Difference between revisions of "rayon"

From Noah.org
Jump to navigationJump to search
m
m
 
Line 4: Line 4:
 
;copper(II) hydroxide (cupric hydroxide): Prepare by precipitating from aqueous solution of copper sulfate using sodium hydroxide or ammonia. Filter and wash with water until filtrate does not test positive for sulfate ions using barium chloride solution.
 
;copper(II) hydroxide (cupric hydroxide): Prepare by precipitating from aqueous solution of copper sulfate using sodium hydroxide or ammonia. Filter and wash with water until filtrate does not test positive for sulfate ions using barium chloride solution.
 
;barium chloride: observe toxic precautions. Used to test for sulfate. Any sulfate will precipitate out of a barium chloride solution as white barium sulfate.
 
;barium chloride: observe toxic precautions. Used to test for sulfate. Any sulfate will precipitate out of a barium chloride solution as white barium sulfate.
;sulfuric acid: H<sub>2</sub>SO<sub>4</sub>, one of our favorite strong mineral acids. When 98% pure it is called '''concentrated sulfuric acid''' or '''conc. sulfuric acid'''. Concentrated Sulfuric Acid has a density of 1840 g/l (1.84gm/ml) - it is '''much''' heavier than water. Trivia: it is diprotic, meaning it ionizes twice when dissolved in water (gives up 2 hydrogens). Beware when mixing with water because this reaction is exothermic.
+
;sulfuric acid: H<sub>2</sub>SO<sub>4</sub>, one of our favorite strong mineral acids. When 98% pure (18 M) it is called '''concentrated sulfuric acid''' or '''conc. sulfuric acid'''. Concentrated Sulfuric Acid has a density of 1840 g/l (1.84gm/ml) - it is '''much''' heavier than water. Trivia: it is diprotic, meaning it ionizes twice when dissolved in water (gives up 2 hydrogens). Beware when mixing with water because this reaction is exothermic.
;4M sulfuric acid solution (battery acid): 33.52% aqueous sulfuric acid. One mole of H<sub>2</sub>SO<sub>4</sub> weighs 98.07 g, so 335 g (183 ml) of concentrated H<sub>2</sub>SO<sub>4</sub> is added to 665 ml (665 g) of water.
+
;6M sulfuric acid solution (battery acid 5.2M to 6 M): One mole of H<sub>2</sub>SO<sub>4</sub> weighs 98.07 g, so 321 mL (588 g) of concentrated H<sub>2</sub>SO<sub>4</sub> is added to 679 mL (679 g) of water.
 
;3M sulfuric acid solution: One mole of H<sub>2</sub>SO<sub>4</sub> weighs 98.07 g, so 294.21 g of H<sub>2</sub>SO<sub>4</sub> is added to 750 ml of water. More water is added until the total volume is 1 liter. This is done like this to avoid adding water to sulfuric acid.
 
;3M sulfuric acid solution: One mole of H<sub>2</sub>SO<sub>4</sub> weighs 98.07 g, so 294.21 g of H<sub>2</sub>SO<sub>4</sub> is added to 750 ml of water. More water is added until the total volume is 1 liter. This is done like this to avoid adding water to sulfuric acid.
 
50 ml of distilled water, add 20 ml concentrated H2SO4. Exothermic, so proceed slowly. Vessel should be cooled in ice bath.
 
50 ml of distilled water, add 20 ml concentrated H2SO4. Exothermic, so proceed slowly. Vessel should be cooled in ice bath.

Latest revision as of 00:34, 7 October 2014


Schweizer's reagent
tetra-ammine cupric hydroxide, chemical complex tetraamminediaquacopper dihydroxide, [Cu(NH3)4(H2O)2]2+]]. Prepare by dissolving copper(II) hydroxide in solution of ammonia.
copper(II) hydroxide (cupric hydroxide)
Prepare by precipitating from aqueous solution of copper sulfate using sodium hydroxide or ammonia. Filter and wash with water until filtrate does not test positive for sulfate ions using barium chloride solution.
barium chloride
observe toxic precautions. Used to test for sulfate. Any sulfate will precipitate out of a barium chloride solution as white barium sulfate.
sulfuric acid
H2SO4, one of our favorite strong mineral acids. When 98% pure (18 M) it is called concentrated sulfuric acid or conc. sulfuric acid. Concentrated Sulfuric Acid has a density of 1840 g/l (1.84gm/ml) - it is much heavier than water. Trivia: it is diprotic, meaning it ionizes twice when dissolved in water (gives up 2 hydrogens). Beware when mixing with water because this reaction is exothermic.
6M sulfuric acid solution (battery acid 5.2M to 6 M)
One mole of H2SO4 weighs 98.07 g, so 321 mL (588 g) of concentrated H2SO4 is added to 679 mL (679 g) of water.
3M sulfuric acid solution
One mole of H2SO4 weighs 98.07 g, so 294.21 g of H2SO4 is added to 750 ml of water. More water is added until the total volume is 1 liter. This is done like this to avoid adding water to sulfuric acid.

50 ml of distilled water, add 20 ml concentrated H2SO4. Exothermic, so proceed slowly. Vessel should be cooled in ice bath.

10M sulfuric acid solution
mix equal parts by volume of water and H2SO4. This will get very hot! Cool it or mix slowly. Add the acid to the water (if it splashes this ensures the acid is the limiting reagent).
copper(II) carbonate
CuCO3, cupric carbonate
ammonia
NH4OH, NH3(aq), aqueous ammonia, ammonia water. Pure ammonia is a gas. NH4OH is incorrect; although, this formula is often used because it's more familiar.

disposal

Neutralize copper solution using 1 M HCl. Neutralize H2SO4 with NaHCO3.

Cupric carbonate method

Dissolve 2.27 g CuCO3 in 50 mL NH3(aq) under fume hood. Add cellulose, still until dissolved. Solution is injected into 3M H2SO4 to precipitate cellulose fibers.

Schweizer's reagent method

If cupric carbonate is not available it may be prepared.