Why do need need pure substances

When light strikes a plane mirror, images form in locations where light does not actually reach. it only appears to the observer as though the light were coming from this position. what type of image is formed?

For the following dehydrohalogenation (e2) reaction, draw the zaitsev product(s) resulting from elimination involving c3–c4 (i.e., the carbon atoms depicted with stereobonds). show the product stereochemistry clearly. if there is more than one organic product, both products may be drawn in the same box. ignore elimination involving c3 or c4 and any carbon atom other than c4 or c3.

12. calculate the hydroxide ion concentration of a solution with ph = 3.25. show all calculations leading to an answer