S2011:??Pre??lab??#6?? ?? Water??Hardness??Prelab?? ??N

S2011:??Pre??lab??#6?? ?? Water??Hardness??Prelab?? ??Name:?????? ?? ?? ?? ?? ?? ?? ????Section??(day??&??time):?????? ?? ?? ?? ?? 1.?? (5??points)??A??0.4505??g??sample??of??CaCO3??was??dissolved??in??HCl??to??dissolve??the??solid??and??the??resulting??solution?? was??diluted??to??250.0??mL??in??a??volumetric??flask.????A??25.00??mL??aliquot??of??the??Ca2+??solution??was??titrated??with?? 24.25??mL??of??an??EDTA??solution??to??the??Eriochrome??Black??end??point.???? a) What??is??the??concentration??(molarity)??of??Ca2+??in??the??250.0??mL??of??CaCl2??solution????? b) How??many??moles??of??Ca2+??are??contained??in??a??25.00??mL??sample????? c) How??many??moles??of??EDTA??are??contained??in??the??24.25??mL??used??for??the??titration????? d) What??is??the??concentration??(molarity)??of??the??EDTA??solution????? e) Based??on??your??answer??in??part??e??if??100.00??mL??of??a??water??sample??required??23.24??mL??of??EDTA??what??is??the?? hardness??of??the??water??in??terms??of??ppm??CaCO3??(ppm??=??mg/L)???
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