HYDROGES-IOS COSCESTRA TIGS' 



151 



calculated c<Hic«itrati<Mis of hydrogen and hydroxyi ions in sohition; <rf 

 hydrochloric acid and potasdum hydroxide are given in Tat4e 30. C<«n- 

 plete ionization was assumed in these falmlatioPiS. 



Table 30. Calcxxated Coxcest^atioks or Htoso^cix axd Htdeoiti. loss rs 

 Prsz Watee axd cf SoLmoxs of Htdeoceuckic Acid axd PotasctctiC 



S<$rensen devised a logariiiunic ~ ^ - ~-^: 

 hydrc^en icHis in solutions. The ij^:.. _ . - . 

 tial of hydrogen.'" which is abreviated to pH. 

 and hydrc^en-ion concentration is grven bdow. 



- -V:.c -^1= ;c 



in-e "I r.i-- 

 i^nseei pH 



5) 



pH=logi 



•^H="] 



In words this equation means pH is equal t : _ - . ' of 



the reciprocal (rf the hydrogaMon : r. r _ : :_ x^wk oO li £ 



seen that the hydrogen-itm ctMicentrtiiioii ci •j.l,'^»juu'UV z.ydrorhloric add 

 is 1 X 10~* mole per liter. Suhstitutiiiz "his value in Eq. ^5), "we hxve 



(6) 



1 .X. l\f~* 



-. = lie 10* = 6 



One obvious advantage <rf the pH scale lies in the fact that hydrogen-ion 

 concentrations are expressed as positive numbers rather than as decimal 



