Illustrated Guide to Home Chemistry Experiments

Chapter 18 Laboratory: Colloids and Suspensions 325

FIGURE 18-2: Homemade firefighting foam

CUTIOA nS

Although none of the chemicals used in this laboratory

session are ordinarily considered hazardous, it’s always

good practice to wear splash goggles, heavy-duty gloves,

and protective clothing.

z

dISoALp S : All waste solutions from this lab can be

flushed down the drain with plenty of water.

RQEWEvI UESTIOnS

q 1 : Why are foams like this particularly effective at putting out fires?

q: 2 Would a foam of carbon dioxide dispersed in water be a good choice for putting out burning sodium metal? Why or why not?

q: 3 Old-style soda-acid fire extinguishers produce not a stream of foam, but a stream of liquid. Propose an explanation.