what acid does it form when cardon dioxide dissolve in blood

when cardon dioxide get into blood stream,
it would be binded by haemoglobin and form carboxyhaemoglobin.
it is a part of buffer system in blood so that CO2 can not affect the blood pH
pH value of blood should be kept around 7.35-7.45

大錯特錯！！
Corboxyhaemoglobin 係 Carbon monoxide 造成，Carbon Dioxide 係以 Carbonate 形式在 Plasma 中運輸，太多 Carbonate 會令血變酸，死人的！

carbonic acid?
when carbon dioxide dissolve in water, it will form carbonic acid (碳酸). I think it is similar when dissolve in blood.
It is weak acid.