In this lab exercise a solution containing K⁺ is passed down an ion exchange column containing a cation exchange resin in the acid form. The K⁺ ions in the solution replace the resin bound H₃O⁺ ions which elute from the column and then are titrated. This means that the column now holds the K⁺ ions. To use the column again we must "recharge" the column to remove K⁺ ions.

A 0.166 gram solution of K_xFe(C₂O₄)_yzH₂O is dissolved in water and the solution is passed down a column containing a cation exchange resin in the acid form. The eluted solution is then titrated with a standard NaOH solution to the first equivalence point. Experimentally it required 11.72 mL of a 0.112 M NaOH solution to reach the first equivalence point.

Calculate the number of moles of K⁺ in the weighted sample.

Calculate the mass (grams) of K⁺ in the weighted sample.

Calculate percent of potassium in the weighted sample.