1\documentclass{article}
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3\begin{document}
4
5\section{Chemistry}
6
7Ex:
8Soaps are essentially useless in acidic water, because in acidic water the carboxylate
9ions of soap molecules pick up hydogen ions to form the undissociated fatty acid:
10
11$$RCCO^- \quad + \quad H^+ \quad\longleftarrow\quad RCOOH$$
12
13$$RCCO^- \quad + \quad H^+ \quad\longrightarrow\quad RCOOH$$
14
15$$RCCO^- \quad + \quad H^+ \quad\longleftrightarrow\quad RCOOH$$
16
17$$RCCO^- \quad + \quad H^+ \quad\Longleftarrow\quad RCOOH$$
18
19$$RCCO^- \quad + \quad H^+ \quad\Longrightarrow\quad RCOOH$$
20
21$$RCCO^- \quad + \quad H^+ \quad\Longleftrightarrow\quad RCOOH$$
22
23$$RCCO^- \quad + \quad H^+ \quad\rightleftarrows\quad RCOOH$$
24
25$$RCCO^- \quad + \quad H^+ \quad\leftleftarrows\quad RCOOH$$
26
27$$RCCO^- \quad + \quad H^+ \quad\rightrightarrows\quad RCOOH$$
28
29$$RCCO^- \quad + \quad H^+ \quad\leftrightarrows\quad RCOOH$$
30
31\end{document}
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