Calorie - Wikipedia. Calories are units of energy. Various definitions exist but fall into two broad categories. The small calorie or gram calorie (symbol: cal) is the approximate amount of energy needed to raise the temperature of one gram of water by one degree Celsius at a pressure of one atmosphere. It is equal to 7. One small calorie is approximately 4. The factor used to convert calories to joules at a given temperature is numerically equivalent to the specific heat capacity of water expressed in joules per kelvin per gram or per kilogram. The precise conversion factor depends on the definition adopted. In spite of its non- official status, the large calorie is still widely used as a unit of food energy. The small calorie is also often used for measurements in chemistry, although the amounts involved are typically recorded in kilocalories. The calorie was first defined by Nicolas Cl. The word comes from Latin calor meaning . Accordingly, several different precise definitions of the calorie have been used. The pressure is usually taken to be the standard atmospheric pressure (7. The temperature increase can be expressed as one kelvin, which means the same as an increment of one degree Celsius. Name. Symbol. Conversions. Notes. Thermochemical caloriecalth. Experimental values of this calorie ranged from 4. J. The CIPM in 1. J, noting an uncertainty of 0. J. This definition was adopted by the Fifth International Conference on Properties of Steam (London, July 1. Using the mean international ohm and volt (7.
Until 1. 94. 8, the latter was defined as 4. J was chosen to have the new thermochemical calorie represent the same quantity of energy as before. As if to avoid confusion, it is sometimes written Calorie (with a capital . Capitalization contravenes the rule that the initial letter of a unit name or its derivative shall be lower case in English. A nutritional requirement or consumption is often expressed in calories per day. One gram of fat in food contains nine kilocalories, while a gram of either a carbohydrate or a protein contains approximately four kilocalories. Even though it is not an SI unit, it is still used in chemistry. For example, the energy released in a chemical reaction per mole of reagent is occasionally expressed in kilocalories per mole. It is also occasionally used to specify energy quantities that relate to reaction energy, such as enthalpy of formation and the size of activation barriers. University of New Mexico. Retrieved 3. 0 April 2. PMID 1. 80. 86. 30. Bio. Med Central. Retrieved 3. 1 August 2. Annex B (informative): Other units given for information, especially regarding the conversion factor. International Organization for Standardization, 1. FAO (1. 97. 1). The 'Thermochemical calorie' was defined by Rossini simply as 4. J exactly). Pure and Applied Chemistry. Retrieved 2. 1 January 2. Handbook of Materials Science: General Properties, Volume 1. Retrieved 8 March 2. Compendium of Analytical Nomenclature(PDF) (3 ed.). Retrieved 3. 1 August 2. UK Metric Association. Retrieved 1. 7 April 2. National Physical Laboratory. Retrieved 8 February 2. Mediterranean 5 day diet is very yummy and fun to follow. The 1000 calorie menu that this diet provides calls for extra virgin olive oil, fresh herbs, lots of fresh.A 1000 calorie diabetic diet can help you manage your weight and your blood sugar levels. A sample menu and guidelines provided.
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