Chapter 1173

"One more thing, Shen heard that Brother Xian mentioned that you want to find green alum oil, I don't know what you are doing with that thing? Although that thing is commonly used by the Taoist Fang family in alchemy, it doesn't seem to be of much use other than that. ”

Wang Yang explained with a smile: "The younger brother has just fired a new ingredient, so I want to get some alum oil to do some experiments." ”

"What about experiments?" Shen Kuo smashed his mouth and couldn't help laughing. "That thing is quite dangerous, it can't be stored in ordinary things, it must be held in porcelain, and it needs to be kept secret......"

"Could it be that Brother Shen has also studied this thing in the past?" Wang Yang couldn't help but be interested, and asked curiously.

Shen Kuo smiled, nodded and began to explain. "Well, it's just a little bit of a problem, if this alum oil is stored for a long time and is not well sealed, it is easy to increase the weight, and its effectiveness will be greatly reduced......"

"This problem is actually very simple, because alum oil has strong hygroscopicity, and the moisture in the air is inhaled by it, more water, the weight of alum oil will naturally increase, and once there is more water, then the effect of alum oil will naturally weaken." After Wang Yang heard this, he immediately understood what was going on.

"Oh? I don't think that Brother Yi really has a lot of research on this alum oil, and it took Shen a lot of time to figure out this truth. Hearing this, Shen Kuo's eyes suddenly lit up.

"Actually, the younger brother wants to try to use a certain concentration of alum oil to prevent iron rust." Wang Yang finally gave his own answer.

Nowadays, there are more and more metal parts, and how to prevent rust has become a nerve-wracking problem. Wang Yang came up with an excellent rust inhibitor or passivator: concentrated sulfuric acid.

"What?" Shen Kuo looked at Wang Yang in front of him with a strange expression, and it took a long time to inhale the airway like a toothache. "Brother Xian, I heard you right, right? The alum oil is very corrosive, and almost nothing is incorruptible except for gold. You actually said that thing could be used to prevent rust on iron? ”

"Hehe, it seems that Brother Shen, you don't know enough about this sulfur, uh-huh, alum oil. Alum oil can corrode metal and can also be used to remove rust from metal.

In addition, it has a very strange property, that is, when it reaches a certain sufficient concentration, it will not rust the metal, but will form an oxide film on the surface of the metal......"

"Oxide film, what the hell is that?" Shen Kuo, the best scientist in the Northern Song Dynasty, looked at Wang Yang with a confused face at the moment, as if he didn't quite understand what this product meant.

"Hmm...... It is a special substance, don't worry about this title first, so what is more intuitive than talking about it, it is better to do an experiment directly, and please Brother Shen come with me. ”

Wang Yang got up and led Shen Kuo towards his study, the metal can be passivated by pickling, which is described in the textbooks of later generations, when the metal is dissolved, under the passivation condition, a tight and well-covered solid substance is generated on the surface, and this substance forms an independent phase, which is called passivation film or phase film, also called oxide film.

In addition, if there is rust on the metal, it can also be pickled to remove rust, but rust removal is the opposite of the formation of an oxide film, and this reaction requires a concentration of 8% to 30% alum oil.

At room temperature, the solubility of sulfuric acid to metal oxides is weak, and the concentration is increased, so it is generally necessary to heat the sulfuric acid to a certain extent, and the efficiency can be improved by fifty or sixty degrees. However, when the temperature is too high, it is easy to over-corrode the steel matrix.

These things are all about sulfuric acid, that is, alum oil, in Wang Yang's fragmentary chemical knowledge.

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Soon, the two came to an independent room with closed doors and windows not far from Wang Yang's study, and Wang Yang explained to Shen Kuo when Wu Qilang opened the door with a key.

"This is my own chemical laboratory at present, and there are some alum oils that have been purified, and some of which are still low concentrations."

"Chemistry lab?" Shen Kuo couldn't help but smile bitterly. "Brother Xian, you open and close your mouth, full of new words that I can't understand."

"It's actually very simple, everything changes, and I divide these changes into two types, one is physical change, and the other is chemical change."

"The physical variation might be a bit better explained, when we polish a piece of crystal round and smooth enough, you throw it on a flat surface, and it rolls longer and for longer. If the surface of Shuichang is rough or even irregular, then it will not even be able to roll. ”

Shen Kuo patted his forehead. "It's like the wood, or the stone, if you don't treat it, you can't use it to build a house, or make all kinds of equipment, it's a physical change, isn't it?"

"It's worthy of Brother Shen, that's right, that's probably what it means." Wang Yang nodded and gave Shen Kuo a thumbs up.

"What about chemical changes?" Shen Kuo is worthy of being the best scientist of this era, his expression of eagerness for knowledge is like a child who longs for the truth, although his face is full of wrinkles, but his eyes are so thorough.

"Presumably, Brother Shen should also know that my Great Song Dynasty's gunpowder weapon, after being mixed with charcoal, nitrate, and sulfur, it will be ignited with fire, and a huge explosion will occur, which is a chemical change, also known as a chemical reaction."

"Like, you said that alum oil can remove rust when the concentration is low, and when the concentration is high, it can prevent rust, which is also a chemical change?" Shen Kuo's answer made Wang Yang really not know how to describe the IQ of this Shen University scientist except for giving a thumbs up.

It seems that this is an outstanding scientist who can lift the earth by giving him a fulcrum.

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After Wu Qilang and Wanyan Aguda carefully pushed open the door, Shen Kuo took a step in, and was directly stunned.

"These ...... So many crystal bottles and jars? I, I said Brother Xian, you are really ......" Shen Kuo looked at the colorless and transparent bottles and cans placed on the table in the room, and was directly stunned.

This kid is really too rich, right? I actually got so many crystal-made utensils, even if crystal is not a very worthwhile thing, but such a pure and transparent crystal is worth a lot of money.

"Actually, these are glasses fired from crystals. They have the same properties as crystals, which are resistant to high temperatures and corrosion. Brother Shen, you see, what is contained here is alum oil, and this bottle is a high-concentration alum oil that has been purified. ”

Wang Yang walked to the table and pointed to two glass bottles containing grease liquid and explained to Shen Kuo.

"The reason why we use this kind of crystal glass is because it is not afraid of corrosion and is resistant to high temperatures, just like porcelain, so it is the best vessel for chemical tests......