aquaducts in rome essays

aquaducts in rome essays In this short paper I will discuss three main subjects. One will be the problem regarding landowners and their responsibility towards aqueduct maintenance. Second, Ill introduce my source of information and give a short summary of it. Third and finally I will discuss and answer some main questions from the textbook asking about the proclamation sent by Emperor Theodosius. The problem was maintenance on the aqueducts. Who was responsible for the upkeep? For those responsible, what were their duties and obligations for the upkeep of the aqueducts? What were the penalties if they didnt do their duties? This was the problem. Emperor Theodosius, of the Roman Empire resolved these questions by his proclamation in 438 A.D. In his proclamation he makes the responsibility of the upkeep and maintenance of the aqueducts to the landowner that the aqueducts pass through. The Emperor goes on to state that because of this extra duties on the landowners shall be exempt from extraordinary burdens (Discovering the Western Past, pg. 15 5th paragraph second line), (Discovering the Western Past, pg. 15. 5th paragraph 2nd line). Since, the landowners were responsible for the upkeep, they were responsible for clearing the aqueduct out when it was clogged of dirt and soot. In addition, they were responsible for keeping trees trimmed away from the aqueducts. If the landowner did not keep up with his duties on the aqueduct the punishment for this was the forfeiture of his lands to the imperial treasury. The textbook Discovering the Western Past, asked many questions ranging from the complexity of the machines to the simple tools that these civilizations had to use. What were the political ramifications of the decisions the emperor made? Why not just hire more people to do the job or even better buy slaves and make them continue to do the upkeep? Well, for a couple of reasons why the emperor didnt hire or buy s...

Primary Standards in Chemistry

Primary Standards in Chemistry In chemistry, a primary standard is a reagent which is very pure, representative of the number of moles the substance contains and easily weighed. A reagent is a chemical that is used to cause a chemical reaction with another substance. Often, reagents are used to test for the presence or quantity of specific chemicals in a solution. Properties of Primary Standards Primary standards are typically used in titration to determine an unknown concentration and in other analytical chemistry  techniques. Titration is a process in which small amounts of a reagent are added to a solution until a chemical reaction occurs. The reaction provides confirmation that the solution is at a specific concentration. Primary standards are often used to make standard solutions (a solution with a precisely known concentration). A good primary standard meets the following criteria: high level of puritylow reactivity (high stability)high equivalent weight (to reduce error from mass measurements)not likely to absorb moisture from the air (hygroscopic) to reduce changes in mass in humid versus dry environmentsnon-toxicinexpensive and readily available In practice, few chemicals used as primary standards meet all of these criteria, although its critical that  a standard is of high purity. Also, a compound which may be a good primary standard for one purpose may not be the best choice for another analysis. Examples of Primary Standards and Their Uses It may seem odd that a reagent is needed to establish the concentration of a chemical in solution. In theory, it should be possible to simply divide the mass of the chemical by the volume of the solution. But in practice, this isnt always possible. For example, sodium hydroxide (NaOH) tends to absorb moisture and carbon dioxide from the atmosphere, thus changing its concentration. A 1-gram sample of NaOH may not actually contain 1 gram of NaOH because additional water and carbon dioxide may have diluted the solution. To check the concentration of NaOH, a chemist must titrate a primary standard (in this case a solution of potassium hydrogen phthalate (KHP). KHP does not absorb water or carbon dioxide, and it can provide visual confirmation that a 1 gram solution of NaOH really contains 1 gram. There are many examples of primary standards; a few of the most common include: Sodium chloride (NaCl) is used as a primary standard for silver nitrate (AgNO3) reactions.Zinc powder may be used to standardize EDTA solutions after it has been dissolved in hydrochloric acid or sulfuric acid.Potassium hydrogen phthalate or KHP may be used to standardize perchloric acid and an aqueous base in an acetic acid solution. Secondary Standard Definition A related term is secondary standard. A secondary standard is a chemical that has been standardized against a primary standard for use in a specific analysis. Secondary standards are commonly used to calibrate analytical methods. NaOH, once its concentration has been validated through the use of a primary standard, is often used as a secondary standard.