Answer:
(1)NBS, ROOR (2) and (3)HBr, ROOR
Explanation:
Conversion of ethylbenzene to (2-bromoethyl)benzene involves three steps.
First step: allylic bromination of ethylbenzene in presence of NBS, ROOR. This step produces (1-bromoethyl)benzene.
Second step: E2 ellimination of HBr from (1-bromoethyl)benzene in presence of a strong base e.g. potassium t-butoxide []. This step produces styrene
Third step: HBr addition to double bond in presence of HBr, ROOR (antimarkonikov addition of HBr). Thus step produces (2-bromoethyl)benzene.
Full reaction scheme has been shown below.
The main field of science that studies atoms and molecules is called chemistry.
Answer:
The correct answer is - Luster.
Explanation:
Luster is a property that explains how the light is reflected on the surface of a mineral. Luster can be categorized with the help of if an element or mineral is metallic or non-metallic.
Pyrite has a shiny, opaque metallic luster which is similar to other metals. There are different types of luster other than metallic also found like, silky, dusty, pearly, waxy, and a few more.
The given statement about standard heat of formation is true.
Explanation:
Yes, it is true that standard heat of formation is same as standard enthalpy of formation. As enthalpy is termed for change in the heat energy occurred in the process of completion of any chemical reaction, the standard enthalpy or heat of formation is termed as the heat energy required to form 1 mole of any substance in its standard state from its original, parent or constituent elements in their standard state. Basically, it defines the amount of energy required by the system or compound for its formation from different elements under different synthesis conditions but the nature of the parent samples and temperature and pressure should be kept standard.
So the given statement is true.