Chapter 4

Question 1

Hydrogen cyanide (HCN) — a colorless gas with a characteristic almond odor. __ times more toxic than CO, it is an asphyxiant and can be ab- sorbed through the skin. HCN is produced in the combustion of natural materials, such as wool and silk, which contain nitrogen. It is also produced when polyurethane foam and other plastics that contain urea burn. The concentrated bulk chemical is also used in electroplating.

Answer 1

20

Question 2

As mentioned earlier, stopping the flow of water from open sprinklers as soon as the fire is controlled also reduces secondary damage. In addition, some departments use only __ foot lengths of hose inside of buildings to reduce the number of couplings from which water may leak.

Answer 2

100

Question 3

In other situations, water absorbed by materials at the bottom of a tall stack can cause the entire stack to lose stability and topple over. If the stacked materials happen to be rolls of newsprint that can weigh more than __ pounds each, such a collapse could be lethal for firefighters nearby

Answer 3

2,500

Question 4

Absorbed water, and that accumulating on the floor, can add a tremendous amount of weight to a structure. For example, a building measuring 50×100 feet with an accumulation of water 6 inches deep on an upper floor requires the structure to support an additional __ tons of weight.

Answer 4

78