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Laboratory Apparatus and Uses

• Beakers serve as reaction containers or to hold liquid, solid samples, or chemicals.
• They also collect liquids during titrations and filtrates.
• Bunsen burners are specially prepared burners using natural gas as fuel for burning.
• Bunsen burners heat various chemicals and solutions.
• Reagent bottles store liquid reagents.
• Crucibles are cup-shaped equipment used to contain chemical compounds heated to extremely high temperatures.
• Crucibles have lids to prevent substances from escaping or to keep oxygen out of reactions.
• Crucibles take and handle small quantities of solid chemicals.
• Wash bottles dispense small quantities of distilled water.
• Volumetric flasks measure precise volumes of liquid or to make precise dilutions.
• Tripod stands are used to support containers, especially when heating them above a Bunsen burner.
• Retort stands with clamps hold pieces of glassware in place.
• Test tube racks hold test tubes containing chemicals.
• Test tube holders hold test tubes when the tubes should not be touched.
• Safety goggles protect the eyes in the laboratory.
• Wire gauze spreads heat from a burner flame and supports beakers heated by Bunsen burners.
• Round-bottomed flasks are used to carry out reactions at high temperatures.
• Flat-bottomed flasks store solutions and carry out reactions at room temperature.
• Funnels transfer solids and liquids without spilling and are used for fitering with filter paper.
• Burettes dispense known amounts of a liquid reagent in experiments requiring precision, like titration experiments.
• Pipettes transport a measured volume of liquid and exist in different types like glass and piston-driven pipettes.
• Pasteur pipettes (teat pipettes or droppers) are made of plastic/glass, transfer small liquid amounts, and aren't graduated/calibrated.
• Pasteur pipettes are used for adding liquids drop by drop.
• Erlenmeyer flasks are used in chemistry, often for titrations, and to heat liquids.
• Erlenmeyer flasks are usually graduated on the side to indicate volume.
• The conical shape allows contents to be swirled/stirred, while the narrow neck prevents spillage.
• Cuvettes are small tubes with circular or square cross sections, sealed at one end, made of plastic, glass, or fused quartz (for ultraviolet light), and designed to hold samples for spectroscopic experiments.
• Measuring cylinders are laboratory glassware that take approximate measurements of liquids and measure volumes of objects by water displacement.
• Mortars and pestles grind and mix substances, including chemicals.
• The pestle is a heavy stick while the mortar is a bowl, often made from porcelain, wood, carved stone, or other materials.

Hazard Symbols

• Hazard symbols warn about hazardous materials.
• An oxidizing substance provides oxygen and allows other materials to burn more fiercely
• A flammable substance catches fire easily
• The skull-and-crossbones symbol denotes danger, usually for poisonous materials that can cause death if swallowed, breathed in, or absorbed.
• Harmful substances are similar to toxic substances but are less harmful.
• Corrosive substances destroy living tissues, including eyes and skin; wash affected areas with clean water.
• Irritant substances are non-corrosive but can cause reddening or blistering of skin.
• The radioactive symbol indicates substances with hazardous quantities of radioactive materials.

Units of Measurement

• Systems of measurement must be defined for people to agree on quantitative observations.
• The Système International (SI) system, also known as the metric system, is used by scientists.
• Mass is measured in kilograms (kg)
• Length in meters (m)
• Time in seconds (s)
• Temperature in Kelvin (K)
• Electric current in amperes (A)
• Amount of substance in moles (mol)
• Luminous intensity in candelas (cd).
• Prefixes are used to change the size of fundamental units.

Safety Rules - General

• Eating, drinking, or smoking is prohibited in the laboratory.
• Work areas should be kept clean, tidy, and free of clutter.
• Benches should be kept tidy.
• Solids should not put solids in sinks to avoid blockage.
• Cylinder valves should always be closed after use.
• Containers should always be labeled in plain English.
• Containers should be labelled with the known name of the substance and the appropriate hazard warning symbol.
• Reagent bottles should be secured with their respective tops immediately after use.
• Never use bare hands to transfer chemicals; use a spatula instead.
• Never smell gases directly.
• Instead fan a little of the gas towards the nose
• Concentrated acids and alkalis should always be handled with great care.
• Don't haphazardly mix chemicals.
• Pay attention to the order in which chemicals are to be added to each other and do not deviate from the instructions.

Safety Rules - Hygiene

• Always read the label making sure it is what you are looking for then put the bottle back.
• Fume cupboard sashes should be as low as possible and work towards the back of the cupboard.
• All spillages should be cleared immediately .
• Water hoses should be secured with jubilee clips.
• Pipetting by mouth is prohibited.
• Hands should always be washed after using substances hazardous to health, before leaving the laboratory, and before visiting the toilet.
• Surfaces should not be touched (phones, door handles, etc.) with contaminated gloves.

Handling Chemicals Safely

• Work with small containers.
• Mix chemicals only when instructed by the teacher.
• Read and reread chemical labels and instructions thoroughly before beginning.
• A work tray should be used.
• Move carefully and deliberately when handling chemicals.
• Always add concentrated sulfuric or phosphoric acid to water.
• The coin-top stoppers should be held between fingers while pouring.
• Hold bottles with the hand over the label.
• Replace stoppers immediately.
• Keep chemicals away from your face.
• Work with harmful volatile chemicals should be done in a hood.
• Chemicals should be kept pure and uncontaminated.
• Chemicals should be drawn with a pipette filter, never by mouth.
• Inform your teacher to clean up spills.
• Waste should be put in the proper container.
• Clean up your work bench when finished

Thermometer Safety

• Do not shake thermometers.
• Use thermometers only in the range they're suited for.
• Lay thermometers down on a
• Lay thermometers down on a towel or wire screen to cool, away from the edge of the bench.
• The teacher should clean up broken thermometers.

Glass Tubing Safety

• Use an inserter to place glass tubing in a stopper or remove it.
• Lubricate the tubing and protect your hands with leather gloves.

Centrifuge Safety

• Place equally filled test tubes in a centrifuge to balance it.
• Do not try to stop the spinning with your hand.

Dressing For Safety

• Do not wear extremely loose clothing.
• Fabrics should be sturdy and natural.
• Wear older clothes and cover them with a lab apron.
• Wear long pants or long skirts to cover your legs
• Wear closed leather shoes to protect your feet.
• Tie up long hair.
• Remove rings and watches.
• Take out contact lenses.
• Cover your eyes with goggles with side shields.
• Protect your hands with the right kind of gloves.

Laboratory Behavior

• Do not fool around in lab.
• Keep aisles clear of personal belongings.
• Stand on a step stool when you have to reach.
• Keep makeup in your purse.
• Keep food and drinks outside

Bunsen Burner and Glassware Safety

• Heat volatile organics in a heating hood.
• Always check the gas hose for cracks.
• Make sure the hose fits securely on the gas valve and Bunsen burner fittings.
• Stand back from the burner while lighting it.
• Strike matches away from you.
• Turn on the gas after lighting the match.
• Turn the gas off immediately if the flame sputters, flares, goes out, or if you smell gas.
• Check glassware for stars or cracks.
• Clamp narrow-necked containers to the ring stand.
• Move test tubes back and forth through the flame at the angle while heating.
• Do not heat closed containers.
• Hold hot glassware in beaker tongs or hot mitt.

Emergency Equipment

• Clean and dry the skin around a cut before a bandage is applied.
• Rinse chemicals from your eyes in the eyewash fountain.
• Rinse chemicals from your hands and arms with water in the sink.
• Remove your clothes on the way to safety shower to rinse large spills from your body.
• Extinguish small fires in containers by covering them.
• Let your teacher use an extinguisher to put out large fires.
• Put out clothing fires in the safety shower.
• If there's no other way to put out a clothing fire, use a fire blanket keeping flames away from the face and neck.
• Students must know the location of each piece of safety Students must know the location of each piece of safety equipment in the lab as following:
• SAFETY SHOWER; activate and know how to shut off the water.
• WORK TRAY; Spill water on the tray to see how this contains spill.
• EYEWASH; Push the bar or lever on the eyewash fountain
• FIRE EXTINGUISHER Stress that only you may use the fire extinguisher if needed and know how to use it.
• FIRE BLANKET; show demonstrably by pulling the blanket from out of its box and covering a prone body.

Measurement and Density

• Density is the ratio of mass to volume and uses dimensions like lb/ft³ or g/cm³ (g/mL).
• Density, as a characteristic physical property, is useful in identifying substances when recorded at specific temperatures and atmospheric pressures.
• General chemistry labs determine density using the mass and volume of a substance.
• Weighing a sample on a balance easily accomplishes finding mass
• Volume determination is not always straightforward, so methods depend on the nature of the sample.
• For regular shapes, dimensions are measured to calculate volume using equations
• Using (V = s³ for a cube and V = nr²h for a volume of the water displaced from Archimedes' Principle,
• The liquid displaced equals the volume of the displacing object)
• For small particles, liquid is added to the sample to obtain a reading from the calibration marks.
• To read small particles accurately the volume such granular as a sample, stir to mix the solid and the liquid and read the calibration marks to avoid errant amounts of space between particles.
• Granular volume is the the volume of (liquid + solid) subtracted by the liquid alone.

Hydrates

• Hydrates are compounds that hold water molecules in their solid structure that contains a number of water molecules associated with each formula unit of primary material.
• The water located within a hydrate is referred to as water of hydration, which is removed through heating and what is left after is called anhydrate or anhydrous.
• Hydrate formulas show fixed water content in their crystals
• Calcium chloride shows 4 water molecules with each formula unit of calcium chloride named Calcium chloride tetrahydrate
• Copper (II) sulfate shows presence of contains 5 molecules of water for each mole of copper (II) sulfate named copper (II) sulfate pentahydrate,
• Cobalt (II) chloride for example forms a red hydrate named cobalt (II) chloride hexahydrate and a violet hydrate named cobalt (II) chloride dihydrate.
• The mole ratio of water to salt is revealed in their names.
• Hydrates will lose water when heated strongly leaving behind a (water- free) salt, displaying a color change as water is lost
• Water loss by a hydrate is reversible if anhydrous salt is exposed to moist air and can distinguish from other compounds when heated or reformed using anhydrous salt
• General formula (salt.xH2O) is used to determine the percent water in a hydrate mass with formula and value in x to complete the compound
• The percent water by mass in a hydrate is by mass lost (by dividing the mass lost by the hydrate with heating by the mass of the original sample is determined in a hydrate) using (mass of hydrate sample with crucible is unknown minus mass of crucible with lid)
• Water driven off is determined by (mass of crucible/ unknown minus mass of crucible and residue after final heating)
• Using formula: divide mass of water driven off by mass of hydrate sample and X by 100% to get percent mass of hydrate.

Gravimetric Analysis

• Gravimetric analysis uses that processing of producing and weighing of an element that is pure as possible after some chemical treatment of the substance.
• The mass element and ion can be known using the formula, element of the compound and relative masses that deals in the measurement of mass within a chemical conversion.
• The amount of acid is obtained by a equation produced during the BaSO4 reaction

Volumetric Analysis (Titrimetric Analysis)

• It is the name for a technique that determines concentration of the by measuring the amount of solutions available.
• Achieved by chemical reaction of mixing a solution to another until the chemical is mixed in and completes titration with conical flask.
• Indicator added- an compound detects point where too much is made.
• Standard flask is used.
• Pipette delivers an amount of liquid to to fill it
• Burette uses tap water to measure liquids within.