Carbon dioxide was passed through 300 g of a 1.12% potassium hydroxide solution until the mass fractions

Carbon dioxide was passed through 300 g of a 1.12% potassium hydroxide solution until the mass fractions of salts in the solution were equal. Calculate the volume of absorbed carbon dioxide.

Given:
m solution (KOH) = 300 g
ω (KOH) = 1.12%
ω (salt1) = ω (salt2)

To find:
V (CO2) -?

Decision:
1) KOH + CO2 => KHCO3;
2KOH + CO2 => K2CO3 + H2O;
2) m (KOH) = ω (KOH) * m solution (KOH) / 100% = 1.12% * 300/100% = 3.36 g;
3) n total (KOH) = m (KOH) / M (KOH) = 3.36 / 56 = 0.06 mol;
4) Let n1 (KOH) = (x) mol; then n2 (KOH) = (0.06 – x) mol;
5) n (KHCO3) = n1 (KOH) = (x) mol;
6) n (K2CO3) = n2 (KOH) / 2 = ((0.06 – x) / 2) mol;
7) ω (KHCO3) = ω (K2CO3);
m (KHCO3) = m (K2CO3);
n (KHCO3) * M (KHCO3) = n (K2CO3) * M (K2CO3);
x * 100 = ((0.06 – x) / 2) * 138;
x = 0.024;
8) n1 (KOH) = x = 0.024 mol;
9) n1 (CO2) = n1 (KOH) = 0.024 mol;
10) n2 (KOH) = 0.06 – x = 0.06 – 0.024 = 0.036 mol;
11) n2 (CO2) = n2 (KOH) / 2 = 0.036 / 2 = 0.018 mol;
12) n total (CO2) = n1 (CO2) + n2 (CO2) = 0.024 + 0.018 = 0.042 mol;
13) V (CO2) = n (CO2) * Vm = 0.042 * 22.4 = 0.94 l.

Answer: The CO2 volume is 0.94 liters.