Question 13 of 25 How has the work of chemists affected the environment over the years?
A. Chemists have both hurt the environment and helped the
environment by their actions.
B. Chemists have tried very hard not to impact the environment with
their work.
C. Chemists have ruined the environment through the misuse of
poisonous chemicals.
O D. Chemists have belan required to fix all environmental problems
that they have caused.

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.