brrpa mo 3,7 gram ca(oh)2 bila ar ca = 40 O= 16 dan h = 1

Mr = ar ca + 2 ar o + 2 ar h
Mr = 40 + 2(16)+2(1)
Mr = 40+32+2 = 74

mol = massa / Mr
mol= 3,7 / 74
mol = 0,05 mol

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