Vpliv kovinskih ionov na zvrsti citronske kisline v odvisnosti od pH

diplomsko delo

Sara Hodžič (Avtor), Bojan Kozlevčar (Mentor)

Povzetek

Pripravila sem raztopino citronske kisline (H4L) v vodi, ter vsakemu delu le- te dodala po eno izbrano zvrst kovinskih kloridov (NaCl, CaCl2, ZnCl2 ali CuCl2). Vsaki od teh raztopin sem nato dodajala raztopino NaOH do nevtralizacije raztopine. Vsem raztopinam je pH sorazmerno enakomerno naraščal do pH = 7. Bistvena razlika je bila pri Cu2+, kjer se je za nevtralizacijo porabila dvojna količina NaOH. Očitne razlike sem opazila pri merjenju prevodnosti, kjer je ob dodajanju močnega elektrolita NaOH prevodnost enakomerno naraščala le pri enovalentnih natrijevih ionih, pri ostalih (torej dvovalentnih) pa so vidna tudi izrazita upadanja prevodnosti. Takšne krivulje se skladajo s predvideno boljšo možnostjo vezave dvovalentnih kovinskih kationov na anion citronske kisline. Te pojave sem primerjala s tremi znanimi bakrovimi spojinami v tem sistemu [Cu2(L)(H2O)2]n, (CN3H6)4[Cu2(L)2](H2O)2 in (CN3H6)[Cu2(OH)(L) (CN3H5)2], katere sem sintetizirala po opisih v virih. Istovetnost teh trdnih spojin sem potrdila z elementno in praškovno rentgensko analizo, ter z IR ponovljivost sintez.

Ključne besede

citronska kislina;kovinski ioni;kovinski kloridi;pH;elementna analiza;rentgenska praškovna analiza;IR spektroskopija;diplomska dela;

Podatki

Jezik:	Slovenski jezik
Leto izida:	2019
Tipologija:	2.11 - Diplomsko delo
Organizacija:	UL FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik:	[S. Hodžič]
UDK:	547.477:546.3/.9(043.2)
COBISS:	1538435779
Št. ogledov:	761
Št. prenosov:	207
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Angleški jezik
Sekundarni naslov:	Metal ions influence on different citric acid species in relation to pH
Sekundarni povzetek:	A solution of citric acid (H4L) was prepared in water, to a portion of which one selected type of metal chlorides (NaCl, CaCl2, ZnCl2 or CuCl2) was added. To each of these solutions the NaOH solution was added until neutralized. The pH of all solutions rises steadily till pH =7, , with the most obvious difference for Cu2+, for which double amount of NaOH was needed for the neutralization. The most obvious differences were noticed at conductivity measurements, where with a strong electrolyte, namely NaOH was adding, the conductivity steadily rises only for the monovalent sodium ions. On other hand, with the other metal ions (notably divalent) clearly conductivity decreases are seen. These curves are consistent with the anticipated better ability of the divalent metal cations binding to the citric acid anion. These observations were compared to three of the known copper compounds in this system, namely [Cu2(L)(H2O)2]n, (CN3H6)4[Cu2(L)2](H2O)2 and (CN3H6)[Cu2(OH)(L)(CN3H5)2], being synthesized as previously described in resources. The identity of these compounds was confirmed by elemental and powder X-ray analysis, while the IR was applied for the synthesis reproducibility checking.
Sekundarne ključne besede:	citric acid;metal ions;pH;elemental analysis;X-ray powder analysis;IR spectroscopy;
Vrsta dela (COBISS):	Diplomsko delo/naloga
Študijski program:	1000370
Konec prepovedi (OpenAIRE):	1970-01-01
Komentar na gradivo:	Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo
Strani:	[55] str.
ID:	11226245