application that I would never have considered, and the puff of air used to fire away the unacceptable aluminum alloy chips is amazingly fast.

It's amazing to me how technologically advanced the recycling industry is becoming.

Spinning Sphere of Molten Sodium

I know they're not doing this experiment - "12.5 tons of hot, liquid metal designed to spin at up to four revolutions per second" - because of any chemistry questions. Rather they're trying to explore the creation of the Earth's magnetic field.

But because they're using molten sodium, there are some fascinating chemical reactions that they need to avoid.

So they don't have a normal, water-based sprinkler system to avoid 'modestly catastrophic" because water on sodium, to quote Mr Mackey, 'it's bad, mkay'.

What is the NEW Silver Play Button REALLY made of?!

The video description doesn't remotely need that ?! at the end.

That being said, the process that the youtubers here go through to find out what specific elements are in the 'silver' play button is fascinating. The (?) Energy Dispersive X-ray Spectrometer is something that's new to me.

I'm particularly fascinated by the results at 5:39 showing the elemental makeup at various depths of the 'button.'

Yeah, all that's interesting, but what's the 'gold' play button award made of?

We produce 13 tons of hazardous waste every second

We are horrible to the planet.

And we have to be better.

Otherwise we're going to continue to poison the only environment that we have.

Luckily this Vox video doesn't dwell only on the negative. Instead, they look at what a small startup, Smarter Sorting, is doing to decrease the number of hazardous materials that end up in the waste stream - that aren't incinerated or landfilled.

I'm hopeful that this program expands soon.

Solomon the Unwise

See, it's funny because when King Solomon is known for his decision when two women came to him both claiming to be the mother of the same baby. Solomon suggested that the baby be cut in half with each woman getting half the baby. One mother thought this a fair decision, and the other woman begged for the child not to be cut in half. She was willing to relinquish her claim rather than let the baby die. Solomon then announced that the woman relinquishing her claim must be the real mother because she cared more for the baby's life than for her claim.

In the case of the comic, the two women both claim that be the owners of the atom. King Solomon apparently proposed the splitting of the atom.

Nuclear fission - splitting the atom - releases a massive amount of energy, hence the mushroom cloud.

Source - C-section comics

And there's a bonus panel...

A Periodic Pun Performance

I'm sorry.

Morbid Monday: The Man Who Dissolved His Wife

Breaking Bad might've used hydrofluoric acid to dispose of a human body, but in reality, bases are much more effective.

Take, for example, the story of Adolph Luetgert, a Chicago sausage maker who grew tired of his wife and eventually 'dissolved' her in a vat of potash (a mixture of potassium hydroxide and potassium carbonate).

During a search of Luetgert’s factory on May 15th, a watchman suggested they look in a steam vat in the cellar that was used to dip sausages. The police looked inside, and found that the vat was filled halfway with a putrid-smelling, reddish-brown liquid. When the police pulled a plug near the bottom of the vat, on the outside, the slimy liquid and small pieces of bone fell out. Inside the cauldron, police found a gold ring with L.L. engraved on the inside. Near the vat, investigators discovered a strand of hair, pieces of clothing, and half of a false tooth.

Luetgert is one of many folks who have used acids and bases to dispose of human bodies. In fact, it seems that a process called alkaline hydrolysis is being used in some mortuaries in the US now.

How to Make Rainbow Fire

Do NOT use methanol for demonstrations involving fire.

Seriously, no debate, no maybe, no 'ifs'.

Just don't use methanol at all.

And Heet absolutely is methanol. Their SDS says so. (Interestingly, it actually says it's 100% methanol; between 0.0006-0.0012% some second, proprietary ingredient; and between 0.0001996-0.0003996% some third, also proprietary ingredient.)

Some safety notes from that SDS...

• Highly flammable liquid and vapor - H225
• Keep away from heat, sparks, open flames, and/or hot surfaces. - No smoking. P210
• Ground and/or bond container and receiving equipment. - P240
• Use explosion-proof electrical/ventilating/lighting/equipment. - P241
• Use only non-sparking tools. - P242
• Take precautionary measures against static discharge. - P243
• Do not eat, drink or smoke when using this product. - P270
• Use only outdoors or in a well-ventilated area. - P271
• Container may explode when heated.
• Vapor explosion hazard indoors, outdoors or in sewers.
• HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
• Most vapors are heavier than air. They will spread along ground and collect in confined areas (sewers, basements, tanks).
• Vapors may form explosive mixtures with air.
• Vapors may travel to source of ignition and flash back.
• Structural firefighters' protective clothing will only provide limited protection.
• Move containers from fire area if you can do it without risk.
• LARGE FIRES: Cool containers with flooding quantities of water until well after fire is out.

Seriously, just last week I was at the National Science Teachers Association's national conference in Atlanta listening to a presentation about lab safety. One of the opening statements was that we all know not to do the rainbow demonstration but that there's more to lab safety.

It was just an assumed, opening bit of knowledge that we should've ever do the rainbow demonstration with methanol. There wasn't any explanation given because it should be that obvious. There wasn't even an explanation of what the rainbow demonstration was because it's apparently chemistry teacher res ipsa loquitur knowledge.

Periodic graphics: Water-repelling chemistry

I dig the work of Andy Brunning and am curious whether he's still a chemistry teacher of if he's moved fulltime into the chemistry infographic world.

A mole of moles

Only someone as twisted and intelligent and educated as Randal Munroe would be able to answer the question, "What would happen if you were to gather a mole (unit of measurement) of moles (the small furry critter) in one place?" and to then take the answer to a place where we get a sentence like this, "Plumes of hot meat and bubbles of trapped gases like methane—along with the air from the lungs of the deceased moles—periodically rise through the mole crust and erupt volcanically from the surface, a geyser of death blasting mole bodies free of the planet."

I love Randal Munroe.

Modified sponge mops up oil but not water

"Due to the nature of the industry, cost-effective high absorbents are needed...Any advancement to have high spill sorbent is of use." ~ Seshadri Ramkumar

See, what he's saying is that the oil industry (and the shipping industry and pretty much everybody else) spills oil in the ocean...and lakes...and rivers...and fields...so we need to be ready to soak up the oil.

The environmental impact and morals of our modern dependence on fossil fuels aside, the chemistry here is pretty cool.

Though the name of 'compound 1' seems a little odd to me because I can't imagine that the first compound they tried was their successful attempt. There's a reason why we have Formula 409.

Either way, 'compound 1' attracts to nonpolar solvents like oils but has little to no attraction to polar solvents (like water).

Smartphone "Spectrophotometer"

Sure, but what students of mine would actually have smartphones?

Oh, that's right, pretty much all of them.

It's fascinating to see what we can do with smartphones.

I may have to try this one out myself because AP chemistry now requires a Beers Law lab.

Purity

See, it's funny because scientists are known to reduce other branches of science to being just an applied version of their own. Chemists claim than biology is just applied chemistry, then physicists claim that chemistry is just applied physics and so on.

Then comes mathematics on which all of the sciences are based and which isn't necessarily - at least as far as this comic is concerned - based on any of the other STEM fields.

Plus it has a squirmy, stick-figure-style octopus and a psychologist with a stick-figure, folkster beard. That's inherently funny.

Bond..._____ Bond

See, it's funny because...well...if you don't know the phrase, check out this video.

Hydrogen bonds form between two molecules that have high electronegativity differences between hydrogen and another nonmetal (typically F, N, or O). Hydrogen and the highly electronegative element can get very close to each other due to hydrogen's small atomic radius, so the molecules attract very strongly.

That makes this joke especially ironic because James Bond almost never got emotionally close to any of his co-stars...except Teresa Draco, of course.

The joke has also been made about ionic and covalent bonds...because it's an easy joke to make...

The melting point of gallium is...

See, it's funny because gallium melts at - as the comic caption says - 85.58 degrees Fahrenheit. Body temperature is 98.6 degrees Fahrenheit, so the metal dog would likely melt over night meaning that dad wouldn't have to buy his boy a puppy but will be able to say that it's his boy's fault.

I am thinking, however, that this might be a bad idea, not really because of the toxicity (a pretty minor risk for gallium) but rather because of the challenge of explaining that the gallium didn't technically 'wet' the bed because its intermolecular forces are strong enough to hold mostly together and didn't attract to the bed sheets.

"Glassblowing kits, which taught a skill still important in today’s chemistry labs, came with a blowtorch."

See, it's funny because chemistry sets used to be a thing. In the early 1900's chemistry sets were sold, hoping to promote scientific exploration among young (admittedly pretty much just) boys.

From a Smithsonian article...

The safety-conscious 1960s brought a quick end to the chemistry set’s popularity. The Federal Hazardous Substances Labeling Act of 1960 required labels for toxic and dangerous substances, and chemistry set makers removed the alcohol lamps and acids from their kits. The Toy Safety Act of 1969 removed lead paint from toys but also took its toll on the sets. The creation of the Consumer Product Safety Commission in 1972 and the passing of the Toxic Substances Control Act in 1976 resulted in further limits on the contents of the kits. Newspapers that once broadcast the arrival of new kinds of chemistry sets soon warned of their dangers, recommending that they only be given to older children and kept locked up from their younger siblings. “The death of the chemistry set is almost an unintended consequence of the rise in consumer protection laws,” says Cook.

Sadly, it looks like in the world of the webcomic, all chemicals possibly more dangerous than water have been removed from chemistry sets.

More readings about the decline of the chemistry set

• from Philosophy of Science
• from the BBC
• from Wikipedia

Black hat...always helpful

See, it's funny because there are bunches of websites advertising that they can reduce your car payments, you mortgage payments, your tax bill.

Mostly they want you to pay them so they can help you take advantage of things you could do yourself - like asking companies to help restructure your bills. Be careful out there, folks.

Back to the chemistry, though...

Very few services, however, really help you reduce (in the chemical sense - meaning to have the compound or element gain electrons) your bills. It would be easy enough oxidize your bills in the chemical sense (meaning to have the bills lose electrons) by just burning them, but reducing your bills would be a little tougher.

Though sodium borohydride would be a fine starting point.

1:1 scale

See, it's funny because atoms are really small.

Go ahead, imagine the smallest thing you can think of, the smallest thing you can see.

That's made of more atoms than there are people on Earth.

It's made of more atoms than there are grains of sand on the planet.

Atoms are smaller than you think.

Watch as I turn water into phenolphthalein's basic form!

See, it's funny because most kids would not be excited about the magician being replaced by a scientist.

Then again, the experiment mentioned in the final panel does look pretty cool.

You're part of the precipitate.

See, it's funny because the word solution here means a mixture of a solute (the blue, solid material) and a solvent (the clear or white liquid, assumedly and frequently water). Solution can also mean a resolution to some problem.

See, so making a solution was the solution.

Lick a snozzberry

See, it's funny because sniffing many of the elements would be terribly dangerous.

Some would just be unpleasant: selenium, sulfur, perhaps osmium.

This one isn't exactly too deep.

Shardik would be fine

See, it's funny because the bear in the water is a polar bear.

In chemistry, polar means one side of the species (molecule, usually) has a slight positive charge, and the other side a slight negative charge. This means the polar molecule will attract to water which is also polar.

Non-polar bears (brown bears, black bear, spectacled bears, koala bears, gummi bears) wouldn't dissolve in water.

Though they should be careful about swimming in cyclohexane because it's non-polar, so non-polar solutes would dissolve in it.

Been there...

See, it's funny because boiling pure hydrochloric acid would be awful for the room's occupants.

Admittedly, though, pure hydrochloric acid has a boiling point of -85 C, so it's already a gas at room temperature.

The student might be boiling a solution of hydrochloric acid - which does create an awful smell, something I know from a lab that I do with my students each year in which they synthesize sodium chloride by mixing sodium carbonate and hydrochloric acid. Typically the acid is in excess, so when they boil away the water created, they usually get a very brief wiff of the chlorine gas at the end.

Ideally, it's a very small wiff.

Salty

See, it's funny because NaCl is the chemical formula for sodium chloride, typically known to most folks as table salt.

I would, however, take a half point off of the soup for having written the symbols in all upper-case letters.

It's NaCl not NACL.