Which of the following describes the law of conservation of mass? A.) Reactants + Products = 100%
B.) Matter (mass) cannot be created or destroyed in ordinary chemical and physical changes, but it can change form
C.) Mass of products does not equal mass of reactants
D.) Matter (mass) can be created or destroyed in certain chemical reactions

Which of the following signs of a chemical reaction are observed in the reaction of potassium with water? precipitate formed temperature change smell produced gas produced color change

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.

Which compound most likely has the greatest bond energy?