Please answer the following question: Information:  - Potassium bitartrate, also known as potassium hydrogen tartrate, with formula KCHO, is a byproduct of winemaking. In cooking it is known as cream of tartar. It is the potassium acid salt of tartaric acid (a carboxylic acid). It can be used in baking or as a cleaning solution (when mixed with an acidic solution such as lemon juice or white vinegar).  - An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group COOH. Sulfonic acids, containing the group SOOH, are relatively stronger acids. Alcohols, with OH, can act as acids but they are usually very weak. The relative stability of the conjugate base of the acid determines its acidity. Other groups can also confer acidity, usually weakly: the thiol group SH, the enol group, and the phenol group. In biological systems, organic compounds containing these groups are generally referred to as organic acids.  - A tartrate is a salt or ester of the organic compound tartaric acid, a dicarboxylic acid. The formula of the tartrate dianion is OOC-CH(OH)-CH(OH)-COO or CHO.   - Sodium bicarbonate (IUPAC name: sodium hydrogen carbonate) is a chemical compound with the formula NaHCO. It is a salt composed of sodium ions and bicarbonate ions. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate). The natural mineral form is nahcolite. It is a component of the mineral natron and is found dissolved in many mineral springs. It is among the food additives encoded by the European Union, identified as E 500. Since it has long been known and is widely used, the salt has many related names such as baking soda, bread soda, cooking soda, and bicarbonate of soda. In colloquial usage, the names sodium bicarbonate and bicarbonate of soda are often truncated. Forms such as sodium bicarb, bicarb soda, bicarbonate, bicarb, or even bica are common. The word "saleratus", from Latin "sal æratus" meaning "aerated salt", was widely used in the 19th century for both sodium bicarbonate and potassium bicarbonate.  - A leaven , often called a leavening agent (and also known as a raising agent), is any one of a number of substances used in doughs and batters that cause a foaming action (gas bubbles) that lightens and softens. An alternative or supplement to leavening agents is a mechanical action by which air is incorporated. Leavening agents can be biological or synthetic chemical compounds. The gas produced is often carbon dioxide, or occasionally hydrogen, or another.   - Winemaking or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from other fruits or plants. Mead is a wine that is made with honey being the primary ingredient after water.  - Racemic acid is an old name for an optically inactive or racemic form of tartaric acid . It is an equal mixture of two mirror - image isomers ( enantiomers ) , optically active in opposing directions . Its sodium - ammonium salt is unusual among racemic mixtures in that during crystallization it can separate out into two kinds of crystals , each composed of one isomer , and whose macroscopic shapes are mirror images of each other . Thus , Louis Pasteur was able to separate the two enantiomers by picking apart the crystals . In a modern - time re-enactment of the Pasteur experiment , it was established that the preparation of crystals was not very reproducible . The crystals deformed , but they were large enough to inspect with the naked eye ( microscope not required ) .  - A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus "Vitis".  - Tartaric acid is a white crystalline organic acid that occurs naturally in many plants, most notably in grapes. Its salt, potassium bitartrate, commonly known as cream of tartar, develops naturally in the process of winemaking. It is commonly mixed with sodium bicarbonate and is sold as baking powder used as a leavening agent in food preparation. The acid itself is added to foods as an antioxidant and to impart its distinctive sour taste.  - Baking powder is a dry chemical leavening agent, a mixture of a carbonate or bicarbonate and a weak acid, and is used for increasing the volume and lightening the texture of baked goods. Baking powder works by releasing carbon dioxide gas into a batter or dough through an acid-base reaction, causing bubbles in the wet mixture to expand and thus leavening the mixture. It is used instead of yeast for end-products where fermentation flavors would be undesirable or where the batter lacks the elastic structure to hold gas bubbles for more than a few minutes, or to speed the production. Because carbon dioxide is released at a faster rate through the acid-base reaction than through fermentation, breads made by chemical leavening are called quick breads.  - An antioxidant is a molecule that inhibits the oxidation of other molecules. Oxidation is a chemical reaction that can produce free radicals, leading to chain reactions that may damage cells. Antioxidants such as thiols or ascorbic acid (vitamin C) terminate these chain reactions. The term "antioxidant" is mainly used for two different groups of substances: industrial chemicals which are added to products to prevent oxidation, and natural chemicals found in foods and body tissue which are said to have beneficial health effects.    Given the information above, choose from the list below the object entity that exhibits the relation 'instance of' with the subject 'racemic acid'.  Choices: - acid  - action  - base  - bread  - carboxylic acid  - century  - chain  - chemical  - chemical compound  - chemical reaction  - damage  - dicarboxylic acid  - dough  - food  - gas  - genus  - grape  - hydrogen  - may  - mineral  - mixture  - molecule  - name  - number  - organic acid  - organic compound  - plant  - preparation  - production  - salt  - solution  - union  - vitamin  - volume  - wine  - word
A:
chemical compound