b0 0 k reviews Apparently misled by the fact that one expression for the difference C, - Cv ineludes (bVIbT), asafactor, the author states that this difference is negative when the coefficient of expansion isnegative, as for water between 0 and 4 "C.A few seconds' consideraum of onvthar standard furmula for this difierencr. T\ir2 .l, would have shown that the sign ot' C, - ( ' v is indepcw dent of that of a and is never negative. One of the exercises asks the student t o prove that for an isothermal change in an ideal gas AG = -AA. The student who finally givesup the struggle to prove this erroneous relation and turns t o the answer page finds it "proved" there by an easily noticed sign error. Another exercise calls for deriving expressions for C, and C, in terms of T, V , a, and the isothermal and adiabatic compressihilities (3r and Us; the expressions as eiven are interchaneed. .. . and moreover the rompreseib~litiriarc incorrectly dctinrd. The altsucr 11, anuthrr rxrrclse givrs the wlue uf (op, dl',.$ fur an ideal gas as ~p 1'. The mi rain^ minussign mas hconlg a mmor s i p I t it s u g ~ r $ t sthat thr 311thmhac not dune somethmr that e v m teacher
