Question

Which of the following is not a laboratory safety rule?
A.You should never mix acids with bases
B.You should tie back your long hair
C.You should never add water to acids
D.All the above are valid safety rules

Answer 1

Hint:While working in a chemistry laboratory, the student is required to perform tidily and systematically. For this it is essential that he / she should follow the rules. The first and foremost concern in any chemical laboratory is the safety of those working in the laboratory. Because most of the chemicals are potentially dangerous in one way or the other and chemistry laboratories are a place where accidents can occur.
By adopting certain basic safety measures and showing alertness , and presence of mind most accidents in the chemistry laboratory can be avoided. It is important to remember that an individual's safety in a laboratory is affected not only by his own action but also by the action of his / her fellow workers.

Complete answer:
Some of the general guidelines on safety work practices are to be followed in a laboratory is given below
1.Always maintain strict discipline in the laboratory.
2.Do not eat , drink or smoke in the laboratory.
3.Try to be fully aware of what is going on elsewhere or around you in the laboratory.
4.Know the location of the alarm and fire extinguishers, also how to operate them.
5.Never work alone in the laboratory. If you are working alone then make someone aware of your location.
6.Do not use cracked or broken glassware. check glassware before using it.
7.Wear protective clothing (coat) ,safety glasses or goggles all the time. Girls should tie back their long hair.
8.Handle all the chemicals with care and read the labels before using it.
9.Do not touch any chemicals with your hands, always use gloves.
10.Avoid inhalation of gases or fumes.
11.Do not taste any chemicals
12.Do not add water to acids. Add acids slowly to the water with constant stirring.
13.While heating a test tube make sure that its mouth point is away from yourself and anyone else. Also note that never look directly into the mouth of the flask during the reaction .
14.Turn off all burners and electrical equipment when not in use.
15.Clean the work area and all the apparatus before leaving the laboratory also do not forget to wash your hands .
16.In the above safety rules it is not written that “do not mix acids with bases” . Because for carrying out many chemical reactions we have to mix the acids and bases.

So, here the one which is not a safety rule is option A.

Note:
Before performing any experiments in the laboratory you should have a thorough understanding of what you are going to do and what you are required to observe in that experiment. So you should carefully follow the instructions of your guide /teacher . Report all the accidents and injuries even if it is small , so that first aid can be applied immediately.