Practice Exam 1 for Chemistry 163

  1. Homogeneous mixtures are also known as ______.
  1. Compounds
  2. Elements
  3. Solutions
  4. Solids
  5. Substances
  1. What subatomic particle or particles are found inside the nucleus of an atom?
  1. Neutron
  2. Electron
  3. Proton
  4. Electrons and Neutrons
  5. Protons and Neutrons
  1. The charge on an electron was determined ______.
  1. by J.J. Thompson in cathode ray tube experiments.
  2. by Millikan in his oil-drop experiment.
  3. by Rutherford in the gold foil experiment
  4. in the postulates of Dalton’s atomic theory.
  1. Which of the following is a chemical property of chlorine, Cl2?
  1. It is a yellow gas.
  2. It has a density of 3.2 g/L.
  3. It burns in sodium vapor.
  4. It boils at -34°C.
  1. Which of the following is a physical transformation?
  1. Combustion of CH2 gas
  2. Rusting of Fe to form FeO
  3. Sublimation of H2O solid to H20 gas
  4. Mixing HCl and O2 to form HClO4
  1. Rusty measures the radius of a coffee table to be 2.4 ft. Kathy measures the same table to be 2.1 ft. The true radius of the coffee table is 2.25ft.

Which of the following statements is TRUE?

  1. Rusty is more precise
  2. Rusty and Kathy need to make more measurements to determine who is more precise
  3. Kathy is more accurate
  4. Rusty is more accurate
  5. None of the above statements are true.
  1. Which of the following has exactly four significant digits?
  1. 1800
  2. 0.023
  3. 4.075
  4. 0.349
  1. Which of the following answers has the wrong number of significant digits?
  1. 6.78 / .036 = 188.3
  2. 2.331 - 0.9 = 1.4
  3. 6.10 – 5.9/ 6.210 x 10^-2
  1. If matter is uniform throughout, cannot be separated into other substance by physical processes, but can be decomposed into other substances by chemical processes, it is called_____.
  1. a compound
  2. an element
  3. a mixture of elements
  4. a heterogeneous mixture
  5. a homogeneous mixture
  1. Fill in the gaps in the following table.

Symbol / 56Fe^3+
26
Protons / 76
Neutrons / 116
Electrons / 72
Mass number
Net charge
  1. Convert -8.00°F to Celsius and Kelvin.
  1. A car traveling at 96.0 miles per hour has to make a trip of 239.0 miles. How many minutes will the trip take?
  1. Chlorine has a density of 3.21g/L. Suppose you have 100.0 mg of chlorine. What volume in liters will the chlorine occupy?
  1. The specific heat of copper is 0.385 J/gC. How much heat energy in kilojoules is required to raise the temperature of 908 g of copper from 40.0C to 75.0C?
  1. What is the diameter of a single iron atom in meters if it’s diameter is 1.73 x 10^-5 µm?
  1. How many joules does it take to raise the temperature of 3.50L of water from 22.0°C to 44.0°C? How many kilojoules? Take the density of water to be 1.00g/mL.
  1. Suppose 14.0g of magnesium (Mg) reacts with 63.0g of chloride to give 70.0g of the compound magnesium chloride (MgCl2). In the process, all the magnesium gets used up, but some elemental chloride is left over.

a)For the law of conversation of mass to be obeyed, how much chloride is unused?

b)What is the percent Mg in MgCl2?

c)What is the percent Cl in MgCl2?

d)What is the sum of the %Mg and %Cl in MgCl2?

  1. The compound carbon disulfide (CS2) has a total mass of 76.15g, 12.01 g of carbon and 64.14g of sulfur. What is the mass of carbon in another sample of carbon disulfide, if the mass of sulfur is 21.38?
  1. A new element Uranium has 2 isotopes, Uranium 235 and Uranium 237. The isotopes masses are shown below.

Uranium-235 (234.99 amu, 78.09% abundance)

Uranium-237 (237.34 amu)

  1. What is the percent abundance of the Uranium 237 isotope?
  1. Calculate the weighted average of the atomic mass of naturally occurring uranium.