For chemical drawings, you can use the Chemical Equation editor in the submission box for the assignment. You can also download a program called Marvin Sketch (https://chemaxon. com/products/marvin). 9. Draw the Lewis structure for sulfur tetrafluoride, SF4, and then draw the electron pair geometry. What’s the name of the molecular shape of sulfur tetrafluoride? Note: You can draw this on paper, take a picture, and paste the picture in your document. 10. Draw the structure of water. Is water considered polar or nonpolar? Why? Note: You can draw this on paper, take a picture, and paste the picture in your document. 11. When someone is injured, responding medical personnel may use either hot packs or cold packs to treat the injuries. These are examples of miniature chemical reactions. Using hot packs and cold packs as an example, explain the terms endothermic reaction and exothermic reaction.
12. Combustion reactions take place between a fuel and oxygen and produce carbon dioxide and water. Balance the following combustion reaction.

13. Aqueous lead (II) nitrate, Pb(NO3)2 undergoes a double displacement reaction with aqueous sodium chloride, NaCl, in which a precipitate forms. If the precipitate contains lead, write the balanced chemical equation for this reaction. Be sure to include the states of each of the reactants and products.
14. Explain the four basic types of chemical reactions. Be sure to include a sample equation for each type. Describe how rate relationships and activation energy are important in chemical reactions.
15. Write the equilibrium expression for the following reaction. Based upon the value of K, would you expect there to be more or less product in the equilibrium mixture? Why?

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o