If a molecule has only polar covalent bonds holding all the atoms together, is the molecule itself polar?

In which of these cases are the two wave points considered to be in phase with each other?

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.

In the reaction h2co3 (aq) + 3nh3 (aq) = 2 nh4+ (aq) + co3 2-, how many electrons are transferred?