5b (20)

Practicing

Test method:

The test is based on gravimetric measurements.

Equipment and Solutions (testing environment):

•    10 Steel specimens (dimensions 20 mm x 100 mm x 0,3 mm).

•    balance,

•    beakers (capacity 600 cm³),

•    wash bottle distillated,

•    a pair of tweezers, _{v c}

•    bowls for coilecting exuded liquid,

•    filter cones

•    acids: 1M HC1, 2M HC1, 1M H₂S0₄

•    base: saturated Ca(OH)2 (limę solution).

Test procedurę:

1.    Polish and clean the specimens using a piece of abrasive paper and sińce this moment don’t touch the samples - use only a pair of tweezers.

2.    Clean specimen in water and organie sołvent.

3.    Dry specimen precisely.

4.    Weight each of specimen exact to a 0,1 mg.

5.    Place into two beakers (about 600 cm³):

•    First - place 8 specimen (attention! Specimen can’t touch each other)

•    Second - place 2 specimen

6.    Pour Solutions:

•    First - acid

•    Second - base

7.    Write down the time beginning of experiments.

8.    Take specimen out of beakers:

•    First - 2 samples after 15 minutę, next after 30,45 and 60 minutes

•    Second - after 60 minutes.

9.    Clean samples in distilled water, dry and weight.

10.    Calculate average mass of every pair of samples (before and after experiments).

11.    Calculate the weight loss and corrosion ratę determination.

12.    Complete the table of data.

13.    Draw charts of W = f(T), CR = f(T).

14.    Draw conclusions.

How to get the credit:

1.    Participation in the lab classes.

2.    Positive notę from the test.

3.    Credit for report