The answer is, 1 Drop. p.629 Refrigeration & Air Conditioning Technology 5th Edition
How much refrigerant used to recharge the AC system in a Honda Civic depends on how much the system needs. There will be a gauge on the refill bottle which is tell the user how much is needed in that one application.
about 10% to 15% of system charge
How much it takes, or how much it has in the system at any given time? To know how much refrigerant goes into the system, there'll be a sticker from the manufacturer - usually on the section of the HVAC compartment which extends under the hood. If this is faded or absent, the owner's manual should tell you. If that's unavailable, there are online resources. As for what's in your system at the moment, the only way to tell is to evacuate, recover, and weigh the refrigerant you have in your system.
Yes you can have too much refrigerant in your A/C system and it will damage the system. The only way to know how much is in the system is to measure it by using a gauge.
about 10% to 15% of system charge
about 10% to 15% of system charge
liquid
About 10 degrees
I have put refrigerant in my 2002 Sonata. May sure you get the gauge that tells you how much refrigerant is already in you A/C because if you overfill it, the A/C compressor will stop working. Then you will have to have the system bled to remove the excess refrigerant and that stuff is toxic and will burn your skin and put a bigger hole in the ozone layer. Better to underfill then overfill. The system is pressurized and will not work when there is too much pressure in it.
about 10% to 15% of system charge
For starters, you'll get insufficient cooling from your system. Refrigerant changes states from liquid to vapor and back again in order to achieve cooling, and the system pressure is balanced to facilitate this - excessive refrigerant makes it much more difficult to do this. Additionally, your system will generate excessively high pressure, which will ultimately damage or destroy system components.
There should be a sticker under the hood which tells which refrigerant is used and how much for that particular system.