PLEASE HELP TIMED TEST Part 1: Does the diagram illustrate an endothermic or an exothermic reaction? Give
reasons in support of your answer.
Part 2: Describe how you can determine the total change in enthalpy and activation
energy from the diagram and if each is positive or negative.

If 1.63 times 10 negative 4 of helium dissolves in 100.0g of water, what is the concentration in parts per million

The drawing represents the movement of particles in a substance. what changes of state can this substance undergo

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.