Using the Laboratory Pipette

Laboratory Equipment and Usage

• Funnel: Channels liquids or fine-grained substances into containers with a small opening.
• Graduated Cylinder: Measures liquid volumes, featuring marked lines for liquid level.
• Iron Clamp: Secures utility clamps to support stands; can also clamp rods together.
• Iron Ring: Supports flasks or funnels upright for stability during experiments.
• Iron Stand (Ring Stand): Provides support for equipment and elevates it above the work surface.
• Mortar and Pestle: Grinds and mixes substances; pestle is a heavy tool used for pounding.
• Pipette (Chemical Dropper): Transfers measurable liquid amounts; available in volumetric and measuring types.
• Platform Balance: Weighs objects using counterweights on two platforms for balance.
• Thermometer: Measures temperature through various methods; includes alcohol, digital, and mercury types.
• Tripod: Supports various glassware during experiments and when not in use.
• Triple Beam Balance: Weighs samples using counterweights on three rider beams.
• Vials (Phial/Flacon): Small vessels for storing medications as liquids, powders, or capsules.
• Watch Glass: Circular glass for evaporating liquids, weighing solids, or covering beakers to prevent contamination.

Handling Solutions

• Transferring Solutions: Use a stirring rod to pour from a reagent bottle to an open container.
• Opening Reagent Bottle: Pull glass stopper gently with fingers, palm up.
• Using Laboratory Pipette:
  • Fill pipette using capillary action; use a finger to hold the liquid inside.
  • For precise amounts, use an aspirator to manage air and liquid flow.
  • Maintain a 45-degree angle while transferring liquids.

Handling Solids

• Retrieving Solids: Use a clean, dry spatula to avoid contamination.
• Weighing Solids: Place on watch glass, not directly on balance pans.
• Reagent Return Policy: Do not return excess reagents to prevent contamination.

Heating Solutions in a Test Tube

• Fill test tube to half and hold it with a test tube holder.
• Heat at a 45-degree angle, moving it back and forth over the flame.
• Avoid pointing the open end towards anyone and do not look directly inside the tube.
• Identify smell by waving hand towards the nose instead of smelling directly.

Measurements and Definitions

• Measurements of Length: Rulers and vernier calipers.
• Measurements of Volume: Beakers, graduated cylinders, pipettes.
• Density and Weight Measurement: Analytical balance, triple beam balance.
• Mass: Total matter in a body, regardless of volume or forces acting upon it.
• Meniscus: Curved upper surface of liquid in a tube.
• Density: Consistency measured by mass per unit volume.
• Volume: Space occupied by a substance.

Matter Classification

• States of Matter: Solid, liquid, gas.
• Pure Substances: Definite composition with unique properties; further classified into elements and compounds.
• Element: Simplest matter, classified into metals, non-metals, metalloids.
• Compound: Composed of two or more chemically united elements.
• Mixture: Contains two or more substances not chemically combined; categorized as homogeneous or heterogeneous.
• Homogeneous Mixture: Uniform appearance and composition, exists in one phase (e.g., solutions).
• Heterogeneous Mixture: Distinct portions can be mechanically separated, differing in properties and composition.

This quiz focuses on the proper techniques for using a laboratory pipette, including how to hold it and measure exact amounts of liquid. Learn essential skills for managing different solutions accurately using a pipette and aspirator. Test your knowledge on these vital procedures for lab work.