What is the percentage dissociation of a 0.020 mol dm−30.020\text{ mol dm}^{-3}0.020 mol dm−3 solution of ethanoic acid, CH3COOH\text{CH}_3\text{COOH}CH3COOH (Ka=1.80×10−5 mol dm−3K_{\text{a}} = 1.80 \times 10^{-5}\text{ mol dm}^{-3}Ka=1.80×10−5 mol dm−3)?
