食醋放在熱水浴中, 離子會否因熱而少了?

Question

食醋放在熱水浴中, 離子會否因熱而少了?

Answer 1

If you put the vinegar in the hot water, due to the higher temperature, the ionization of the acetic acid may increase. However, more importantly, due to the acetic acid in the vinegr is easily evaporated due to its high vapor pressure. With the high temperature but not in a close system, the acetic acid in the hot wate will decrease significantly, no matter how the acetic acid ionized, the overall ion amount will still be less that the the original amount due to the loss of acetic acid.

I hope you can understand what I explained.

Answer 2

食醋的主要成份是稀乙酸溶液，它在水中離解成氫離子及乙酸根離子。
CH3COOH(aq) = CH3COO-(aq) + H+(aq) ΔH = +2.1 kJ mol-1

以上可逆反應中，正向反應是吸熱的。把食醋浸於熱水中，由於溫度升高，令平衡位置右移（傾向吸熱的反應），離子的濃度升高。