♥ Quiz October 16-17, 2006

Name

    This is an individual quiz; open book; open notes.
Circle the number of, and answer only ONE of the first two questions. Answer the remainder of the questions. For bonus, you may answer the non-selected of the first two, and receive half credit for whatever you get right.

  1. (24 pts) Fill in the blank spaces in the following chart.

    ItemWeightMolesMillimolesDaltons
    K2CO392.0 grams0.666666138.21
    NaBr20.1 grams0.195195102.90

  2. (28 pts) Very few inorganic compounds form insoluble chlorides in water. The three that do are silver, mercury(I), and lead. Jason took 300 mg of mercurous nitrate (Hg2(NO3)2) and stirred it into 25 ml of distilled water and obtained a clear solution. He then made a second solution by adding 0.15 gram of NaCl to 10 ml of distilled water. He then mixed the two solutions and obtained a copious amount of product, a white precipitate of Hg2Cl2. (Hg2(NO3)2 = 525.22 dal; Hg2Cl2 = 472.09 dal; NaCl = 58.44 dal)

    1. Which reactant was the limiting one?

      0.57 mmoles Hg2(NO3)2; 2.57 mmoles NaCl

    2. How many millimoles of Hg2Cl2 should have formed?

      0.57 mmoles

    3. How many milligrams of Hg2Cl2 should have formed?

      269 mg

  3. (10 pts) Today's lab will be on the subject of how survival experts can make water safe by boiling it in a pot make of leaves by throwing hot rocks into the water taken from a stream. Of course, if they had a metal pot, they could just put the pot over the fire, but they don't have a pot. Anyway, what is the scientific principle that is being used to boil the water with the hot rocks?

    Heat Capacity: the heat stored up in the fired rocks is transferred to the stream water.


  4. (1 pt each; wrong names will be subtracted from right ones!) List the names of internationally known scientists who have made major contributions to the understanding of chemistry. (The list does not include Drs. Faile or Vermeulen!)

    Avagadro, Charles, Einstein, Mendeleyev....