Question 1:
A mixture contains:
    50 mL benzene (m.w.=78) v.p. = 75 mm, Hg sp. gr. = 0.879.
    25 mL carbon tetrachloride (m.w. = 154), v.p. = 91 mm, Hg sp. gr. = 1.595
    25 mL trichloroethylene (m.w. = 131.5), v.p. = 58 mm, Hg sp. gr. = 1.455.

Assuming Raoult's Law is obeyed, what will be the concentration of benzene in air at 760 mm Hg saturated with vapor of the above mixture?

    a. 3.5%
    b. 4.5%
    c. 5.1%
    d. 9.9%


Question 2: Which one of the following health effects may be manifested by chronic overexposure to benzene?

    a. Bladder tumors
    b. Cholinesterase depression
    c. Abdominal colic
    d. Leukemogenic cancer


Question 3: What is the ACGIH Threshold Limit Value for fluoride primarily intended to guard against?
    a. delayed lung edema
    b. respiratory tract irritation
    c. tubular kidney injury
    d. mottling of tooth enamel


Question 4: Under usual operating conditions, what is the static pressure at the discharge side of a fan with 10' length of discharge duct?
    a. equal to the velocity pressure
    b. less than the atmospheric pressure
    c. equal to the total pressure
    d. greater than the atmospheric pressure


Question 5: 1,000 cfm is to be drawn into a round, freely suspended duct of 6" diameter. What is the expected centerline velocity at 4" outside the duct opening?
    a. 286 fpm
    b. 534 fpm
    c. 765 fpm
    d. 935 fpm


Question 6: Two separate noise sources of 98 dBA and 96 dBA respectively are installed and operated together. What is the combined noise level?
    a. 99 dBA
    b. 100 dBA
    c. 101 dBA
    d. 194 dBA


Question 7: A maintenance worker must enter an empty reactor vessel for cleaning, inspection and lining repair. In the absence of continuous ventilation and testing of the air in the vessel, what should an industrial hygienist recommend?
    a. an organic vapor respirator for the worker and a helper with a life line within earshot
    b. performance of the work at night with prior notice to the city's Emergency Response Unit
    c. flushing the tank with a suitable organic solvent before the worker enters
    d. a SCBA and fixed life line for the worker and a helper directly outside the tank


Question 8: Workers in a brass foundry complain of a fever and general malaise on Mondays following a weekend respite from work. What should an industrial hygienist be equipped to obtain, upon arrival at the foundry?
    a. blood samples to detect carbon monoxide exposures
    b. air samples to measure exposures to zinc fume
    c. potable water samples to detect PCB concentration
    d. urine samples to measure exposures to lead


Question 9: What do the radioisotopes 238U, 40K, 226Ra, and 235U have in common?
    a. Each is an alpha emitter.
    b. Each is a neutron emitter.
    c. Each occurs in nature.
    d. Each has an analogue normally found in the human body.


Question 10: Why is stack sampling for particulate aerosols done in an isokinetic manner?
    a. to avoid size discrimination of collected particles
    b. to minimize particle deposition in the sampling tube
    c. to collect the respirable size particles only
    d. to collect samples suitable for direct analysis


Question 11: Theoretically, what is the minimum number of sound pressure level measurements needed to determine the sound power output from a non-directional noise source in a free field?
    a. one
    b. two
    c. four
    d. eight


Question 12: What are too many levels of management, chronic and recurring internal problems, and numerous meetings attended by many people typically symptoms of?
    a. poor communications
    b. lack of management training
    c. poor employee morale
    d. a flawed organizational structure