A Concentration Problem in Chemistry

Calculating the Concentration of an Unknown HCl Solution

In a chemistry lab, a 547 mL sample of an unknown HCl solution was reacted with Na2CO3 to produce 17.1 grams of CO2. The balanced chemical equation for the reaction is:

2 HCl + Na2CO3 → CO2 + H2O + 2 NaCl

From the equation, we know that 2 moles of HCl react to form 1 mole of CO2.

Given that the mass of CO2 produced is 17.1 grams, we can calculate the number of moles of CO2:

number of moles of CO2 = mass / molar mass = 17.1 g / 44.01 g/mol = 0.388 moles

Since the ratio of HCl to CO2 is 2:1, the number of moles of HCl in the reaction is 0.388 moles x 2 = 0.776 moles.

Now, we can calculate the concentration of the HCl solution:

concentration = number of moles / volume in liters = 0.776 moles / 0.547 L = 1.42 M

Therefore, the concentration of the unknown HCl solution is 1.42 M.