Semimicroscale crystallization

EXPERIMENT 3A Semimicroscale Crystallization—Erlenmeyer Flask and Hirsch Funnel... 

This experiment assumes a familiarity with the general semimicroscale crystallization procedure (Technique 11, Section 11.3). In this experiment. Step 2 in Technique 11, Figure 11.3 (removal of insoluble impurities) will not be required. Although the impure sample may have a slight color, it will also not be necessary to use a decolorizing agent (Technique 11, Section 11.7). Leaving out these steps makes the crystallization easier to perform. Furthermore, very few experiments in... 

Follow the semimicroscale crystallization procedure described in Technique 11, Section 11.3, and shown in Figure 11.4. Step 2 in Figure 11.4 (removal of insoluble impurities) will not be required in this crystallization. 

Purify all of the crude chalcone from hot 95% ethanol or hot methanol using the semimicroscale crystallization procedure (Technique 11, Section 11.3). Alternatively, purify part of the chalcone using a Craig tube (Technique 8, Section 8.7, and Technique 11, Section 11.4), as follows ... 

The method described here for semimicroscale crystallizations is nearly identical to that used for crystallizing larger amounts of materials than those encountered in this textbook. Therefore, this technique can also be used to perform crystallizations at the macroscale level (more than several grams). 

Methods for removing insoluble impurities in a semimicroscale crystallization. 

Two procedures are given here for crystallizing sulfanilamide a semimicroscale procedure using an Erlenmeyer flask and a Hirsch funnel (Experiment 3A) and a microscale procedure with a Craig tube (Experiment 3B). Your instructor may assign both or just one of these procedures. 

The crystallization technique described in this section is used when the weight of solid to be crystallized is more than 0.1 g. The four main steps in a semimicroscale... 

The four steps in a semimicroscale or microscale crystallization are summarized in Table 11.1. 

Technique 2 Simple Distillation at the Semimicroscale Level (pp. 61-64) Technique 5 Crystallization... 

---