Chem 121
Examples of Problems from the ACS Exam Study Guide
These were chosen at random from the study guide and is not meant to represent what is likely to be in
the exam.
1. Which is true about equal volumes of CH4 and O2 gases at 20°C and 1 atm pressure?
A. The CH4 sample has a mass that is one-half that of the O2 sample.
B. The number of O2 molecules is twice as large as the number of CH4 molecules.
C. The average kinetic energy of the O2 molecules is one-half that of the CH4 molecules.
D. The average velocity of the O2 molecules is one-half that of the CH4 molecules.
2. A 10.0 g sample of silver is heated to 100.0 C and then added to 20.0 g of water 23.0°C in an
insulated calorimeter. AT thermal equilibrium, the temperature of the system was measured as 25.0 °C.
What is the specific heat of silver?
Given: Specific Heat Data: H2O (l) 4.184 J g 1 °C
A. 0.053 J g 1 °C
1
B. 0.22 g 1 °C
1
1
C. 4.5 g 1 °C
1
D. 8.4 g 1 °C
1
3. An atom has a valence shell electron configuration of ns1. To which group of elements in the
periodic table does it belong?
A. transition elements
B. lanthanides
C. alkaline earth metals
D. alkali metals