Ethanol, acetaldehyde, acetic acid are distinguished not identified by reagents .

All three substances have active hydrogen and can react with NA.

The latter three substances are all alkaline, so only acetic acid can react with them.

Ethanol, acetaldehyde, acetic acid.

Na, yes or no.

Naoh, no, no.

naco3, no, no.

NaHCO3 No, no, no.

Newly produced copper hydroxide.

Take 1ml of each of the above solutions in the test tube, and add the new copper hydroxide turbidity solution drop by drop.

Formic acid: first, the turbid liquid is dissolved, and after adding too much, a red precipitate is generated.

Acetic acid: first, the turbid liquid is dissolved, and then heated without red precipitate (there is a black precipitate).

Acetaldehyde has a brick-red precipitate, and propanol does not

What chemical method is used to identify acetic acid and ethanol:

1. Smell the gas method, the one with the smell of wine is ethanol, and the one with the sour taste is acetic acid;

2. Combustion method, a small amount of liquid is taken close to the outer flame of the alcohol lamp with platinum silk fermentation, and the flame produced by combustion is ethanol, and vice versa, acetic acid;

3. Chemical reagent method, take a small amount of liquid to the test tube, add litmus test solution, turn red is acetic acid, and vice versa is ethanol;

4. Chemical reaction method, take a small amount of liquid silver locust body, add a strong reducible active metal element, acetic acid produced by bubbles, and ethanol if there is bubbles;

5. Sodium carbonate reacts with acetic acid to release a large amount of gas, which is miscible with ethanol;

7. Add gasoline, soluble as ethanol, insoluble as acetic acid; Do nothing.

8. The newly made copper hydroxide plus acetic acid will precipitate and dissolve to obtain a clear and transparent blue solution;

9. High concentration of acetic acid dissolved in water will be exothermic;

10. Use pH test paper, the test paper turns red is acetic acid, and vice versa.

Ethylene glycol is o-diol, adding copper sulfate and sodium hydroxide will produce a crimson blue solution (cu and two hydroxyl groups form a coordination bond), methanol and ethanol can be identified by potassium permanganate, methanol oxidation product is carbon dioxide, which can make clarified lime water turbid, and ethanol oxidation product is acetic acid.

Reagent: Use a new copper hydroxide suspension.

Phenomenon: 1. Formic acid dissolves the newly produced copper hydroxide (neutralizes acid and alkali), and heats to produce (brick) red precipitate (because there are aldehyde groups in formic acid).

2. Acetaldehyde mixed with copper hydroxide is heated to produce (brick) red precipitation, which is not dissolved by copper hydroxide.

3. Acetic acid dissolves copper hydroxide, and heating does not produce (brick) red precipitation.

Related knowledge: Formic acid contains both carboxyl and aldehyde groups;

Aldehyde and newly made copper hydroxide are coheated to generate brick-red precipitated Cu2O, and aldehydes are oxidized to the corresponding carboxylic acids;

Carboxylic acids can neutralize copper hydroxide to dissolve copper hydroxide;

The equation is: <>

The following reagents cannot be used to distinguish between ethanol and acetic acid:a

a Distilled waterb Sodium carbonate solution c Purple litmus solution d Acidic acacia cherry potassium permanganate solution.

Analysis:

Ethanol and acetic acid are miscible with water, and water cannot distinguish between the two. Sodium carbonate and acetic acid react to release gas, while ethanol and sodium carbonate do not. Acetic acid selects acidity, so that the purple litmus rot bush test solution is red, and ethanol cannot.

Ethanol can fade the acidic potassium permanganate solution, but ethyl nucleic acid cannot, so the answer is A.

The most direct way to distinguish between acetic acid and ethanol is to smell the smell, acetic acid has a very vinegar taste, even a little pungent, and ethanol has a smell of wine. Another method is to test with pH test strips, take two test strips, drop one drop on the test strip with a dropper, and then compare it with the color card, the smaller pH value is acetic acid.

Add calcium carbonate, acetic acid has a reaction: 2CH3COOH+CAC3=(CH3COO)2CA+H2O+CO2, add sodium bicarbonate powder, acetic acid is released with gas, and ethanol is without phenomenon.

A large group of organic compounds is compounds formed by the substitution of hydrogen atoms in the side chains of aliphatic hydrocarbons, alicyclic hydrocarbons or aromatic hydrocarbons with hydroxyl groups. Generally referred to as an alcohol, the hydroxyl group is attached to a saturated, sp3 hybrid carbon atom. If the hydroxyl group is attached to the benzene ring, it is a phenol; If the hydroxyl group is attached to the sp2 hybrid alkene carbon, it is an enol.

Phenols and enols are quite different from ordinary alcohols.

The reagent that can be used to distinguish acetaldehyde from ethanol is silver ammonia solution, which can react with acetaldehyde in silver mirror, but cannot react with ethanol to produce any phenomenon.

Combustion method: If the purity is high, a small amount of liquid can be taken close to the outer flame of the alcohol lamp with platinum wire fermentation, if the combustion produces flame, it is ethanol, and the one that does not burn is acetic acid.

Acetic acid and ethanol are very easy to distinguish because they both have a taste, and the sour smell of acetic acid is very strong, and if you fan the air with your hands, you can smell his sour smell a little farther away.

The pH test strip can be identified. In fact, your nose can distinguish that acetic acid has a sour smell and ethanol has a wine smell.