CHEM 101 Midterm: CHEM 101 Drexel CHEM 101 Exam 1 WINTER 09 10 with answers
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CHEM 101 WINTER 09-10 EXAM 1
On the answer sheet (Scantron) write you name, student ID number, and recitation section number.
Choose the best (most correct) answer for each question and enter it on your answer sheet.
Avogadro’s Number: 6.022 × 1023 mol-1
Speed of Light: c = 3.00 x 108 mys-1
Planck’s Constant: h = 6.626 x 10-34 Jys
Rydberg Constant: R = 2.179 x 10-18 J
E = hc/λ = hυ
1. Please chose the letter “a” as your answer for this question.
2. A possible explanation for several related initial observations is called a
a. law
b. model
c. hypothesis
d. qualitative statement
e. theory
3. Which of the following is both a quantitative and a qualitative statement?
a. The melting point of the compound was quickly determined by the student.
b. The filter funnel contained crystals of the orange precipitate.
c. The reaction produced 43 g of a greenish-yellow gas.
d. It was advertised as being 99.44 % pure.
e. The weight of the sample was determined to be 14.62 g.
4. Which of the following is a statement about a chemical property of iron?
a. Iron conducts electricity.
b. Iron conducts heat.
c. Iron melts at 1535°C.
d. Iron can be bent into shapes.
e. Iron rusts on exposure to water and oxygen.
5. Decane, a petroleum hydrocarbon, boils at 447°K. What is the boiling point in °C?
a. 316°C
b. 174°C
c. 237°C
d. 70°C
e. 720°C
6. Blood, iron, and lithium fluoride, respectively, are:
a. an element, a pure substance, and a heterogeneous mixture.
b. a pure substance, a pure substance, and a pure substance
c. a heterogeneous mixture, an element, and a pure substance.
d. an element, a homogeneous mixture, and a pure substance.
e. a homogeneous mixture, a pure substance, and a homogeneous mixture.
7. Which of the following is not a metal?
a. nickel (Ni, atomic number 28)
b. lithium (Li, atomic number 3)
c. phosphorus (P, atomic number 15)
d. uranium (U, atomic number 92)
e. calcium (Ca, atomic number 20)
8. Which of the following represents a pair of allotropes?
a. glucose and sucrose
b. air and oxygen
c. diamond and graphite
d. carbon monoxide and carbon dioxide
e. iodine and iodide
9. A sample of pure metal has a volume of 91 cm3 and a mass of 1755 g. What is the identity of the sample?
a. tantalum (density = 16.7 g/cm3)
b. mercury (density = 13.6 g/cm3)
c. osmium (density = 22.5 g/cm3)
d. tungsten (density = 19.3 g/cm3)
e. hafnium (density = 13.2 g/cm3)
10. When a neutral metal atom loses one or more electrons, ____ are formed.
a. neutrons
b. nuclei
c. ions
d. protons
e. gamma particles
11. Which two of the following represent a pair of isotopes?
Cl Ar O F Ar
I II III IV V
a. I and III
b. I and II
c. I and IV
d. II and V
e. III and IV
12. How many grams of chromium (Cr) contain the same number of atoms as 80 g of helium gas (He)?
a. 480 g
b. 52 g
c. 4 g
d. 59 g
e. 1040 g
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Document Summary
On the answer sheet (scantron) write you name, student id number, and recitation section number. Choose the best (most correct) answer for each question and enter it on your answer sheet. Speed of light: c = 3. 00 x 108 m(cid:121)s-1. Planck"s constant: h = 6. 626 x 10-34 j(cid:121)s. Rydberg constant: r = 2. 179 x 10-18 j. Iron conducts electricity: iron conducts heat, iron can be bent into shapes. Iron rusts on exposure to water and oxygen: decane, a petroleum hydrocarbon, boils at 447 k. When a neutral metal atom loses one or more electrons, ____ are formed: neutrons, nuclei, protons, gamma particles ions. Determine the number of molecules in a 250 mg table of ascorbic acid (vitaminc), c6h8o6: 1. 09 1024, 3. 34 1023. 3: 1. 81 10, 3. 34 1026, 8. 55 1020. Determine the percent water present in copper(ii) sulfate pentahydrate, cuso4 5h2o: 9. 86, 87. 0, 51. 2, 7. 31, 36. 0%
