11. (a) A 4.50 mol sample of an ideal gas is compressed irreversibly and isothermally at 96.22 K from an initial volume of 20.00 L in two steps: Step #1: Pext = 5.00 bar, Step #2: Pexe =
20.00 bar. Determine the value of the total work and heat involved.
(b) [2 marks] Describe in words what happens to the total amount of work if the compression
occurs in three steps.
(0) [2 marks] Assuming the process could be done in one or multiple steps and the process could
be reversible or irreversible, determine the minimum and maximum amount of work that could be
done to complete the compression.

The scheme below is from a series of reactions that are part of a synthesis of vitamin a. answer the following questions with reference to this scheme. (i) what is "reagent a"? (ii) draw a step-by-step mechanism which explains the formation of compound c from compound b (iii) which reagents would you use to form compound e from compounds c and d (reagents b and c)? for each reagent suggested above in (ii) explain the role of the reagent in the reaction to (iv) form compound e. you may wish to do this by drawing a mechanism. 1. addition of reagent a но reagent a 2. н, о" thо oh нон-с compound a. compound b. compound c .ch-оh 1. reagent b "сно 2. reagent c сh oh compound e. compound d.

This classification of drug typically changes the brain's chemistry and reduces its ability to create its own endorphins.

What happened to the amount of carbon dioxide in the atmosphere from 2010–2017?