Name:  _____________________                              date:  __________________               period: _______

ch. 6 moles                  test                                           60 points (5 ec)                                    chemistry

In problems involving any calculation, show your work in an organized manner, include (i) any relevant equation (or formula), (ii) conversion factor(s), (iii) put the proper units in your calculations and answer, and (iv) have the proper number of significant figures in your answer.  If you use the online website, https://www.symbolab.com/solver, or associated app, then clearly state that you used the website / app and you don’t have to show the algebraic manipulation to solve the problem.

Academic Honesty:   The answers on this test / quiz are my own and I am using only the allowed set of notes as described in the syllabus and am only using a calculator or preceding website / app – I did not use any other website / app during the test / quiz.  I have not discussed the test questions with anyone during the test.  If you violate any of the preceding items or do not sign, your semester grade is a F.

                                                                                                Signature:  ___________________

1. Solve.  [15 points]

a.  5.0 kg water =  __ mole

b.  25 millimole of carbon dioxide = __  g of carbon dioxide

c. 88 trillion calcium chloride molecules  =  __ moles of calcium chloride

2.  A chemical’s empirical formula is C3H9N and the molar mass of the chemical is 177 g / mol; what is its chemical formula ?  [10 points]


3. A chemical has 2.0 g of carbon, 0.50 g of hydrogen, and 1.33 g of oxygen.  The molar mass of the chemical is 230 g / mole; what is its chemical formula ?  [20 points; weekly quiz problem]

4. The complete combustion of 2.0 g of a chemical with carbon, hydrogen, and oxygen generates 3.826 g of carbon dioxide and 2.348 g of water.  What is the chemical’s empirical formula ?  [20 points]