In aqueous solution, hydrochloric acid, HCl, and sodium carbonate, Na2CO3 react to

produce gaseous carbon dioxide, CO2, water, H2O and sodium chloride, NaCl. A 10.0 g impure
sample of Na2CO3 is dissolved completely in water; then treated with 3.00 mol L−1
HCl to evolve
1871 mL of gaseous CO2 at 25.0 °C and 100 kPa. The HCl solution is slowly added until the
evolution of gaseous CO2 is no longer observed.

a) Write down the balanced chemical equation for the reaction described above. Please include all
phases (i.e. aq, s, l, g, etc…).
b) What percent (by mass) of the impure sample is Na2CO3? Assume that the impure components
of the sample do not react with HCl.

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

Use PV = nRT and solve for n = mols CO2 evolved at the conditions listed. Remember if you use kPa then R is 8.314. Remember T must be in kelvin.

Convert mols CO2 to mols Na2CO3 knowing that 1 mol CO2 requires 1 mol Na2CO3.

Convert mols Na2CO3 to grams. g = mols x molar mass

Then %Na2CO3 = (g Na2CO3/10g)*100 = ?

a) To write the balanced chemical equation for the reaction between hydrochloric acid (HCl) and sodium carbonate (Na2CO3), we need to identify the chemical formula of each compound and the products formed.

The chemical formulas of the reactants are:
HCl (hydrochloric acid)
Na2CO3 (sodium carbonate)

The products formed are:
CO2 (carbon dioxide)
H2O (water)
NaCl (sodium chloride)

The balanced chemical equation for the reaction can be written as follows:

2HCl + Na2CO3 -> CO2 + H2O + 2NaCl

b) To determine the percent (by mass) of the impure sample that is Na2CO3, we need to first calculate the mass of Na2CO3 in the 10.0 g impure sample.

To do this, we need to know the molar mass of Na2CO3, which can be calculated by adding up the atomic masses of each element in the compound.

Na2CO3:
Na (sodium) - 22.99 g/mol
C (carbon) - 12.01 g/mol
O (oxygen) - 16.00 g/mol (there are three oxygen atoms)

Molar mass of Na2CO3:
2(22.99 g/mol) + 12.01 g/mol + 3(16.00 g/mol) = 105.99 g/mol

We can then use the molar mass of Na2CO3 to calculate the moles of Na2CO3 in the 10.0 g impure sample:

moles of Na2CO3 = mass of Na2CO3 / molar mass of Na2CO3
moles of Na2CO3 = 10.0 g / 105.99 g/mol

Next, we need to calculate the total mass of the impure sample. Since the impure components do not react with HCl, we can assume their mass remains constant:

total mass of impure sample = mass of Na2CO3 / percent (by mass) of Na2CO3

Then, we can calculate the percent (by mass) of Na2CO3 using the equation:

percent (by mass) of Na2CO3 = (mass of Na2CO3 / total mass of impure sample) x 100

By substituting the values and calculating, we can find the answer.