A piece of limestone to 1dm³ of 0.1mol/dm³ of HCl. After effervescent had stopped, 31.25cm³ of the resulting solution required 25cm³of 0.05mol/dm³ of NaOH for complete neutralization. Take ( Ca=40, Cl=35.5, O=16, H=1, Na=23, C=12).
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