[Borek]

What is the difference between hydrochloric acid and muriatic acid?

You were already told that. Are you reading the answers provided, or do you just ask again and again?

[AWK]

What is the difference between hydrochloric acid and muriatic acid?

see Etymology in https://wiki2.org/en/Hydrochloric_acid

[yoshiisland]

Muriatic Acid evaporates when it is used, after it evaporates it falls on the electronic circuit board what will happen when I turn on the device? Will the steam on the board evaporate again?

[Borek]

Muriatic Acid evaporates when it is used, after it evaporates it falls on the electronic circuit board what will happen when I turn on the device? Will the steam on the board evaporate again?

Yes and no. HCl molecules will not just get adsorbed on the surface (those just adsorbed will be generally capable of leaving later, but these are very small minority). Most of the HCl molecules will directly react with whatever they sit on and corrode it. Some of the reaction products can decompose on heating, producing HCl back, some will not.

[yoshiisland]

Is the steam generated by the use of muriatic acid enough to stick to the circuit board and never come out gradually eroding the metals? Even in use with a heated appliance, is the steam on the circuit board?

electronic board has metails

[Corribus]

I'm not sure what you expect from us. Yes, HCl corrodes metals. Yes, HCl will probably corrode circuit boards. Yes HCl is volatile and yes the fumes are also corrosive. No, you shouldn't use HCl in a poorly ventilated space because it could damage your electronic equipment over time, or your lungs. That said, Yes, we do use HCl in chemistry labs, and Yes we often have computers and electronic equipment in labs. But labs are also designed with good ventilation. So No, it's not necessarily a comparable situation.

You are asking for a yes or no answer to a question that depends on a lot of factors, including how much HCl you are using, the concentration, the frequency, the amount and type of circuitry boards you have and where they're stored, and the air-movement characteristics of the space you're working in. Impossible to answer your question in a black or white way probably even if we knew all these details.

Is the risk to your boards in the short term high? Probably not. But if you don't want your circuit boards degraded, or some kind of chronic long disease, don't use HCl inside your home in an unventilated space. That's the only way to be sure and I'm not sure what else any of us can add.

[yoshiisland]

How do I find out if it is well ventilated? my room has appliances but it has no window

[Corribus]

As mentioned before, that's not well-ventilated from a chemical handling perspective. Chemical labs are designed to have short air cycling times because there are fume hoods. Even if you're not actually working in a fume hood, because fume hoods are constantly drawing air from the room, the air is continually cycled and replaced by clean outside air. In your house, air is primarily moved by diffusion/Brownian motion and your HVAC system if it is turned on. So while air does cycle, it's much slower than in a professional laboratory. Particularly when there are barriers that slow the diffusion of air (e.g., walls with no windows).

Anyway, that's neither here nor there. Point is, it's impossible to know what is "good enough" ventilation because as mentioned above there are too many factors involved, not the least of which is "how much corrosion is acceptable". Sorry, your question just doesn't have a definitive answer, particularly without hard data on air replacement cycles, where equipment is located, and so forth.

As with most things: if you don't want any risk, don't do the risky behavior. If you must do the risky behavior, mitigate it the best you can but be prepared to live with the consequences.

[Borek]

And with these two great answers from Corribus I am locking the thread, as it has definitely run its course.