Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The ...Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K 2CO 3·3/2H 2O,Li 2 B 4O 7·3H 2O, K 2 B 4O 7 ·4H 2O and Li 2CO 3. The composition of the solution corresponding to E was w(CO 2- 3)=2.27 %, w(B 4O 2- 7) =6.05 %, w(K + ) =4.30%,w(Li + )=0.30 % and the equilibrium solids were Li 2 B 4O 7· 3H 2O+K 2 B 4O 7·4H 2O+Li 2CO 3;The composition of the solution for F was w(CO 2- 3) =22.45%,w(B 4O 2- 7)=1.88%,w(K + )=29.96%,w(Li + )=0.03% and the equilibrium solids were K 2CO 3·3/2H 2O+ K 2 B 4O 7·4H 2O+Li 2CO 3. K 2CO 3 possesses strong salting-out effect on K 2 B 4O 7,Li 2CO 3 and Li 2 B 4O 7.展开更多
In the dilute H2SO4medium of c (H2SO4)0.090.16mol·L-1,trace amount of Cr2O2-7reacts with protonated 3.5-diCl-PADAP to form an ion-association complex having its maximum absorption at 553nm and a molar absorptivit...In the dilute H2SO4medium of c (H2SO4)0.090.16mol·L-1,trace amount of Cr2O2-7reacts with protonated 3.5-diCl-PADAP to form an ion-association complex having its maximum absorption at 553nm and a molar absorptivity of 4.51×104L·mol-1·cm-1.Beer’s law is obeyed in the range of 03.3μg.mL-1for Cr2O2-7.The method presented has been used in the determination of Cr2O2-7in water and tea.The recoveries obtained were in the range of 97.6%100%.展开更多
文摘Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K 2CO 3·3/2H 2O,Li 2 B 4O 7·3H 2O, K 2 B 4O 7 ·4H 2O and Li 2CO 3. The composition of the solution corresponding to E was w(CO 2- 3)=2.27 %, w(B 4O 2- 7) =6.05 %, w(K + ) =4.30%,w(Li + )=0.30 % and the equilibrium solids were Li 2 B 4O 7· 3H 2O+K 2 B 4O 7·4H 2O+Li 2CO 3;The composition of the solution for F was w(CO 2- 3) =22.45%,w(B 4O 2- 7)=1.88%,w(K + )=29.96%,w(Li + )=0.03% and the equilibrium solids were K 2CO 3·3/2H 2O+ K 2 B 4O 7·4H 2O+Li 2CO 3. K 2CO 3 possesses strong salting-out effect on K 2 B 4O 7,Li 2CO 3 and Li 2 B 4O 7.
文摘In the dilute H2SO4medium of c (H2SO4)0.090.16mol·L-1,trace amount of Cr2O2-7reacts with protonated 3.5-diCl-PADAP to form an ion-association complex having its maximum absorption at 553nm and a molar absorptivity of 4.51×104L·mol-1·cm-1.Beer’s law is obeyed in the range of 03.3μg.mL-1for Cr2O2-7.The method presented has been used in the determination of Cr2O2-7in water and tea.The recoveries obtained were in the range of 97.6%100%.
