Carbonic acid (H2CO3) is a weak diprotic acid withKa1=4.43×10−7 and Ka2=4.73×10−11. When sodiumbicarbonate (NaHCO3) is titrated with hydrochloric acid (HCl), itacts as a weak base according to the equation
NaHCO3(aq)+HCl(aq)→H2CO3(aq)+NaCl(aq)
Part A
What volume of 0.190 M HCl is required for the completeneutralization of 1.70 g of NaHCO3 (sodium bicarbonate)?
Express your answer to three significant figures and include theappropriate units.
Part B
What volume of 0.120 M HCl is required for the completeneutralization of 1.80 g of Na2CO3 (sodium carbonate)?
Express your answer to three significant figures and include theappropriate units.
Part C
A sample of NaOH (sodium hydroxide) contains a small amount ofNa2CO3 (sodium carbonate). For titration to the phenolphthaleinendpoint, 0.170 g of this sample requires 23.98 mL of 0.100M HCl. An additional 0.700 mL of 0.100 M HCl isrequired to reach the methyl orange endpoint. What is thepercentage of Na2CO3 by mass in the sample?
Express your answer to three significant figures and include theappropriate units.
