Common First Aids Guide

Common First Aids

• Injuries: Cuts, Bruises
  • Do not touch an open wound without safety gloves.
  • Press directly on minor cuts to stop bleeding quickly.
  • Apply cold compresses to bruises to reduce swelling.

Broken Laboratory Glassware

• Alert the instructor immediately if glassware is broken.
• Do not touch broken glass.

Fainting

• Provide fresh air and have the person recline with their head lower than their body.

Poisoning

• Alert the instructor immediately.
• Find out what substance caused the poisoning.

Electrical Shock

• Alert the instructor immediately.
• Shut down the current at the source.
• Carefully remove wire using rubber gloves.

Spills on Skin

• Flush with large quantities of water.
  • Baking soda solution for acid spills.
  • Vinegar or boric acid for base spills.

Injuries to Eyes

• Immediately flush eyes with plenty of water for several minutes.
• Do not rub eyes if a foreign object is lodged in them.

Common Laboratory Glassware

• Pipettes
  • Disposable transfer pipette: Made of plastic; used to transfer liquids drop-wise.
  • Graduated pipettes: Have markings to measure liquid transfer volumes. Often used for transferring reagents or solvents for dilution.
  • Volumetric pipettes: Glass pipettes used to transfer highly accurate volumes of liquid. Common fixed volumes include 1 ml and 10 ml.
• Pipette Pumps: Used to aid in the use of pipettes. Different colors/types are available depending upon the purpose and quantity of liquid to be used.
• Graduated Cylinders, Beakers, Erlenmeyer Flasks: 
  • Graduated Cylinders: Used for transferring liquids with moderate accuracy.
  • Beakers: Used as general containers and come in many sizes. Volume markings may be rough approximations.
  • Erlenmeyer Flasks: Used as reaction vessels in titrations. Volume markings may not be a precise measure.
• Volumetric Flasks: Designed for precise measurement and storage of liquids and has a line indicating the exact volume.
• Burettes: Vertical cylindrical pieces of laboratory glassware; used to precisely dispense liquids in titrations. The measurements on the burette are taken from the top of liquid dispensed.
• Additional Equipment
  • Bunsen Burner
  • Funnels
  • Test tubes
  • Test tube racks
  • Test tube brush
  • Test tube holder
  • Clamp and clamp extension.

Weighing and Electronic Balance

• Mass determination requires a balance.
• Balances are precision instruments and quickly weigh objects.
• Most balances display mass directly on an LED display.
• Common balance types: 2-digit and 4-digit.

Determining Density of Substances

• Density is mass per unit volume of a substance.
• Objectives: Learn to use lab equipment and devices, determine density of water, and identify unknown substances using density comparisons.
• Units of density are kg/m³ or g/cm³, (g/mL).
• Procedure:
  1. Weigh a beaker accurately.
  2. Add 10 ml of a liquid to the beaker and re-weigh.
  3. Calculate weight of liquid.
  4. Calculate density (Weight of liquid/Volume)  
  5. Repeat for unknown substance.
• Calculations:  Calculate the density of the substance after finding its weight and volume
• Results: Compare the calculated density with standard densities to identify the substance.