The Let's Play Archive

SpaceChem (2013 Tournament)

by Wild M

Part 2: The Chem in SpaceChem - Round 1

I’m planning to release one of these every few days or so (depending on how much time I have), that way it won’t take too long. If you want to ask any questions about the chemistry subjects I cover (or you'd like to add something or correct me), please do so while the thread is still open. Alternatively, you can ask general chemistry questions in the SAL Chemistry thread.

The Chem in SpaceChem, Round 1

Note: As 'The Chem in' Rounds 1 – 4 were written after the tournament, they may refer to later rounds.

1: Fructose factory
Inputs: Dihydroxyacetone, Glycerol
Outputs: D-fructose

First, I like to mention that the input molecules aren’t complete. They each miss an H. It makes it easier to bind them together in SpaceChem, but I’ll just ignore the missing atoms.

Dihydroxyacetone, DHA, 1,3-dihydroxypropan-2-one, C3H6O3
Melting point: 75 °C, 167 °F (I think. Some sources list 90 °C)
Boiling point: 214 °C, 417 °F (predicted)
Molecular mass: 90.1 u
Density: 1.3 kg/L (predicted)

I talked a bit about DHA already during Closed Tournament Round 1. As I said there, any compound with the formula CxH2yOy is called a carbohydrate (carbon + water). And as I said there, DHA is used as a skin tanner.

It has more uses, though. It’s found in sugar beets and sugar cane and has a ‘sweet cooling taste’. If fructose is metabolized, one of the products is DHAP, phosphorylated DHA. It plays a role in the metabolism of glucose, and it also has some use as a medicine, mostly related to carbohydrate chemistry. One page notes it is added to blood preservation solutions in order to maintain the level of 2,3-BPG (a compound that is important for oxygen transport) in stored blood.

Propane-1,2,3-triol, Glycerol, Glycerine, C3H8O3
Melting point: 17 °C, 62 °F
Boiling point: 287 °C, 548 °F
Molecular mass: 92.1 u
Density: 1.26 kg/L

At room temperature, glycerol is a sweet-tasting, colorless, odorless, viscous liquid. Glycerol can be prepared from fats, as those are usually triglycerides, which are esters of glycerol with fatty acids.

Glycerol is a versatile little molecule. It is used in foods as a sweetener and as a solvent. It is also used in many personal care products, as a smoothener, lubricant or humectant (to keep things moist). For instance, it’s used in cough syrup, toothpaste, skin creams and soap. In the form of a suppository, it’s used as a laxative. In the human body, it’s mainly used to make new fat molecules in the liver and in fatty tissue.

Glycerol can also be used as anti-freeze, and has been used for car anti-freeze applications in the past. Car anti-freeze usually contains ethylene glycol, as that compound works better. However, glycerol has the advantage that it is non-toxic. Another important use of glycerol is as a chemical precursor/intermediate to a large number of compounds.

D-fructose, Fruit sugar, 1,3,4,5,6-Pentahydroxyhexan-2-one
Melting point: 103 °C, 217 °F (Some sources list it at 120 °C. Yay, unclear resources.)
Boiling point: I think it decomposes after melting.
Molecular mass: 180.2 u
Density: 1.7 kg/L

Fructose is a rather common sugar with, of course, a very sweet taste. It’s found in honey, fruits, flowers, berries and most root vegetables. Fructose usually adopts a 6-membered ring shape, both in the solid form and in solution.

The D in D-fructose has to do with the stereoisomery form of the (acyclic) shape. Multiple other stereoisomers are possible. I talked about isomery in round 7, but sugars have a kind of isomery called enantiomerism or ‘mirror-isomerim’. Fructose is a chiral molecule with multiple asymmetric carbons. The capital-D and capital-L nomenclature for enantiomerism is a bit strange. The D and L in principle stand for dextrorotary and levorotary, the direction in which the molecule turns polarized light. However, D-fructose turns light left (counterclockwise as seen by someone towards whom the light is travelling). That’s because the D- nomenclature is based on the spatial position of the atoms. If a molecule has a similar structure to right-turning glyceraldehyde, it’s called D- regardless of its optical properties.

As a natural occurring sugar, it’s usually eaten directly. Common table sugar (sucrose) is a dimer formed from one glucose and one fructose molecule. Alternatively, yeast will metabolize it into carbon dioxide and alcohol. The process by which fructose is metabolized in the human body is rather complex, but it can include both of this puzzle’s input molecules.

Feasibility of the reaction
Feasibility: High.
I’m not the best at predicting organic reactions and it’s hard to find any information on how to synthesize a compound like fructose, which occurs a lot in nature. Why bother making it in the lab? In any case, it is possible to form both input molecules by metabolizing fructose, and I can’t directly see any reason why this reaction couldn’t be reversed.

It might not work in one go, you might need a few steps at the right conditions with certain catalysts and intermediates. But my guess is that there should be a way.
In practice, I’d choose to burn glycerol and DHA down to CO2 and water, and feeding that stuff to some fruit plant, which will turn it into fructose for me.

Reaction energy: Very slightly endothermic, about 5 kJ/mol.
That’s a tiny difference in chemical energy. For comparison, the heat of combustion of fructose is 2810 kJ/mol. As it’s just a predicted value, I’d say this value is so small it can’t be considered significant at all.


2: Misfortune modifier
Inputs: Sodium chloride
Outputs: Sodium chloride

Sodium chloride, Table salt, Halite, NaCl
Melting point: 801 °C, 1474 °F
Boiling point: 1413 °C, 2575 °F
Molecular mass: 58.4 u
Density: 2.2 kg/L

Sodium chloride is the best-known salt. Its ions form a cubic structure, and in its natural mineral form halite (also known as rock salt), you can see the cubic structure clearly:
It is also a rather pretty mineral, if you ask me.

Sodium chloride occurs naturally in mineral deposits (often dried up seas). It’s the main salt dissolved in oceans and it is a main component in the cells of any living being we know of. Cells are constantly moving ions in and out in order to keep their concentration right and for many other reasons. Osmosis pulls water into cells when the salt concentration within the cell is higher than outside, puffing up the cell to an ideal size.

While NaCl is best known for its use in food, its main use by weight is for de-icing roads, at least in the USA[1] . Many tons of salt are used in the chemical industry, too. It’s used to make sodium hydroxide (lye), glass, soda ash, and so on. It’s used in processing of many materials such as metals, paper and rubber. And apparently, it’s also used in fire extinguishers designed to put out combustible metal fires.

Feasibility of the reaction
Feasibility: High.
If you don’t know how to move a spoonful of salt around, I’m afraid you’re beyond my help. By the way, there’s about a few tens of thousands grains of salt in a teaspoon. That’s about 110 000 000 000 000 000 000 000 ions of chlorine and an equal amount of ions of sodium.


3: Sun simulator
Inputs: Hydrogen
Outputs: Helium, Hydrogen

I talked about this molecule during round 6.

Helium, He
Melting point: None at standard pressure.
Boiling point: -269 °C, -452 °F
Molecular mass: 4.00 u
Density: 0.17 g/L

Helium is an interesting little element. It’s named after the sun, Helios, where it was first detected as an unknown line in the sun’s spectrum. While it’s the most common element in the universe after hydrogen, it’s rather rare on earth. As a noble gas, it won’t form compounds (unless you force it to, and even then it forms rather unstable thingies), and its density is so low that it can escape earth’s gravity. The helium we use comes from underground gas fields, and the largest resource of helium we know of is located below the United States. Most earth helium was formed by natural radioactivity over a period of billions of years. The alpha particles sent out by many radioactive elements are actually helium nuclei.

Helium is best known for its use in balloons and blimps, and for inhaling it to get a high voice. But those uses are kind of a waste if you ask me. An important use in science and medicine is for cryogenic cooling. Cooling with helium is what makes supermagnets work, and these supermagnets are used in NMR (a chemical analysis technique), particle smashers such as the Large Hadron Collider in Geneva, and also in medical MRI scanners. Helium is also used in certain controlled atmosphere applications.

The big problem is that helium is a limited resource on earth. With the current use, we may well run out within this century. That’s going to cause big problems in science and medicine. This is kind of similar to the fossil fuel problem, however for fossil fuels we can find replacements, like biodiesel. There is nothing that can replace helium. We can technically make more with nuclear reactions, but that’s a lot of work for a tiny, tiny amount. When our helium is gone, it's gone for good. The only option may be to go mine for the stuff in space. I honestly don’t understand why such an important, limited resource is still so cheap. Think about that for a moment whenever you plan to buy a helium balloon.[2]

Helium has very interesting properties at low temperature. For starters, it’s the only element, heck, as far as I know the only substance, that just refuses to get solid, even if you cool it down to absolute zero. You can get it solid, by cooling it down to near absolute zero at a pressure of about 25 atmospheres. It’s difficult to get helium solid because of a quantum property called ‘zero point energy’. It means that atoms, even at the lowest possible temperature, still appear to vibrate a bit. They still have energy, and there is no possible way to get that out of them. The bonds between helium atoms are so weak that the zero point energy is enough to keep the stuff liquid at normal pressure.

Helium becomes a liquid at 4K (0K is absolute zero). At that point it’s known as Helium I, and it behaves relatively normally. A strange property is that it has a much lower density than predicted by classical physics. At such low temperatures, atomic quantum mechanical effects become more important than the regular (electron) effects of heat. This also means that the helium-3 isotope behaves rather differently than the more common helium-4 form.
Below 2K, the helium-4 isotope undergoes another change, into a state known as Helium II. In this state, helium is a superfluid, another state of matter governed on a macroscopic scale by quantum mechanics. All sense of normalcy goes out of the window at this point. A superfluid has zero viscosity. If you put it in an open cup, it will flow up against the edges and out of the cup until the cup is empty. Helium II has the highest heat conductivity of any known substance. It is so high that Helium II heated above the boiling point won’t form bubbles, it will just evaporate. Most materials transfer heat by electron effects, but Helium II uses some kind of quantum wave, which apparently is in some ways similar to sound. This effect is known as ‘Second sound’. Strange stuff.

Feasibility of the reaction
Feasibility: High.
This is most probably the only nuclear reaction in this tournament that I’ll give a high feasibility. That’s because it’s already being done, in a sense. Wild M already linked to the Proton-proton chain reaction, which is what happens in the sun. Note that the complete reaction formula for that one is 61H -> 14He + 21H (+ energy, some positrons and some neutrinos). The superscript numbers are the atomic mass numbers, as isotopes are important in nuclear reactions. The ‘extra’ hydrogens are turned into neutrons in the helium nucleus, which makes the actual reaction different from the SpaceChem one. I didn’t type H2, because the solar plasma is so hot that there aren’t any molecules, just loose nuclei and electrons.

Hydrogen bombs and nuclear fusion reactors use a similar process, but creating helium from regular 1H isn’t very practical in controlled conditions. They often use heavy hydrogen isotopes, with the reaction 2H + 3H -> 4He + neutron, instead.

Reaction energy: Exothermic, about 2 570 000 000 kJ/mol (for proton-proton chain reaction); 1 700 000 000 kJ/mol (for the reaction with the heavier isotopes).
I told you nuclear reactions are powerful. You won’t find any chemical reaction with this kind of energy output. The problem with fusion energy is that it also has a huge energy barrier it needs to overcome before it starts going. It’s also not a self-sustaining chain reaction like nuclear fission. It’s gonna be a while before we can use fusion reactors (not counting the sun) as a daily energy source.


Challenge 1: Misfortune Modifier - Input Island
See Misfortune Modifier.