Ring Stand

Place a clean 250-mL beaker on the base of the ring stand. Attach the ring to the... 

Set up a ring stand and attach the ring to the stand. Place the wire gauze on the ring to provide a platform on which to place the beaker of water. 

Place the beaker on the hot plate, and insert the thermometer into the ice-water mixture. Clamp the thermometer to the ring stand so that the thermometer does not touch the side or bottom of the beaker. 

Clamp the test tube to the ring stand in the water bath. 

Use a ring stand and clamp to suspend the assembled dropping bottle in a 1000-mL beaker that is placed on a hot plate, as shown in Figure A. 

Raise the large can off the base of the ring stand and insert the four nuts evenly spaced under the can. This will allow air needed for the combustion of the candle to enter around the base of the can. 

Attach a ring to a ring stand and place a wire gauze on the ring. Place the evaporating dish on the wire gauze. 

Submerse the electrodes in the beaker of water and clamp them in position using a ring stand and two clamps. 

How can you make a polyester and a polyamide Objectives Prepare a polyester from phthalic anhydride and ethylene glycol. Prepare a polyamide from adipoyl chloride and hexamethylenediamine. phthalic anhydride (2.0 g) sodium acetate (0.1 g) ethylene glycol (1 mL) 5% adipoyl chloride in cyclohexane (25 mL) 50% aqueous ethanol (10 mL) 5% aqueous solution of hexamethylenediamine (25 mL) 20% sodium hydroxide (NaOH) (1 mL) scissors copper wire test tube test-tube rack 10-mL graduated cylinder 50-mL graduated cylinder 150-mL beakers (2) ring stand clamp Bunsen burner striker or matches balance weighing papers (2)... 

Clamp the test tube to a ring stand using a clamp and heat gently using a Bunsen burner until the mixture appears to boil. Continue to heat the mixture gently for 5 additional minutes. 

A funnel with a clamped rubber tube on the stem is placed in a ring stand. A circular mesh screen is placed across the funnel approximately one-third from the top, a portion of coarse fabric such as muslin is placed on the screen, and feces is added. Tap water at 37°C is added so that the water just touches the feces. Let the specimen stand 1 h, remove 2 ml of fluid from the stem, and centrifuge the sample at 300 x g for 3 min. Prepare a wet mount of sediment, and examine it for larvae. 

BASIN WASH 7QT STERILIZABLE PLASTIC FITS RING STAND 12S 6530014588301 PG 1.00 ... 

Working in a fume hood, heat cautiously with a Bunsen burner at first (lid slightly ajar) until the sample is thoroughly charred. Use the same ring stand apparatus as before. 

Assemble a filtration system consisting of a ring stand, a funnel rack (or two small rings), two clean long-stem funnels, and two beakers or flasks to catch the filtrate. Obtain two pieces of Whatman 40 filter paper, fold, and place into the funnels, moistening with a little distilled water so they adhere to the funnel walls (Figure 3.8). Label the funnels to coincide with the labels on your beakers. 

Assemble the apparatus for a titration. The buret should be a 50-mL buret and should be washed thoroughly with a buret brush and soapy water. Clamp the buret to a ring stand with either a buret clamp or an ordinary ring stand clamp. The receiving flask should be a 250-mL Erlenmeyer flask. You should clean and prepare three such flasks. Place a piece of white paper (a page from your notebook will do) on the base of the ring stand. This will help you see the end point better. 

Following this procedure, the funnel is positioned in a padded ring in a ring stand and left undisturbed for a period of time to allow the two immiscible layers to once again separate. The purpose of the specific design of the separatory funnel is mostly to provide for easy separation of the two immiscible liquid layers after the extraction takes place. All one needs to do is remove the stopper, open the stopcock, allow the bottom layer to drain, and then close the stopcock when the interface between the two layers disappears from sight in the stopcock. The denser of the two liquids is the bottom layer and will be drained through the stopcock first. The entire process may need to be repeated several times, since the... 

FIGURE 11.2 A drawing of a separatory funnel, containing two immiscible liquids, held in an iron ring clamped to a ring stand. 

Use the ring stand, small iron ring, funnel, Erlenmeyer flask, and filter paper to set up a filtration apparatus. Attach the iron ring to the ring stand. Adjust the height of the ring so the end of the funnel is inside the neck of the Erlenmeyer flask. 

For each group) ring stand with clamp... 

Arrange the ring on the ring stand so that it is about 7 cm above the top of the Bunsen burner. Place the clay triangle on the ring. 

Bunsen burner ring stand and ring crucible and lid clay triangle crucible tongs balance... 

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