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प्रश्न
The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
उत्तर
\[\begin{array}{cc}
\ce{H}\phantom{..............}\ce{Cl}\phantom{................}\ce{F}\phantom{........}\\
\backslash\phantom{...............}\backslash\phantom{................}\backslash\phantom{......}\\
\ce{H - C - COOH Cl - C - COOH F - C - COOH}\\
/\phantom{...............}/\phantom{...............}/\phantom{.......}\\
\phantom{.}\ce{\underset{Acetic acid}{H}}\phantom{.....}\ce{\underset{Trichloroacetic acid}{Cl}}\phantom{...}\ce{\underset{Trifluoroacetic acid}{F}}\phantom{.......}\end{array}\]
Among H, Cl, and F, H is least electronegative while F is most electronegative. Then, F can withdraw electrons towards itself more than Cl and H. Thus, trifluoroacetic acid can easily lose H+ ions i.e., trifluoroacetic acid ionizes to the largest extent. Now, the more ions produced, the greater is the depression of the freezing point. Hence, the depression in the freezing point increases in the order:
Acetic acid < trichloroacetic acid < trifluoroacetic acid
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संबंधित प्रश्न
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| Henna is investigating the melting point of different salt solutions. She makes a salt solution using 10 mL of water with a known mass of NaCl salt. She puts the salt solution into a freezer and leaves it to freeze. She takes the frozen salt solution out of the freezer and measures the temperature when the frozen salt solution melts. She repeats each experiment. |
| S.No | Mass of the salt used in g |
Melting point in °C | |
| Readings Set 1 | Reading Set 2 | ||
| 1 | 0.3 | -1.9 | -1.9 |
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OR
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The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
