Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Hydrochloric acid (HCl) reacts with sodium carbonate (Na2CO3), forming sodium ch

ID: 522601 • Letter: H

Question

Hydrochloric acid (HCl) reacts with sodium carbonate (Na2CO3), forming sodium chloride (NaCl), water (H2O), and carbon dioxide (CO2). This equation is balanced as written: 2HCl(aq)+Na2CO3(aq)2NaCl(aq)+H2O(l)+CO2(g) Part A What volume of 2.50 M HCl in liters is needed to react completely (with nothing left over) with 0.750 L of 0.500 M Na2CO3? Express your answer to three significant figures and include the appropriate units. Part B A 651-mL sample of unknown HCl solution reacts completely with Na2CO3 to form 12.1 g CO2. What was the concentration of the HCl solution? Express your answer to three significant figures and include the appropriate units.

Explanation / Answer

2HCl(aq)+Na2CO3(aq)2NaCl(aq)+H2O(l)+CO2(g)

Part A: We can simply proceed by equating the moles of reactants on the two sides of the equation.

Let volume of HCl needed be x L.

Then,

Moles of Na2Co3=Moles of HCl

0.500M * 0.750 L = 2 * 2.50M * x L

On solving, x=0.075 L

Part B.

In this part, like in part A, we equate the moles on the two sides of the equation,

Let the concentration of HCl be xM.

Moles of HCl= Moles of Na2Co3

12.1g / 44 g/Mol= 2 * 0.651 L * x M

On solving, x= 0.037M