Classify the following change as physical or chemical: a match lights when struck.
a. physical change
b. chemical change

Which of these would be caused by a chemical change? a) the formation of lava. b) sedimantary rock layering over time. c) metamorphic rock forming from igneous. d) metamorphic rock eroding to form sedimentary rock.

You mix the pks of succinic acid are 4.21 and 5.64. how many gramsa graduate student at sdsu wants to measure the activity of a particular enzyme at ph 4.0. to buffer her reaction, she will use a buffer system based on one of the acids listed below, which acid is most appropriate for the experiment? of monosodium succinate (fw = 140 g/mol) and disodium succinate (fw = 162 g/mol) must be added to 1 l of water to produce a solution with a ph 5.28 and a total solute concentration of 100 mm? (assume the total volume remains 1 liter, answer in grams monosodium succinate, grams disodium succinate, respectively.) volumes of 0.05 m nah2po4 and 0.05 m na2hpo4 (pk's for phosphoric acid are 2.15, 6.82 and 12.38). which of the following best describes the resulting solution?

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.