Heat Capacities, Absolute Entropies, and Entropies of Formation of Amino Acids and Related Compounds

Heat capacity https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315314440/e2f9a2bb-7701-4891-988b-084507d1705c/content/ch4_equ_0001.tif"/> ( C p ° ) , absolute entropy (S°), and the entropy change for formation from the elements (ΔSf°) are given for a temperature of 298.15 K. The units are cal deg^–1 mole^–1 for all entries except for proteins where they are cal deg^–1 g^–1. 1 cal = 4.1840 absolute joules and 0°C—273.15 K. International Atomic Weights of 1959 are employed. In calculating ΔSf° the entropies of the elements used are (in cal deg^–1 mole^–1) C (graphite), 1.3609; H₂ (gas), 31.211; O₂ (gas), 49.003; N₂ (gas), 45.767; Cl₂ (gas), 53.31; and S (rhombic), 7.62.¹ S° for D₂ (gas) is 34.620 cal deg^–1 mole^–1.²