Chemistry 105A Exam I September 26, 2008
I certify I have not used a programming calculator for anything other than simple mathematical
operations.
_______________________________________ (Signature)
_______________________________________ (Printed name)
Multiple choice (20 questions, 3 pts. each) Darken the correct answer on the answer sheet. Remember
there are also 4 problems given after the multiple-choice questions. Budget your time accordingly.
1. Which of the following samples of matter represents a homogeneous mixture?
a) distilled water
b) wood
c) cement
d) black ink
2. Which scientist's experiment led to the nuclear model of the atom?
a) J.J. Thomson b) Ernest Rutherford
c) Robert Millikan d) Marie Curie
e) John Dalton
3. How many significant figures should there be in the answer to the following problem?
a) 2 b) 3 c) 4 d) 5
4. The density of the salt potassium chlorate is 2.32 g/cm3 at 20C. What is the volume, in cm3, of 0.83
lb of salt? (1 lb = 453.59 g)
a) 2.4 x 102 cm3b) 1.6 x 102 cm3c) 8.7 x 102 cm3d) 4.2 x 10-3 cm3
5. Water softener salt comes in 80 lb bags. Three 80 lb bags are used to fill a holding container and 12
lb of this salt is used per cycle of the softener column. If the softener cycles once every 5 days, how
many weeks will the salt in the container last?
a) 14 weeks b) 82 weeks c) 1.8 weeks d) 7.0 x 102 weeks
6. Lithium and nitrogen react to produce lithium nitride: 6 Li(s) +N2 (g) 2 Li3N(s)
How many moles of N2 are needed to react with 0.500 mole of lithium?
a) 3.00 b) 0.500 c) 0.167 d) 1.5 e) 0.0833
7. Fluorine 19 (19F) forms an F- ion which has how many protons, electrons, and neutrons?
CHE 105 Exam I - Fall 2008 WHITE 1/4
843.591.3595.365
