Review of Chemistry UNIT1: Safety in the chemical laboratory I.1 Emergency Equipment A. Fire Extinguishers Location: all the fire extinguishers in your laboratory; the closest fire extinguish
er outside the laboratory. When to use: If you doubt that the fire is small enough that a fire extinguisher will do the job. How to use: take the extinguisher to the location of the fire, grab the extinguisher by the handle and yank the safety pin out of the side the handle with a sharp pull. B. Fire Blanket Location: the location of the fire blanket in the lab. How to use: pull the cord at the bottom of the fire blanket “tube” to get the blanket out. When to use: a fire blanket can be used when a student’s clothing or hair catches fire; a fire blanket can be used to smother burning material on the floor or a bench. C. Eyewash fountain or eyewash station Location: The location of the eyewash fountain or eyewash station. When to use: the eyewash must be used any tome a chemical or solution gets into eyes. How to use: use of an Eyewash Fountain; use of an Eyewash Bottle D. Emergency shower Location: the location of the emergency shower When to use: the shower is used when hazardous chemicals spray over large areas of the body. How to use: one involves an overhead shower having a pull-ring, while the other is a hand-held shower with an on-off handle E. Acid-base neutralizing solution Location: the location of the neutralizing solution When to use: use this solution whenever an acidic or basic (“caustic”) solution has come in contact with your skin. How to use: first wash the affected area with large amounts of water and then pour some of the neutralizing solution on the affected area and gently wash the skin with the solution. I.2 Protective Equipment A. Safety goggles Location: the safety goggles are stored. When to use: safety goggles must be used whenever chemicals are being used or glass-working is being performed. How to use: goggles must fit snugly B. Fume hoods Location: the location of the fume hoods. When to use: the fume hoods must be used whenever poisonous or offensive odorous are being produced. How to use: learn where the On/Off buttons for the fume hood are located (they generally are below or beside the fume hoods.) I.3 In case or fire a) The first and most important thing to do is to back out of harm’s way and evaluate the situation.
b) Next, warn the teacher and other students with a shout c) CONTROLLED FIRES: if a fire is controlled, in the sense that it is contained in a breaker, flask or test tube, the fire can often be put out by placing a watch glass or inverted beaker over the top of the container and smothering the fire. d) UNCONTROLLED FIRES: of the fire is not minor and will possibly continue to spread, everyone must immediately the room except those who may be using a fire extinguisher. I.4 Some Laboratory Hazards HAZARD Spilled chemicals NATURE OF HAZARD Chemical burns HOW TO DEAL WITH HAZARD Notify teacher for cleanup instructions, but keep away in the meantime. Notify teacher for cleanup instructions if chemicals are mixed with the glass. Step back and notify class, then deal with the fire as outlined above. Wash off immediately under fast-running water. Holding the container in front of you, dilute the smell by gently “wafting” the odor to your nose with a wave of the hand over the container and toward the nose. Tie long hair back or use elastics Tie long hair back or use elastics
Cuts; chemicals in cuts
Burning chemicals in container
Chemicals on hands Being asked to smell chemical vapors
Chemical burns; skin irritation or allergic reaction Strong odors may injure nasal passages
Bunsen burners Loose hair or “floppy” clothing/accessories
Burns; fires Burns or chemical spillage; equipment knocked onto floor
I.5. Disposal of Chemicals 1. Disposal of Unused Chemical 2. Disposal of Used Chemical I.6 General Rules of safe laboratory conduct 1. There must be no horseplay in the lab. 2. There must be no running in the lab. 3. You must not carry out unauthorized experiments. UNIT2: introduction to chemistry II. 1 Unit Conversion Avoid the temptation to solve the problems by your own method; you should learn the Unit Conversion method. How to put everything together (UNKNOWN AMOUT)= (INITIAL AMOUNT) x (CONVERSION FACTOR) Summary of the procedure to be used with unit conversions 1. Identify the unknown amount and its unit. 2. Identify the initial amount and its unit. 3. Identify the conversion factor.
4. Complete the problem by multiplying and/or dividing the amounts on the right-hand side. MULTIPLE UNIT CONVERSIONS II.2 SI Units A. Some selected base unit the international system (SI) Quantity Length Mass Time Amount of substance Written Unit Meter Gram* Second Mole Unit Symbol M G* S mol
※ The actual base unit for mass in the SI system is the kilogram (kg), which is an inconsistent base unit, but for the purposes of Chemistry 11 the gram (g) is considered to be the base unit. B. Some additional units used Quantity Volume mass C. Multiples of base units Written Prefix Mega Kilo Deci Centi Milli Micro D. Some important equivalence 1mL=1cm3 1m3=103L Written Prefix Yotta Zetta Exa Peta Tera Giga Hecto Deka Nano Pico Femto Atto Zepto yocto Prefix Symbol M K D C M u 1t=103kg Prefix symbol Y Z E P T G h Da n p f a z y Equivalent exponential 1024 1021 1018 1015 1012 109 102 101 10-9 10-12 10-15 10-18 10-21 10-24 Equivalent exponential 106 103 10-1 10-2 10-3 10-6 Written unit Liter Tonne Unit Symbol L t
II.3 Metric conversions Metric conversion involves using unit conversions between prefix symbols and exponential
equivalent. The diagram below shows the manner in which a given base unit (for example, meters) is related to the important prefix symbols. Mm