A compound of phosphorus and sulfur used in match heads contains 56.29% P and 43.71% S. The molar mass corresponding to the empirical formula of this compound is: (Atomic masses: P = 30.97; S = 32.04)

188.1 g / mol

220.1 g / mol

93.94 g / mol

251.0 g / mol

158.1 g / mol

The big bang nucleosynthesis theory states that elements were produced in the first few minutes of the big bang while elements have their origins in the interiors of stars, forming much later in the history of the universe.

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?

Pegmatites are igneous rocks in which the individual minerals are very large. typically, the minerals are all light-colored quartz, feldspar and muscovite. if you were given a black and white photograph of a pegmatite in a quarry (where the rock has been blasted and broken), what physical properties could you use to identify those three minerals in this hypothetical photo? describe each mineral and the specific diagnostic properties. be specific.