In May 2019, certain fundamental constants that had been measured in SI units have had their numerical values fixed, with no uncertainty, thus defining the units. Of importance to electroanalytical chemistry are the values of the Boltzmann constant, the elementary charge, and the Avogadro constant. These are given in the table below, with calculated values of the Faraday constant (\(F = e·N_{\rm{A}}\)) and gas constant (\(R = k·N_{\rm{A}}\)).

Table 1 Values of constants of importance to electrochemistry in the SI after 20 May 2019.

Constant	Symbol	Numerical value	Unit
elementary charge	\(e\)	\(\pu{1.602176634E-19}\)	\(\pu{C}\)
Boltzmann constant	\(k\)	\(\pu{1.380649E23}\)	\(\pu{J K-1}\)
Avogadro constant	\(N_{\rm{A}}\)	\(\pu{6.02214076E23}\)	\(\pu{mol-1}\)
Faraday constant	\(F\)	\(\pu{9.64853321E4}\)	\(\pu{C mol-1}\)
molar gas constant	\(R\)	\(\pu{8.31446262}\)	\(\pu{J K-1 mol-1}\)