Question

guide questions: 1. which glassware would you select if an experiment requires measuring exactly 25.00 ml of ethanol? why? 2. why should chipped or cracked glassware never be used in organic experiments? 3. what makes volumetric glassware (pipette, burette, volumetric flask) more precise than a beaker or erlenmeyer flask? 4. why is borosilicate glass (pyrex) preferred in organic chemistry laboratories? 5. in distillation, why is it important to use properly assembled and clean glassware?

Explanation:

1. A volumetric pipette is ideal for measuring exactly 25.00 mL of ethanol as it is designed for delivering a single, precise volume.
2. Chipped or cracked glassware can leak chemicals, break further during use, and cause injury or contaminate reactions in organic experiments.
3. Volumetric glassware has calibration marks with high precision for accurate volume measurements, while beakers and Erlenmeyer flasks are for general - purpose use with less accuracy.
4. Borosilicate glass (Pyrex) has low thermal expansion, high chemical resistance, and can withstand temperature changes well, making it suitable for organic chemistry where temperature variations and chemical reactions are common.
5. In distillation, properly assembled and clean glassware ensures no leaks, accurate separation of components, and prevents contamination of the distillate.

Answer:

1. A volumetric pipette because it is designed for delivering a single, precise volume.
2. It can leak chemicals, break further, cause injury, or contaminate reactions.
3. They have calibration marks for high - precision volume measurements; beakers and Erlenmeyer flasks are for general use with less accuracy.
4. It has low thermal expansion, high chemical resistance, and can withstand temperature changes.
5. To ensure no leaks, accurate separation, and prevent distillate contamination.