PENGGUNAAN MODEL CONCEPT SENTENCE DALAM PEMBELAJARAN MENULIS PARAGRAF

The objectives of these research was to developed student’s competence of writing a paragraph in using Concept sentence. These Classroom action research held at the 3rd grade of SDN 20 West Halmahera at the year of 2018-2019. The type of this research was classroom action research and consist of two cycles that includes in planning, action, observation and reflection. The technique that used in this research were, observation, interviews and evaluation. The result of this researched concluded that in using concept sentence increased students competence in writing a paragraph proved by some items consisted of (1) concept sentence correctly implemented (2) the setting or placement of the punctuation and letter were correctly (3) the students chosen of words in thir thought based on the key words (4) the interrelation of each sentence in a paragraph was correctly design.Key Words: Improving, concept sentence model, writing paragraph

Thermodynamics of substituted pyrazolone. V: Potentiometric and conductometric studies of complexes of some transition metals with 4-(4-acetophenyl)hydrazono-3-methyl-2-pyrazolin-5-one

Proton-ligand dissociation constants of 4-(4-acetophenyl)hydrazono-3-methyl-2-pyrazolin-5-one (AHMP) and metal-ligand stability constants of its complexes with some transition metal ions were calculated potentiometrically in 0.1 M KCl and 50% (v/v) ethanol-water mixture. The order of stability constants was found to be Th4+ > UO22+ > Ce3+ > La3+ > Mn2+ < Co2+ < Ni2+ < Cu2+ > Zn2+. The dissociation constant, pK1H, of AHMP and the stability constants, log K, of their complexes were determined at different temperatures (298, 308, and 318 K). The corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) were derived and discussed. The dissociation process is nonspontaneous, endothermic, and entropically unfavourable. The formation of the metal complexes has been found to be spontaneous, exothermic, or endothermic (depending the metal), and entropically favourable. The stoichiometries of these complexes were determined conductometrically and indicated the formation of 1:1 and 1:2 (metal:ligand) complexes. Key words: 4-(4-acetophenyl)hydrazono-3-methyl-2-pyrazolin-5-one, dissociation and stability constants, thermodynamic parameters, stoichiometries.