Chem 210 Sample Exam #1 Spring 2014

Chem 210 Sample Exam #1
Spring 2014
Dr. Baxley
Answers on the last page
This practice exam is longer than the in-class exam and should take maybe 20 minutes longer than the 80 minutes
that will be available on Thursday 2-20 for the exam.
Expect to name elements or write symbols, just like on quiz number 3 that was given on 2-13.
You will need the following items:
 Pencil (recommended) and eraser, or pen
 Non-programmable scientific calculator
 A rested, well-practiced brain
You will be given a periodic table and a copy of the Conversion Factors page in the ICH (page 8).
1. The statement “There is more traffic between 8 and 9 in the morning because I suggest that most people start
work at 9” is best classified as:
A) an observation
B) a hypothesis
C) an experiment
D) a theory
E) all the above
2. Compounds can be described as
A) mixtures of two or more pure substances.
B) mixtures of two or more elements that has a specific ratio between components.
C) two or more atoms of different elements chemically joined together.
D) heterogeneous mixtures.
E) homogeneous mixtures.
3. Which two statements are true about scientific theories (pick two answers)
A. Theories must explain all of the data
B. Theories must be proven true
C. Theories can be modified or rejected to accommodate new data
D. Theories are simple ideas that can be proposed even with insufficient evidence
E. Theories turn into scientific laws when proven true
4. The Scientific Method
A) is just a theory.
B) is a strict set of rules and procedures that lead to inarguable fact.
C) isn't used much in modern chemistry.
D) is based on continued observation and experiment.
E) is a framework for proving an argument you know to be true.
5. Which one of the following is true about liquids:
A) liquids have a definite volume and have a definite shape
B) liquids have a definite volume but no definite shape
C) liquids have no definite shape but have a definite volume
D) liquids have no definite shape and no definite volume
6. Which one of the following is true about solids:
A) solids have a definite volume and have a definite shape
B) solids have a definite volume but no definite shape
C) solids have no definite shape but have a definite volume
D) solids have no definite shape and no definite volume
7. A substance that can't be chemically broken down into simpler substances is
A) a homogeneous mixture.
B) an element.
C) a heterogeneous mixture.
D) a compound.
E) an electron.
8. A substance composed of two or more elements in a fixed, definite proportion is
A) a homogeneous mixture.
B) a heterogeneous mixture.
C) a compound.
D) a solution.
9. A physical change
A) occurs when iron rusts.
B) occurs when sugar is browned by heating into caramel.
C) occurs when glucose is converted into carbon dioxide and water within your cells.
D) occurs when water is evaporated.
E) occurs when propane is burned for heat.
10. A chemical change
A) occurs when baking soda reacts with vinegar to make carbon dioxide gas.
B) occurs when paper is shredded.
C) occurs when water is vaporized and turned into steam.
D) occurs when salt is dissolved in water.
E) occurs when powdered lemonade is stirred into water.
11. Which of the following represents a physical property?
A) Sodium metal is extremely reactive with chlorine gas.
B) Mercury is a silvery liquid at room temperature.
C) Aluminum has a tendency to "rust."
D) Butane is highly flammable.
E) Argon has an unreactive nature.
12. Define kinetic energy.
A) energy associated with the position or composition of an object
B) energy associated with the motion of an object
C) energy associated with the force of an object
D) energy associated with the gravity of an object
13. The outside temperature is 35°C, what is the temperature in K?
A) –238 K
B) 273 K
C) 235 K
D) 353 K
E) 308 K
14. Read the length of the metal bar with the correct number of significant figures.
A) 20 cm
B) 15 cm
C) 15.0 cm
D) 15.00 cm
E) 15.000 cm
15. How many significant figures are in 0.00523980 mL?
A) 3
B) 4
C) 5
D) 6
E) 7
16. A blueberry scone is an example of
A) a compound.
B) an element.
C) a heterogeneous mixture.
D) a homogeneous mixture.
17. Which one of the following statements about isotopes is TRUE?
A) Isotopes of the same element differ only in the number of electrons they contain.
B) Isotopes of an element have the same number of protons but a different number of neutrons.
C) Isotopes of the same element have the same mass.
D) Isotopes of the same element have greatly different chemical properties.
18. Identify each of the following as an (element, a compound, homogeneous mixture or heterogeneous mixture:
A. fresh salsa
B. tungsten
C. tin
D. clean, dry air
E. chocolate chip cookies (with no nuts)
F. maple syrup
On the real exam, there will be space for you to answer the questions. Please do your work on separate paper for the
practice exam (it’s not due of course).
19. Determine the volume of an object that has a mass of 455.6 g and a density of 19.3 g/cm 3.
20. Complete the following calculation, with the correct number of significant figures.
(433.621 - 333.9) × 11.900
21. How many mm are in 3.20 cm?
22. If an object has a density of 8.65 g/cm3, what is its density in units of kg/m3?
23. If the walls in a room are 955 square feet in area, and a gallon of paint covers 15 square yards, how many gallons
of paint are needed for the room? (3 ft = 1 yd)
24. A piece of metal ore weighs 8.25 g. When a student places it into a graduated cylinder containing water, the
liquid level rises from 21.25 mL to 26.47 mL. What is the density of the ore?
25. If the temperature is 128°F, what is the temperature in degrees celsius?
26. What wavelength of light would you report in units of nm, if the light had a wavelength of 9.90 x 10-10 m?
27. How many cm3 are contained in 3.77 × 104 mm3?
28. How many kL does a 8.55 × 108 cL sample contain?
29. The recommended adult dose of Elixophyllin , a drug used to treat asthma, is 6.00 mg/kg of body mass.
Calculate the dose in milligrams for a 115-lb person. 1 lb = 453.59 g.
30. A jogger at a medium speed can burn 475 Calories per hour. How many minutes are needed to burn off a 3
chocolate chip cookies (no nuts), if each cookie contains 50.0 Calories?
31. What mass (in g) of water can be heated from 20.0 °C to 95.0 °C if 47.0 kcal of energy is available? The specific
heat capacity of water is 4.184 J/(g °C).
32. How many protons, electrons, and neutrons exist in a neutral atom of Ti–50?
Protons ________________ electrons ________________ neutrons ________________
33. How many protons, electrons, and neutrons exist in a negative one ion of I–131?
Protons ________________ electrons ________________ neutrons ________________
34. A particular isotope has 33 neutrons and 24 electrons and exits as a +3 ion (a charged atom). Write the complete
atomic symbol of this isotope.
Expect to name elements or write symbols, just like on quiz number 3 that was given on 2-13, or on the 2nd practice
quiz #2 that is posted to the 210 website (named Quiz #2).
Answers on next page….
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Answers:
a. Heterogeneous mixture
b. Element
c. Element
d. Homogeneous mixture (N2, O2, water, CO2)
e. Heterogeneous mixture
f. Homogeneous mixture
23.6 mL
1.19 × 103
3.20 × 101 mm
8.65 × 103 kg/m3
7.1 gallons
1.58 g/mL
53.3 °C
0.990 nm
3.77 × 101 cm3
8.55 × 103 kL
313 mg
19.1 minutes
627 g
22 protons, 22 electrons, 28 neutrons
53 protons, 54 electrons, 78 neutrons
60 3+
Co
27