Common Chemistry Laboratory Equipment, Summaries of Earth science

Download Common Chemistry Laboratory Equipment and more Summaries Earth science in PDF only on Docsity! C O M M O N C H E M I S T R Y L A B O R A T O R Y E Q U I P M E N T Why should the spatula used for spooning solid chemicals from a reagent bottle be clean and dry? 1. - We use a clean, dry spatula to remove solids from the reagent bottle to avoid contaminating the portion removed and the remaining amount in the bottle. Using a dirty spatula is very restricted, especial ly when working on a sensit ive experiment or examination, to avoid chemical reactions that can cause an accident. 2. Why must f lat-topped stoppers be laid with their f lat sides on the table? -If we do not lay the stopper on its f lat side, there is a chance that it wil l rol l off the table and break. Properly putting flat-topped stoppers should be practiced to avoid contaminating the stopper with anything else on the table. 3. What is the use of the glass rod in transferring l iquid reagents? -When transferring l iquid from one vessel to another, the glass rod prevents spil ls and moves the l iquid to the receiving vessel without a backsplash. The glass rod acts as a channel to keep the solution from getting splashed around. 4. In heating l iquids in a test tube, why should the tube not be pointed to anyone while it is being heated? -When a test tube is being heated, it is dangerous to point it at someone because you could hurt yourself or someone else. Because if the experiment in the test tube is explosive or very reactive, it could spit out things that could harm your eyes or skin. If anything comes out of the test tube, it won't hurt anyone if you point it away. 5. When heating l iquids in a test tube, why is the test tube moved back and forth across the flame? -Consistent heating of test tubes often results in rapid local boil ing and consequent shooting out of the l iquid. To ensure that the l iquid is heated evenly, many people practice heating a test tube while moving it back and forth around a flame to ensure the l iquid heats up evenly and to get a smoother boil . By doing this practice, there is a tiny chance that concentrated heating may put stress on a weak spot in the glass and cause it to break. 6. What precaution should be fol lowed in preparing dilute acid solution? -When preparing dilute acid solutions, it is necessary to use the appropriate safety equipment. First, we must always begin by planning. To avoid being exposed to gaseous vapors, always wear goggles, gloves, an apron, or a lab coat, and work under a fume hood. Remember not to put water on the acid to avoid a vigorous exothermic reaction. C O M M O N C H E M I S T R Y L A B O R A T O R Y E Q U I P M E N T 7. Give at least f ive of the fol lowing: A . Draw five common laboratory equipment used in chemistry lab and l ist its uses BEAKER Used to hold and heat l iquids. Multipurpose and essential in the lab. GLASS FUNNEL Used to pour l iquids into any container so they wil l not be lost or spil led. They are also used with folded fi lter paper for f i ltration. ELECTRONIC BALANCE Used for weighing substances or objects, usually in grams. GLASS STIR ROD Used to stir l iquids. They are usually made of glass. ERLENMEYER FLASKS Used to heat, mix, and store l iquids. The advantage to the Erlenmeyer Flask is that the bottom is wider than the top so it wil l heat quicker because of the greater surface area exposed to the heat. Lab Safety Rules 1 . Never taste, smell or breathe any chemical 2. Wash your hands before leaving the lab and after any break or spil lage 3. Before beginning any experiments/tasks consult your lab handbook as well as other reference material for safety precautions 4. Always use personal protective equipment (gloves) when needed and never touch another persons protective equipment 5. Always have a base level of knowledge about the chemicals you are working with. B. Safety rules or precautions inside the chemistry laboratory