The crystalline compound ferric acid sulphate FeH(SO)(4). 4H(2)O (FHS) had its interlamellar gallery intercalated by a series of n-alkylmonoamines, H3C(CH2)(n)NH2 (n=1-7) from 1,2-dichloroethane (dce) and cyclohexane (cce) solutions. The intercalation was initially followed by a batchwise method at 298+/-1 K. The original interlamellar distance of 940 pm changed with the intercalated n-monoalkylamines, Thermogravimetric results showed that FHS lost H2O in the first stage, H2O plus SO3 in the second step, to leave Fe2O3 as the residue. The intercalated compounds lost amines in the second step. The interlamellar distance d depends on the length of the aliphatic n-alkylmonoamine and is correlated to the respective number of the carbon atoms n(c) in the aliphatic chain: d=(947.23+/-13.25)+(121.96+/-2.63)n(c). Linear correlations with good fits were obtained for the number of moles intercalated (n(int)) as a function of n(c): n(int)=(14.00+/-0.13)-(0.84+/-0.02)n(c) and n(int)=(11.15+/-0.13)-(0.57+/-0.02)n(c) in dce and cce, respectively. The enthalpic values Delta(int)H in kJ mol(-1), for the accomodation of the amines into the gallery were determined by reaction-solution calorimetry at 298.15+/-0.02 K. These values correlated with n(c), n(int) and d, by means of the equations: Delta(int)H=-(67.38+/-7.25)+(8.14+/-0.58)n(c); Delta(int)H=(47.18+/-5.26)-(9.68+/-1.02)n(int); Delta(int)H=-(133.35+/-15.12)+(0.07+/-0.01)d; and Delta(int)H=(40.92+/-7.45)-(8.48+/-1.05)n(int); Delta(int)H=-(53.75+/-9.87)+(6.02+/-1.78)n(c) and Delta(int)H=-(97.39+/-15.01)+(0.05+/-0.01)d for dce and cce, respectively. From these linear correlations the results suggest that enthalpic values can be inferred for other intercalated species.