Illustrated Guide to Home Chemistry Experiments

322 DIY Science: Illustrated Guide to Home Chemistry Experiments

RQEWEvI UESTIOnS

q 1 : What observable physical characteristic allows you to discriminate a colloid from a suspension?

q: 2 What observable physical characteristic allows you to discriminate a solution from a colloid?

dISoALp S : All waste solutions from this lab can be

flushed down the drain with plenty of water.

SBSTITUTIU oNS ANd modIfICATIoNS (continued)

• You may substitute any clear, colorless soft drink for
  the club soda.


• You can produce starch water by boiling a small
  amount of macaroni or other pasta in 250 mL of water
  for several minutes. Decant the water into a clean
  beaker and allow it to cool before use. (Alternatively,
  you can just save the cooking water the next time
  you cook pasta; it will keep for at least a day or two if
  refrigerated.)


• You may substitute any similar powder for the talcum
  powder, such as foot powder or body powder.

TABLE 18-3: Observe some properties of colloids and suspensions—observed data

Sample Tyndall Effect?Separates on standing? Classification

A. Smoke in air yes / no yes / no solution / colloid / suspension

B. Salt in water yes / no yes / no solution / colloid / suspension

C. Carbon dioxide in water yes / no yes / no solution / colloid / suspension

D. Milk in water yes / no yes / no solution / colloid / suspension

E. Oil in water yes / no yes / no solution / colloid / suspension

F. Starch in water yes / no yes / no solution / colloid / suspension

G. Talcum powder in water yes / no yes / no solution / colloid / suspension