Section outline

  • 1737 table centerpiece featuring ornate containers for sugar and oil or vinegar.

    1737 table centerpiece with containers for sugar and oil or vinegar.
    ::第1737号桌,装有糖、油或醋的容器。

    What can you do with vinegar?
    ::你能拿醋怎么办?

    Vinegar ( dilute acetic acid) is available in every grocery store in the country. The large one-gallon jugs can be found in households everywhere. One magazine published an article listing 150 ways to use vinegar, from cleaning dirt off your computer to cleaning window blinds. A of vinegar and baking soda is an excellent way to clean sink drains. You can also clean your carpets and your piano keys. Not bad for something that you thought of only for putting on food.
    ::国内每家杂货店都有醋酸(醋酸),大片一加仑的罐子可在各家各户中找到。一本杂志发表了一篇文章,列出了150种使用醋的方法,从清理电脑上的泥土到清洁窗帘。一个醋和苏打水是清洁下水道的绝佳方法。你还可以清理地毯和钢琴钥匙。对于你认为只用来装食物的东西来说,这不坏。

    Carboxylic Acids
    ::心箱酸

    Organic acids such as acetic all contain a functional group called a carboxyl group .
    ::乙酸等有机酸都含有一个功能组,称为碳酸酯组。

      Chemical structure of a carboxyl group, featuring both carbonyl and hydroxyl components.

    The carboxyl group contains the C=O of the carbonyl group, with the carbon also being bonded to a hydroxyl (−OH) group. A carboxylic acid is an organic compound that contains the carboxyl functional group. The general formula for a carboxylic acid can be abbreviated as –COOH. The carbon atom of the carboxyl group may be attached to a hydrogen atom or to a carbon chain. The naming of a carboxylic acid is as follows: Name the parent compound by finding the longest continuous chain that contains the carboxyl group. Change the –e at the end of the name of the alkane to –oic acid .
    ::carboxyl 组包含碳基组的C=O, 碳也与氢氧( ~OH) 组捆绑在一起。 碳基酸是一种有机化合物, 含有碳基功能组。 碳基酸的一般公式可以缩写为- COOH。 碳基酸组的碳原子可以附在氢原子或碳链中。 碳基酸的名称如下: 找到含有碳基化合物组的最长连续链, 命名母体化合物 。 将碳基酸在烷名称末尾的碳原子改为 - oic 酸 。

      Structural representation of a carboxylic acid showing the carboxyl functional group.

    Properties of Carboxylic Acids
    ::箱式酸的属性

    Carboxylic acids are all weak acids. In aqueous solution , the O−H bond of the hydroxyl group can break, yielding a negative carboxylate and the hydrogen ion.
    ::碳oxylic酸都是微弱的酸。 在水溶液中,氢氧化物组的O-H联系会破裂,产生负的碳化物和氢离子。

    Chemical structure of citric acid, a common carboxylic acid found in citrus fruits.

    Equilibrium between carboxyl group and carboxylate anion.
    ::蛋白质组和蛋白质阴离子之间的平衡。

    The smaller members of the aliphatic carboxylic acid series are colorless, volatile with strong odors. Ethanoic acid is commonly known as acetic acid and common household vinegar is a 5% solution of acetic acid. Larger carboxylic acids are solids with low points. There are a great many aromatic carboxylic acids, which are all crystalline solids. Carboxylic acids can form intermolecular and thus have relatively high melting and boiling points compared to other organic compounds that cannot hydrogen bond. Carboxylic acids with shorter carbon chains are very soluble in water, while those with longer carbon chains are less soluble.
    ::丙烯酸系列中较小的成员是无色的,挥发性强的芳香。乙酸通常被称为乙酸,常见的家用醋是乙酸的5%溶液。大碳酸是固态的,低点。有很多芳香的碳酸,都是晶状的固体。碳酸可以形成分子,因此与其他不能溶解氢的有机化合物相比,其熔点和沸点相对较高。碳链较短的碳酸在水中非常溶解,而碳链较长的碳链则不那么溶解。

    Many carboxylic acids occur naturally in plants and animals. Citrus fruits such as oranges and lemons contain citric acid.
    ::许多箱状酸自然出现在植物和动物中,柑橘和柠檬等柑橘类水果含有柠檬酸。

    Molecular structure of citric acid alongside a bowl of cut oranges.

    Citric acid is a large carboxylic acid with three ionizable hydrogen atoms. It is found in citrus fruits and gives them their sour or tart flavor.
    ::柠檬酸是一种大型箱式碳酸,含有三个可离子氢原子,在柑橘水果中发现,并给其酸性或酸性口味。

    Ethanoic and citric acids are frequently added to foods to give them a tart flavor. Benzoic, propanoic, and sorbic acids are used as food preservatives because of their ability to kill microorganisms that can lead to spoilage. Methanoic and ethanoic acids are widely used in industry as starting points for the manufacture of paints, adhesives, and coatings.
    ::乙醇酸和柠檬酸经常被添加到食物中,以给它们一种薄荷味。 苯并基、丙基和索比克酸被作为食品防腐剂,因为它们能够杀死可能导致腐蚀的微生物。 甲醇酸和含硫酸被工业广泛用作制造油漆、粘合剂和涂层的起点。

     

     

     

    Review
    ::回顾

    1. What is a carboxyl group?
      ::什么是卡本基组?
    2. Can carboxyl groups form hydrogen bonds?
      ::碳盒集团能形成氢债券吗?
    3. Do carboxylic acids ionize?
      ::蛋白酸离子化吗?