Page 90 - 6641

Mix the contents of the test tube with a glass rod until the
paper is completely dissolved. Half of the solution is
poured into water. In this case, a precipitate of
unhydrolyzed cellulose falls.
The second part of the solution is placed in a glass of
boiling water and heated for several minutes before the
mixture is cooled. After cooling the solution pour into a
glass with 4-5 times the amount of water. The sediment
does not fall. After neutralizing the solution with a 10%
solution of sodium hydroxide (according to the universal
indicator), add a feling fluid and observe a reaction typical
of glucose.

Record the equation of the corresponding
reactions.

Dissolution of fiber in a solution of Schweitzer
reagent
3
Pour 2 sm of Schweizer's Reagent solution into a test
tube, add a piece of cotton wool and mix it with a glass rod
until the formation of a dark-blue syrupy mass. In this case,
complex compounds are formed. To the solution obtained
add 10% solution of sulfate acid drops.

Study of the properties of surfactants

3
In one test tube pour 2 sm of soap solution in water -
sodium salts of higher carboxylic acids (for example,
3
C 17H 35COONa), in another - 2 sm of detergent - a mixture
of sodium salts of higher sulfoacids (for example,
C1 3H 27OSO 3Na). The contents of the samples are divided
into two parts. Add to one part 2-3 drops of alcoholic
solution of phenolphthalein. What is observed? To the
3
second part add on 1 cm 10% solution of CaCl 2 and