Sintesis dan karakterisasi senyawa pirazolin [2,2'-(4,5-dihydro-1H-Pyrazole-3,5-diyl) diphenol] dari senyawa chalcone menggunakan katalis Na terimpregnasi cangkang telur ayam teraktivasi (Na-ACE) = Synthesis and characterization of pyrazolin [2,2 '- (4,5-dihydro-1H-Pyrazole-3,5-diyl) diphenol] from chalcone compounds using activated chicken eggshell impregnted (Na-ACE)