Question

1. describe the proper way of detecting the odor of a chemical substance. what is this technique called?
2. the university of california, berkeleys department of environmental health and safety notes that heat is released when strong acids are mixed with water. if you add water to acid, you form an extremely concentrated solution of acid initially and the solution may boil very violently, splashing concentrated acid. if you add acid to water, the solution that forms is very dilute and the small amount of heat released is not enough to vaporize and spatter it. when mixing strong acids with water, is it safer to add acid to water, or to add water to acid? explain your response in your own words.
3. how do you dispose of your chemical wastes at the end of a lab?
4. why is it against the chemical safety rules to return unused chemicals to their containers?
5. how do you determine if heated glassware is safe to touch?
6. what dress code rules should be obeyed when using an open flame?
7. how will you exit the room in case of fire?
8. what should you do if there is a fire on some materials at your lab station?
9. you were wearing goggles during the lab, but raised them up for just a second to rub your eyes. moments later, you start to notice that your eyes are watering and feel itchy and red. you must have had some chemicals on your hand, and now those chemicals are in your eye. describe in detail the steps you should take next.
10. oops - your wrist brushed against the surface of a hotplate, and you just got burned! you have a red welt across your wrist, it looks like a blister is forming., and it really, really hurts. describe in detail the steps you should take next.
11. you accidentally broke an empty test - tube while you were carrying your materials over to your lab station. describe in detail the steps you should take next.

Explanation:

1. The proper way to detect the odor of a chemical substance is called wafting. You gently wave your hand over the container to direct a small amount of the vapor towards your nose.
2. It is safer to add acid to water. When you add water to acid, a large amount of heat is released rapidly which can cause splashing and potential harm. Adding acid to water spreads the heat out more gradually.
3. Chemical wastes should be disposed of according to specific lab - waste disposal procedures. This usually involves using designated waste containers and following local regulations to prevent environmental contamination and ensure safety.
4. Returning unused chemicals to their containers is against safety rules because the unused chemicals may have been contaminated during the experiment, which could contaminate the entire stock of the chemical in the original container.
5. To determine if heated glassware is safe to touch, you can hold your hand close to the glassware (but not touching) to feel for heat. If you don't feel any heat radiating from it, it is likely safe to touch.
6. When using an open flame, long hair should be tied back, loose clothing should be avoided, and flammable materials should be kept away.
7. In case of a fire, you should follow the pre - established evacuation route, stay low to avoid smoke inhalation, and notify the appropriate authorities (such as the fire department) from a safe location.
8. If there is a fire at your lab station, first try to smother the fire with a fire blanket if it is small. If it is out of control, immediately evacuate the area and pull the fire alarm.
9. If chemicals get into your eyes, immediately flush your eyes with large amounts of running water for at least 15 minutes while keeping your eyes open and notify the instructor.
10. If you get burned, run cool (not cold) water over the burn for 10 - 15 minutes to reduce pain and swelling, then notify the instructor and seek further medical attention if necessary.
11. If you break an empty test - tube, carefully sweep up the broken pieces with a brush and dustpan and dispose of them in a designated glass - waste container, then notify the instructor.

Answer:

1. Wafting.
2. It is safer to add acid to water because adding water to acid can cause violent boiling and splashing due to rapid heat release.
3. Follow specific lab - waste disposal procedures, use designated waste containers.
4. Unused chemicals may be contaminated during the experiment and could contaminate the original stock.
5. Hold your hand close to the glassware (not touching) to feel for heat.
6. Tie back long hair, avoid loose clothing, keep flammable materials away.
7. Follow the pre - established evacuation route, stay low, notify authorities from a safe location.
8. Smother with a fire blanket if small, evacuate and pull the fire alarm if out of control.
9. Flush eyes with large amounts of running water for at least 15 minutes while keeping eyes open, notify the instructor.
10. Run cool water over the burn for 10 - 15 minutes, notify the instructor, seek further medical attention if needed.
11. Carefully sweep up broken pieces with a brush and dustpan, dispose of in a designated glass - waste container, notify the instructor.