Summary Pearson (Edexcel) A-Level Chemistry Chemical Reference Data Standard Formation Enthalpies Table Overview

Substance State (at 25˚C) Type
HNO3 l -174.1 Covalent
HNO3 aq -207.4 Covalent
HF g -271.1 Covalent
HCl g -92.3 Covalent
HCl aq -167.2 Covalent
HBr g -36.4 Covalent
HI g 26.5 Covalent Trend: ∆Hf increases down Group 7
H2O l -285.8 Covalent
H2O2 l -187.8 Covalent
H2S g -20.6 Covalent
H2SO4 l -814 Covalent
H2SO4 aq -909.3 Covalent
C (diamond) s 1.9 Covalent (giant)
CH4 g -74.8 Covalent
CH3OH l -238.7 Covalent Trend: ∆Hf decreases (alkane > alcohol)
C2H2 g 226.7 Covalent
C2H4 g 52.3 Covalent
C2H6 g -84.7 Covalent
CH3CHO l -192.3 Covalent
CH3COCH3 l -248.1 Covalent
C2H5OH l -277.7 Covalent
CH3COOH l -484.5 Covalent Trend: ∆Hf decreases (alkyne > alkene > alkane > aldehyde > ketone > alcohol > carboxylic acid)
C3H8 g -103.9 Covalent
C4H10 g -126.2 Covalent
CH3COOC2H5 l -479 Covalent Trend: ∆Hf decreases (alkane > ester)
C6H6 l 49 Covalent
C6H12O6 s -1274 Covalent Trend: ∆Hf decreases (arene > aldehyde + alcohol*)
C6H5CH3 l 12.1 Covalent
C8H18 l -249.9 Covalent