Siti Nuryanti

Analisis Kadar Kalium (K) dan Posforus (P) Pada Limbah Kangkung Darat (Ipomea reptans Poir)

This research is aimed to determine potassium (K) and phosphorus (P) levels in the waste of swamp cabbage. The Spectrodirect instrument was used to analyze the levels of potassium and phosphorus in the waste of swamp cabbage. Based on analysis of the levels of potassium and phosphorus in the waste of swam cabbage, it was obtained that the average value of K concentration in the sample was 5.51213 mg/kg. On the other hand, the average value of P concentration in the sample was 43.19503 mg/kg. From the result of this analysis, it also demonstrated that the concentration of phosphorus was higher than the concentration of potassium.

Indikator Asam-Basa dari Bunga Dadap Merah (Erythrina Crista-galliL.)

Dadap red (erythrina crista-galli L.) is belonged to the legumes (fabaceaea) family which, is one of the flowering shade plants that often used as an ornamental plant. This plant has a bright red flower, a taproot with root nodule bacteria nitrogen fixation and compound leaf consists three strands on each stem. This research is climed to proves that the extract of dadap red flower can be used as acid-base indicators. Dadap red flowers was macerated using methanol then filtered. The filtrate was ready to use as an acid-base indicator. The extract is tested in an acid-base, buffer solutions, and was compared with phenolphthalein for a strong acid with a strong base while a methyl orange a weak base with a strong acid. Based on the result, indicator of dadap red flower extrat in the strong acid was red colour, while in the weak acid was pink, and also in the strong base was dark green and in the weak base was purple. Furthermore, in the buffer solution, the indicator of dadap red flower extract gave four groups of colour change, namely red color at pH 1 to pH 6, colorless at pH 7 to pH 9, brown at pH 10 and blue at pH 11 to pH 12. Additionally, to attain the end point of titration, the indicators of dadap red flower extract gives a similar results with the comparison indicators. The results showed that the indicator of dadap red flower extracts can be used as an alternative indicator.