Devise a detailed experimental procedure to purify ~ 20 grams of benzoic acid that is contaminated with sodium chloride. Justification of the steps (including solubility calculations) that are included in the procedure. In other words, explain why the steps are being included.

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.

27 drag each label to the correct location on the image. a particular exosolar system has five planets in total: a, b, c, d, and e. the table lists the orbital periods of these planets in days. planet orbital period (days) a 600 b 80 c 1,000 d 500 e 100 move each planet to its orbit in the system.

Suppose a pair of chemical compounds a and b can react in two different ways: a + b -> c reaction 1 gives product c. a + b -> d reaction 2 gives product d. the following facts are known about the two reactions: . reaction 1 is endothermic and reaction 2 is exothermic. if a reaction vessel is charged (filled) with a and b , then at first d is produced faster than c. use these facts to sketch a qualitative reaction energy diagram for both reactions. note: because these sketches are only qualitative, the energies don? t have to be exact. they only have to have the right relationship to each other. for example, if one energy is less than another, that fact should be clear in your sketch.