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 best for measuring exactly 25.00 mL of ethanol as it is designed for delivering a single, fixed - volume with high precision.
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 smaller uncertainties and is designed for accurate volume measurements, while beakers and Erlenmeyer flasks are for general - purpose use and have larger measurement errors.
4. Borosilicate glass (Pyrex) has low thermal expansion, high chemical resistance, and can withstand temperature changes and chemical attacks well, making it suitable for organic chemistry work.
5. In distillation, properly assembled and clean glassware ensures accurate separation, prevents contamination of the distillate, and avoids leaks that could lead to loss of product or safety hazards.

Answer:

1. A volumetric pipette because it is designed for delivering a specific, accurate volume.
2. It can leak, break further, cause injury, or contaminate reactions.
3. They have more precise calibration marks and are designed for accurate volume measurements.
4. It has low thermal expansion and high chemical resistance.
5. To ensure accurate separation, prevent contamination, and avoid leaks.