1 normal acid or base (1N)

Biologists are sometimes confused by the non-standard[1] chemical unit of normality N. N refers in general to salts while it's most commonly used in the context of acid and bases.

• 1 M (mol/l) = 1 N for an acid that releases 1 proton* when dissolved in water, e.g. HCL (*monoprotic)
• 1 M (mol/l) = 2 N for an acid that releases 2 protons*, e.g. H₂SO₄ (*diprotic)

By the way, molarity M is also a non-standard unit[2]. Expressing this explicitly as mol/L or mol/m³ is clearer to readers less versed in current biological customs.

See also

• Normality section of Concentration page at the Wikipedia
• International standard units, SI units