Table 2.

Thermodynamic data for the reaction in standard cells of the saturated cadmium sulfate type at 25 °C − based on experimental enthalpies for reactions (a), (b), (c), and (d) and experimental Gibbs energy for reaction (d)

Reaction	Gibbs energy change	Enthalpy change	Entropy change	Heat‒ capacity change
	ΔG J mol‒1	Δ H J mol‒1	ΔS J K1 mol‒1	ΔCp J K‒1 mol‒1
(a)	#(‒196,745) (‒8,824) (‒1,171) 770	‒189,983 ‒20,426 ‒13,372 937	22.68 ‒38.91 ‒40.92 (0.544)	ϕ‒2.402 ‒40.350 ‒46.765 ‒4.180
(b)
(c)
(d)
sum 1 (e)*	‒205,970 9,743	‒222,844 23,764	‒56.606 47.03	‒93.722 0
sum 2p (e)**	‒196,227 9,738	‒199,080 21,240	‒9.576 38.58	‒93.722 204.26
sum 3q	‒196,232	‒201,604	‒18.026	110.538
	(cal mol‒1)j	cal mol‒1	cal K‒1 mol‒1	cal K‒1 mol‒1
(a)	(‒47,023) (‒2,109) ‒280 184	‒45,407 ‒4,882 ‒3,196 224	5.42 ‒9.30 ‒9.78 (0.13)	ϕ‒0.580 ‒9.644 ‒11.177 ‒0.999
(b)
(c)
(d)
sum 1 (e)*.	‒49,228 2,328.6	‒53,261 5,679.8	‒13.53 11.24	‒22.400 0
sum 2p (e)**	‒46,899.4 2,327.5	‒47,581.2 5.076.4	‒2.29 9.22	‒22.400 48.82
sum 3q	‒46,900.5	‒48,184.6	‒4.31	26.420

^#Values in parentheses were calculated from the relation ΔG = ΔH − TΔS.

^ϕSee text for alternate value of − 2.799 J K⁻¹ mol⁻¹ or − 0.669 cal K⁻¹ mol⁻¹.

^*Based on data of Hulett [34] and Getman [35].

^pSum 1 + (e)*.

^**Based on data of Parks and LaMer [39].

^qSum 1 + (e)^**.

^j1 Thermochemical calorie (defined) = 4.184 J [1].