Logged out
Access All our Essays in an Instant
Swap your work for FREE access, or pay £4.99 for instant access
Preparation of a crystalline derivative.
Member rating:
(2 votes)
| Words:
| Submitted: Mon Jun 06 2005
Page Preview
On the left is an image preview of every page of this document, and below are the first 150 words with formatting removed:
Preparation of a crystalline derivative. 1. Place 0.5 cm3 (10 drops) of the unknown liquid. (If the substance is solid dissolve 0.5g in a minimum amount of methanol.) Add 5 cm3 of the 2,4-dinitrophenylhydrazine solution and stir. 2. If precipitation does not occur, carefully add 1 cm3 of dilute sulphuric acid. 3. Using suction filtration apparatus as shown in diagram1, filter the precipitate. 4. Stop suction, either by lifting the funnel or by disconnecting the tubing, and soak the precipitate in about 1 cm3 of methanol. (Do not turn off the tap as you may get a "suck back" of water.) 5. Resume suction and dry the crystals by drawing air through them for a few minutes. 6. Recrystallize the solid using the following procedures. a. Transfer the crystals to a 150 cm3 beaker in a water bath. b. Dissolve the crystals in the minimum amount of hot ethanol. c. When the crystals have dissolved, cool the solution in...
Get instant access
- Instant, unlimited access to our documents in full
- Swap your work for free access, or pay £4.99
- To see the full version of this document and 149,488 others
