Preparation of dimmol ammonium acetate
Preparation of raw materials
Selected high-quality acetic acid ($CH_3COOH $) and ammonia ($NH_3 $). Ammonia can be prepared by heating the mixture of ammonium salt and alkali, and the downward air method is used to collect it to ensure its purity. High-purity analytical pure reagents are selected for acetic acid to ensure the quality of the reaction. Prepare an appropriate amount of distilled water for dissolution and dilution.

Reaction principle
Acetic acid and ammonia undergo acid-base neutralization. The chemical equation is: $CH_3COOH + NH_3\ longrightarrow CH_3COONH_4 $. This reaction is rapid and complete, and ammonium acetate can be efficiently prepared.

Preparation steps
1. ** Solution preparation **: In a clean 1000 dollars $ml volumetric flask, accurately measure an appropriate amount of glacial acetic acid with the help of a pipette, slowly inject it into the volumetric flask, add about 500 dollars $ml of distilled water, and shake it to make a preliminary mixture. According to $n = cV $ ($n $is the amount of substance, $c $is the concentration, $V $is the volume), calculate the amount of acetic acid required to prepare 2 dollars $mmol ammonium acetate.
2. ** Ammonia gas is introduced **: The prepared and purified ammonia gas is slowly introduced into the above acetic acid solution through the airway. When the solution is introduced, close observation of the solution changes shows that the solution is slightly heated, which is caused by the exothermic reaction of neutralization. Continue to introduce ammonia until the pH value of the solution is close to 7 dollars. With the help of precision pH test paper or pH meter accurate measurement, the reaction is basically completed.
3. ** Bandwidth evaluation operation **: After the solution is cooled to room temperature, add distilled water to the volumetric flask to the scale line. The bandwidth evaluation process needs to be accurately added with a dropper to ensure that the concave liquid level of the solution is tangent to the scale line. Cover the bottle and reverse the volumetric flask several times to make the solution fully mixed. At this time, 2 dollars millimolar per liter of ammonium acetate solution is obtained.

Precautions
1. During the production and use of ammonia gas, because it has a strong irritating odor and is toxic, the operation should be carried out in a well-ventilated environment or in a fume hood to avoid inhalation of ammonia gas and prevent poisoning.
2. Acetic acid is corrosive. Be careful when measuring and transferring. Avoid contact with skin and clothing. If it is inadvertently touched, rinse with plenty of water immediately and seek medical attention in time.
3. When bandwidth evaluation, be sure to look at the scale line head-up to ensure accurate solution concentration. At the same time, the volumetric bottle needs to be checked for leaks before use to prevent solution leakage from affecting the results.