Presentation on theme: "1 Physical (heat, noise radiation) Chemical (inhalation or skin contact with chemicals) Biological (Due to exposure to bacteria, viruses, and parasites."— Presentation transcript:
Physical (heat, noise radiation) Chemical (inhalation or skin contact with chemicals) Biological (Due to exposure to bacteria, viruses, and parasites and their entrance to the body via injures) Mechanical (operation of instruments and equipments) Psychological and social (any unfavourable conditions in the university environment) 2
15 Safety items in the laboratory: Locate and read the instructions on: a. Fire extinguisher b. First aid kit
Wear your lab coat once you entered the lab Keep your working area of the bench tidy Read labels carefully Strong acids and alkali shouldn’t be washed down the sink Label all test tubes and flasks clearly and properly When heating a test tube, point the mouth of the tube away from yourself and from others 16
Do not eat or drink in the lab Clear up the working area at the end of each lab Wash your hands with soap and disinfectant before leaving the lab Never remove chemicals from the lab 17
Report all accidents and injuries to your instructor immediately Long hair must be tied back during lab sessions Never mix chemicals together Never return excess reagents to the stock bottle 18
Rinse with tap water Scrub with detergent and a brush Rinse with tap water Rinse with distilled water Allow to dry in an inverted position 19
Do not use chipped or broken glassware Never carry large bottles by their neck Do not force stoppers too firmly into bottles dispose of broken glass using paper towels and gloves 20
Wear a protective goggle when working with corrosive reagents 21
GLOVES 22 Always wear a suitable pair of gloves when handling hazardous materials
LABORATORY EQUIPMENT Beam Balance Used to find the mass of various materials. Electronic Balance Used to find the mass of materials. This particular balance is not as precise as the beam balance.
Hot Plate Used for heating liquids. Gas Jet and Outlet The hose from the Bunsen burner connects to the jet. LABORATORY EQUIPMENT
Ring Stand Used in many lab activities as the support for other apparatus.
LABORATORY EQUIPMENT Typical Setup Ring stand shown with iron ring, wire gauze and a beaker. The Bunsen burner would go below the "stage". Clamp May be attached to a ring stand and be made to hold a test tube or thermometer.
Length - the distance between two points standard unit is meter (m) long distances are measured in km Measured using a meter stick or ruler
Mass is a measure of the amount of matter in an object. Mass does not depend on location. Weight is a measure of the gravitational force acting on an object. Weight depends on location. Chemist measure grams or milligrams
Converting Between Temperature Scales o F = (1.8 x o C) + 32 K = o C + 273.15
Mass is the amount of matter that makes up an object. A golf ball and a ping pong ball are the same size, but the golf ball has a lot more matter in it. So the golf ball will have more mass. The standard international (SI) unit for mass is the gram. The mass of an object will not change unless we add or subtract matter from it.
We will use a triple beam balance scale to measure mass. Gravity pulls equally on both sides of a balance scale, so you will get the same mass no matter what planet you are on.
Volume = length x width x height Units – m 3 Chemist tend to use milliliters (mL) or Liters (L)
The base unit for volume is the Liter. We measure volume with a graduated cylinder.
Liquids form curved, upper surfaces when poured into graduated cylinders To correctly read the volume, read the bottom of the curve called the meniscus
Volume - length x width x height V = 2.8 cm x 3.2 cm x 2.5 cm V = 22.4 cm3 Measured with a ruler
When the metric system was created, they decided that 1 cm 3 of water would equal 1 milliliter of water and the 1 mL of water will have a mass of one gram. 1cm 3 water =1 ml of water = 1 gram
1 cm 3 water = 1 mL of water = 1 gram So what would be the mass of 50 mL of water be? 50 grams So what would be the mass of 1 liter of water be? 1 L = 1000 mL so its mass would be 1000 grams or a kilogram.