Loading...
C or UC
Quiz by chitlada Chek
Customize this quiz to suit your class
Instantly translate to 100+ languages
Tag the questions with any skills you have. Your dashboard will track each student's mastery of each skill.
Give this quiz to my class
E,C or M?Croos a,b,c or d for the correct answer!Beginning consonant C or KDo Now 9/29 (A and C) or 9/30 (B)p or cOrganic Nomenclature. What are aliphatic compounds or aliphatic hydrocarbons? An aliphatic compound or aliphatic hydrocarbon is an organic compound containing hydrogen and carbon atoms that are usually linked together in chains that are straight. The term Aliphatic has been derived from the Greek word “Aleiphar” which translates to “fat”. It is used to describe hydrocarbons that are obtained by the chemical degradation of oils or fats. What are aliphatic compounds or aliphatic hydrocarbons? The simplest organic compounds are those composed of only two elements: carbon and hydrogen. These compounds are called hydrocarbons. Hydrocarbons are separated into two types: aliphatic hydrocarbons and aromatic hydrocarbons. Aliphatic hydrocarbons are hydrocarbons based on chains of C atoms. There are three types of aliphatic hydrocarbons: Alkanes are aliphatic hydrocarbons with only single covalent bonds. Alkenes are hydrocarbons that contain at least one C–C double bond, and alkynes are hydrocarbons that contain a C–C triple bond. Occasionally, we find an aliphatic hydrocarbon with a ring of C atoms; these hydrocarbons are called cycloalkanes (or cycloalkenes or cycloalkynes). The simplest alkanes have their C atoms bonded in a straight chain; these are called normal alkanes. They are named according to the number of C atoms in the chain. The smallest alkane is methane: molecule is three dimensional, with the H atoms in the positions of the four corners of a tetrahedron. The diagrams representing alkanes are called structural formulas because they show the structure of the molecule. As molecules get larger, structural formulas become more and more complex. One way around this is to use a condensed structural formula, which lists the formula of each C atom in the backbone of the Molecule. The condensed formulas show hydrogen atoms right next to the carbon atoms to which they are attached, as illustrated for butane: The ultimate condensed formula is a line-angle formula (or line drawing) , in which carbon atoms are implied at the corners and ends of lines, and each carbon atom is understood to be attached to enough hydrogen atoms to give each carbon atom four bonds. For example, we can represent pentane (CH3CH2CH2CH2CH3) and isopentane [(CH3)2CHCH2CH3] as follows: Unsaturated Hydocarbons: Alkenes and Alkynes Alkenes Organic compounds that contain one or more double or triple bonds between carbon atoms are described as unsaturated. Unsaturated hydrocarbons have less than the maximum number of H atoms possible. Unsaturated hydrocarbon molecules that contain one or more double bonds are called alkenes. Carbon atoms linked by a double bond are bound together by two bonds, one σ bond and one π bond. Double and triple bonds give rise to a different geometry around the carbon atom that participates in them, leading to important differences in molecular shape and properties. The differing geometries are responsible for the different properties of unsaturated versus saturated fats. Naming Alkenes and Alkynes Alkenes and alkynes are named in a similar fashion. The biggest difference is that when identifying the longest carbon chain, it must contain the C–C double or triple bond. Furthermore, when numbering the main chain, the double or triple bond gets the lowest possible number. This means that there may be longer or higher-numbered substituents than may be allowed if the molecule were an alkane. For example, this molecule is 2,4-dimethyl-3-heptene (note the number and the hyphens that indicate the position of the double bond). Unsaturated Hydocarbons: Alkenes and Alkynes Unsaturated Hydocarbons: Alkenes and Alkynes Alkynes Hydrocarbon molecules with one or more triple bonds are called alkynes; they make up another series of unsaturated hydrocarbons. Two carbon atoms joined by a triple bond are bound together by one σ bond and two π bonds. The sp-hybridized carbons involved in the triple bond have bond angles of 180°, giving these types of bonds a linear, rod-like shape. The simplest member of the alkyne series is ethyne, C2H2, commonly called acetylene. The Lewis structure for ethyne, a linear molecule, is: Properties of Unsaturated Hydocarbons: Alkenes and Alkynes Ethylene (the common industrial name for ethene) is a basic raw material in the production of polyethylene and other important compounds. Over 135 million tons of ethylene were produced worldwide in 2010 for use in the polymer, petrochemical, and plastic industries. Ethylene is produced industrially in a process called cracking, in which the long hydrocarbon chains in a petroleum mixture are broken into smaller molecules. Halogens can also react with alkenes and alkynes, but the reaction is different. In these cases, the halogen reacts with the C–C double or triple bond and inserts itself onto each C atom involved in the multiple bonds. This reaction is called an addition reaction. One example is Properties of Unsaturated Hydocarbons: Alkenes and Alkynes Hydrogen can also be added across a multiple bond; this reaction is called a hydrogenation reaction. In this case, however, the reaction conditions may not be mild; high pressures of H2 gas may be necessary. A platinum or palladium catalyst is usually employed to get the reaction to proceed at a reasonable pace: CH2=CH2+H2→metalcatalystCH3CH3 CH2=CH2+H2→metalcatalystCH3CH3. Listen to the conversation between Nam and Mrs Nhi, his aunt. Circle the best answer A, B, or C.1. What is the primary goal of the board regarding compensation for professional employees? A) To minimize costs B) To attract and retain committed personnel C) To follow state regulations only D) To offer the highest salaries in the district 2. How is the compensation of certificated personnel determined? A) Based solely on local market rates B) Based on the state salary schedule with local supplements C) Based on the number of students taught D) At the discretion of the principal 3. When must teachers receive written notification of their employment status for the following school year? A) After the school year ends B) On the last day of school C) On or before the date the district extends offers of teaching employment D) At the start of the school year 4. Who has the authority to establish the compensation for support staff? A) The school board B) The superintendent C) The principal D) The teachers’ union 5. How often are employees paid? A) Weekly B) Monthly C) Semi-monthly D) Annually 6. What happens if a regular payday falls on a company-observed holiday? A) Employees are paid the following week B) Employees are paid on the last business day preceding that date C) Employees receive double pay D) Payments are canceled 7. Which of the following is NOT a mandatory deduction from an employee’s compensation? A) Federal income taxes B) State income taxes C) Employee bonuses D) FICA taxes 8. How should an employee report an improper deduction from their pay? A) Ignore it B) Report it to human resources or their direct supervisor C) Discuss it with colleagues D) Write a letter to the school board 9. Which of the following statements is true regarding exempt employees’ salaries? A) Their salary can be reduced for any reason. B) They receive full salary regardless of the number of hours worked in a week. C) Their pay is based on the number of days they work. D) They are paid hourly. 10. Under what condition can the district reduce an exempt employee's salary? A) If the employee takes vacation days B) If the employee is absent for personal reasons for one or more full days C) For minor conduct infractions D) If the employee decides to leave early