Some Common Laboratory Glassware Please be careful when using glassware in the laboratory. Wet glassware and wet gloves are slippery. Always read a volume at the bottom of the meniscus. The meniscus should be at eye level to avoid parallax error. See Figure 1.3 on page 7 of the lab manual (13 th ed.) CHE116/CHE1181

Beaker Beakers come in different sizes. The total volume of the beaker is written on the outside. Some beakers have graduation marks on them. These graduated volumes are approximate volumes only. When an experimental procedure states that an approximate volume of liquid is needed, a beaker can be used to measure the volume. CHE116/CHE1182

Pipet The pipet is used to deliver an exact volume of liquid. Pipets handle aqueous solutions well. Pipets do not handle thick, viscous liquids well. They do not handle volatile organic liquids well. TC – to contain: All of the liquid inside the pipet is transferred to the receiving vessel (including the last drop). TD – to deliver: The liquid in the pipet is drained into the receiving vessel, the last drop remains inside the pipet. Pipet Pipetter Pipet NEVER PIPET BY MOUTH ! CHE116/CHE1183

Volumetric Flask The volumetric flask is used to measure an exact volume of liquid inside of the flask. Each volumetric flask has its own unique calibration mark on the narrow neck. The flask is filled to an exact volume when the bottom of the meniscus sits exactly on the graduation mark. The part of the flask where the narrow neck meets the bulb is fragile. Always hold the flask by the bulb part, especially when there is liquid in the flask. Graduation MarkFragile CHE116/CHE1184

Buret The buret is used to deliver an exact volume of liquid. The volume is read to 2 digits after the decimal place (example: mL) The calibration numbers seem upside down; 0.00 mL is at the top, and mL is at the bottom of the calibration range. Be careful reading the volumes. Never let the liquid get outside of the calibration range while measuring a volume. Buret Buret Clamp CHE116/CHE1185

Erlenmeyer Flask The Erlenmeyer flask is used to hold liquids. Its narrow mouth and sloped sides help keep liquid from splashing outside of the flask. The graduation marks on the flask are approximate. The Erlenmeyer flask cannot be used to measure out exact volumes of liquid CHE116/CHE1186

Graduated Cylinder The graduated cylinder is used to measure and dispense known volumes of liquids. The number of significant figures to use for a volume reading depends on the graduated cylinder and its calibration marks. Always read the volume at the bottom of the meniscus; have the meniscus at eye level. CHE116/CHE1187