What is this? 048

From approximately left to right:

• 3 test tubes
• 3 vials with plastic caps
• 3 Erlenmeyer flasks of different sizes
• Petri dish
• Graduated cylinder
• Plastic funnel
• A beaker containing 3 test tubes
• A brown dropper bottle with dropper lying next to it
• 2 more beakers
• 2 watch glasses
• Florence flask
• Plastic wash bottle
• 3 more test tubes

Laboratory glassware is made of borosilicate glass (Pyrex) which does not crack when heated

• The neck of an Erlenmeyer flask can be clamped to a ring stand
• Fluid in an Erlenmeyer flask can be mixed by swirling with less risk of spillage
• The sloped walls allow more vapor to condense and return to the sample while heating
• Similarly, the narrow mouth of the flask reduces the amount of evaporation while heating
• The narrow mouth and lack of a spout allows the flask to be sealed with a stopper

Measuring the volume of liquids

Measuring a very precise volume of a liquid. A volumetric flask can only measure one volume.

The brown color blocks light that might break down chemicals stored in the bottle.

Round-bottomed flasks are truly spherical and they will not stand upright without support. A Florence flask is mostly spherical but has a flat bottom so that it will stand up. Also, a round-bottomed flask typically has a ground glass joint which is used to connect other pieces of glassware, while a Florence flask does not.

It is made of plastic. Although plastic laboratory funnels exist, they are less inert and more difficult to clean than glass funnels.

A watch glass has many uses including:

• evaporating liquids
• holding a sample for weighing
• covering a beaker
• heating small samples

A petrie dish is usually used to grow cultures of cells or microorganisms and are unlikely to be found in an organic chemistry lab.

A Florence flask is used to boil liquids during chemical reactions and are unlikely to be found in a biology lab.

• Recognize laboratory equipment
• Understand the uses of laboratory equipment