Chemistry: Atom and Pure Silver

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CHEM 1405Name:_____________________
Exam # 1 (Chap. 1- 3) Score:

PART I – Multiple choice : (3 points each)

-------1. What is the term for the study of the composition and properties of matter?
a. geology b. chemistry c. alchemy d. physics

-------2. Express 10,000 as a power of 10.
a. 103 b. 10-5 c. 104 d. 105

-------3. How many significant digits are in 0.0250 cm3?
a. 5 b. 2 c. 3 d. 4

-------4. Which of the following unit equations is not correct? a. 20 dollars = 1 nickel b. 5 nickels = 1 quarter c. 5 pennies = 1 nickel d. 4 quarters = 1 dollar

-------5. Round off the measurement 968.543m to three significant digits. a. 968 m b. 9682.543 m c. 9680 m d. 9700 m

------6. A 4.500 g sample of silver-containing ore was analyzed and found to contain 1.268 g of pure silver. What is the percentage by mass of pure silver in the ore?
a. 28.18% b. 5.768% c. 5.768% d. 28.2%

-------7. Which statement about mass measurement is true?
a. Mass is measured using a balance and is not affected by Earth's gravity.
b. Mass is the force exerted by gravity on an object and is measured using a balance.
c. Mass is measured using a graduated cylinder and is not affected by gravity.
d. Both the mass and the weight of an astronaut are the same on the Moon and on Earth.

-------8. What is the name for the element F?
a. iron b. fluorine c. phosphorus d. flourine

-------9. Hydrogen peroxide is commonly used as an antiseptic and for bleaching. It is available commercially as a 3.0% solution by mass of hydrogen peroxide in water. How many grams of hydrogen peroxide are in a bottle containing 250.0 grams of solution?

a. 8333 g hydrogen peroxide b. 7.5 g hydrogen peroxide c. 8.3 x 103 g hydrogen peroxide d. 7.50 g hydrogen

-------10. Air is made up of nitrogen, oxygen, carbon dioxide, and other gases. Air is a(n) what?
a. pure substance b. mixture c. element d. compound

-------11. How many hydrogen atoms are in a molecule of acetic acid, HC2H3O2? a. 4 hydrogen atoms b. 3 hydrogen atoms
c. 1 hydrogen atom d. 2 hydrogen atoms

-------12. What mass of gold (specific heat = 0.0305 cal/g°C) releases 1.50 kcal of heat when it's cooled from 500.0°C to 25.0°C? a. 1.97 x 103 g b. 10.4 g c. 0.104 g d. 104 g

-------13. What is the basic unit of volume in the metric system? a. quart b. milliliter c. liter d. cm3

-------14. Which law states that energy is neither created nor destroyed? a. law of definite composition b. law of conservation of energy c. law of conservation of mass d. law of conservation of matter

-------15. The melting point of gold is about 1064°C. What is the equivalent Fahrenheit temperature?
a. 1915°F b. 623°F c. 1883°F d. 1947°F

-------16. Who is generally considered to be the founder of the scientific method?
a. Robert Boyle b. Paracelsus c. Aristotle d. Antoine Lavoisier

-------17. What is the term for the initial proposal that explains the data gathered in an experiment?
a. theory b. opinion c. appraisal d. hypothesis

-------18. Which of the following is a semimetal (metalloid)? a. zirconium b. bromine c. gallium d. arsenic

-------19. Which of the following...
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