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)

A 327-mL sample of unknown HCl solution reacts completely with Na2CO3 to form 18.1 g CO2. What was the concentration of the HCl solution?

Answer 1

Given balanced equation is:

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

From the balanced chemical equation we get the information that :

2 moles of HCl reacts with -----------1 mole of Na2CO3 and forms ---44g of CO2

Means 2moles of HCl is giving------------ 44g of CO2

? moles of HCl -----------------------------------gives 18.1g of CO2

= (18.1 * 2)/44

= 0.823 moles of HCl

Concentration of 0.823moles of HCl in 327 ml of sample (molarity) = 0.823/0.327

(Since molarity= no.of moles /volume in litres)                                            = 2.52M