Formic acid has a pKa value of 3.75. The pKa value is derived from the acid dissociation constant, Ka, for formic acid, which is .00018. The pKa value can be found by taking the negative log of the Ka, which is -log(.00018).
Formic acid is a weak acid with the formula HCOOH that can be produced through artificial lab synthesis. Additionally, it is a common component of ant venom. Formic acid has a molar mass of 46.03 grams per mole. It can be derived through a reaction between methanol and carbon monoxide, or through the reaction of hydrolizing methyl formate. It is also a byproduct from the production of acetic acid.