What acid in the car battery? Question to chemists
Several times I asked this question in letters to the blog, many beginner drivers are interested, who only comprehend driving issues. Many have heard of acid-lead batteries, but they do not represent how they work and why in principle inside the acid. Others know that it is there, but that's what you do not represent! Third generally believe that inside only distilled water and no acid there! Today I still decided to answer all these questions. It will be interesting, so read on ...
Immediately I want to answer such a question - the acid is still in the car battery there, and one of the most powerful, namely, is "sulfur" acid, if we recall the formula from H2SO4 chemistry. So all the conversations that water is filled with alone, to put it mildly unjudigious. After all, therefore, the name is the name of acid-lead batteries.
For what it applies
Sulfuric acid is one of the components of the battery, without it, there would be no charge and battery discharge. This is one of the most active inorganic acids, interacts with almost all metals and their oxides, also enters into the exchange reaction. Activity depends on the presence of water in it.
However, it is not absolutely clean, but diluted. The ratio is approximately: 70% water and 30% sulfuric acid, it is the so-called "electrolyte". It is such a composition that will effectively interact with lead plates.
Lead highlights electrons that lead oxide takes (plus and minus plates), and when discharge, on the contrary, sulfuric acid is actively helped by this transmission. Do not be in structure the effectiveness of the battery, would fall at times.
I would like to say that lead-acid batteries, there are still from the mid-19th century and for such a long "path" to our time, they have little to change. Look at this informative video.
In fairness it is worth noting - that the electrolyte can be almost any liquid medium, even ordinary water (there is, of course exceptions, but there are not so many).
Battery electrolyte
As we understood from above, it is a kind of mixture of various liquids. Other liquid media can be electrolyte, and recently gels. A simple experiment - take a jar with water and shove into it, two nails are one copper, another aluminum. Connect the multimeter to them, and you will see - that they produce an electric current, let it be negligible, but still it will be there, this is the effect of "batteries". The current will be produced until one of the metals decompose, as a rule, having the smallest resistance. However, the principle of the battery is a bit different.
Present two plates, lead and its oxide. When charging, as I wrote above - lead begins to give its electrons with oxide, that is, as if "collapses." But when discharge, they return from "oxide" back - recovery occurs. That is why the battery is a multi-rechargeable battery. For active interaction - destruction - plates restoration, need an aggressive environment promoting the exchange, it is for this that serves sulfuric acid They are practically ideal for such work. But it is impossible clean it is impossible, it is so active that he will simply destroy lead, perhaps it is soluble. Therefore, it is diluted with water in a certain proportion, so it turns out a car electrolyte of a certain density.
A little about density
The last thing I want to note is that the concentration of acid can affect the density of the electrolyte, the concentrated has an indicator of 1.83 g / cm3. If you add distilled water into it, the density decreases to the desired level.
Indicators of the finished electrolyte can vary from 1.2 to 1.4 g / cm3.
The density you need to know first in order to understand the threshold. For example, the density of 1.11 will freeze already with minus seven degrees. But, for example, the recommended 1.27 - 1.28, have a threshold in -58, -64 degrees. Small signs for understanding.
I will finish this, I think I answered you all your questions, tried to tell the maximum simply. Read our automotive, there will be a lot of interesting things.
