PENGARUH ION Cu(II) DAN Fe(III) TERHADAP EFEKTIVITAS REDUKSI ION [AuCl4]- OLEH SINAR UV DAN ASAM OKSALAT
| Main Authors: | , NURHAYATI, , Prof.Dr. Endang Tri Wahyuni, M.S |
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| Format: | Thesis NonPeerReviewed |
| Terbitan: |
[Yogyakarta] : Universitas Gadjah Mada
, 2014
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| Subjects: | |
| Online Access: |
https://repository.ugm.ac.id/133375/ http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=74011 |
Daftar Isi:
- The influences of Cu(II) and Fe(III) ions with variation of the concentration and pH on the reduction of [AuCl4]- ion by UV light and oxalic acid have been studied. The reduction process was carried out by irradiating a mixture of 0,25 mmol/L [AuCl4]- ion solution, 0,50 and 0,25 mmol/L oxalic acid, with or without Cu(II) and Fe(III) ions with variation of the concentration and pH in a closed reactor equipped with UV lamp for 24 hours. The effectiveness of the reduced [AuCl4]- ion in the solution was calculated by subtracting the initial [AuCl4]- concentration by the unreduced concentration after the reduction process. The unreduced [AuCl4]- ion concentration was determined by Atomic Absorption Spectrophotometric method (AAS). The results of the research showed that the presence of oxalic acid and Cu (II) ion gave no effect on the effectiveness of [AuCl4]- ion reduction because the competition on the reduction of Cu(II) ion was very low. On the other hand, the Fe(III) ion could improve the effectiveness of [AuCl4]- ion reduction with the increasing amount of Fe(III) ion because of the synergy effect. pH gave significant effect on [AuCl4]- ion reduction either with or without the presence of Cu(II) and Fe(III) ions. The highest effect on reduction of [AuCl4]- ion by UV light and oxalic acid, Cu(II) and Fe(III) ions could be achieved at pH 3, which was related to the speciation of Au(III) ion, oxalic acid, Cu(II) and Fe(III) ions. The XRD data showed that the solid resulted from [AuCl4]- ion reduction by UV light and oxalic acid in the presence of Cu(II) and Fe(III) ions was gold metal.