Difference between revisions of "Sodium hydroxide"

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# Prepare a saturated solution of ½mol of sodium carbonate:
 
# Prepare a saturated solution of ½mol of sodium carbonate:
 
#* 53 ubm [[sodium carbonate|anhydrous sodium carbonate]] dissolved in 211 ubm water
 
#* 53 ubm [[sodium carbonate|anhydrous sodium carbonate]] dissolved in 211 ubm water
# Add ½ mol (37 ubm) [[calcium hydroxide]], precipitating [[calcium carbonate]]
+
# Add ½ molar fraction (37 ubm) of [[calcium hydroxide]], precipitating [[calcium carbonate]]
 
#: {{#Chem: 2Na2CO3 + Ca(OH)2 = NaOH(aq) + 2 CaCO3(s) // in about 7floz of water}}
 
#: {{#Chem: 2Na2CO3 + Ca(OH)2 = NaOH(aq) + 2 CaCO3(s) // in about 7floz of water}}
  

Latest revision as of 18:39, 27 July 2020

 
Sodium hydroxide
Chemical formula NaOH
OTP appearance white solid 
Molar Mass(g/mol) 39.9971 
Melting Point(°C) 318 
Boiling Point(°C) 1388 
Density(g/cc) 2.13 
Solubility in water(g/L) 1110
NFPA 704
NFPA704.png
0
3
1
ALK

Uses

Primary

  • Industrial chemical
  • Primary component in lye
  • Primary alkali used to produce sodium salts from acids

Natural occurrence

  • Sodium hydroxide does not occur naturally.

Hazards

Sodium hydroxide is extremely caustic, especially when wet. Exposure of wet (slaked) lye to skin or eyes is likely to result in severe chemical burns and/or blindness.

Production

Synthesis

via calcium hydroxide

using saturated solutions

Combining a saturated solution of calcium hydroxide with sodium carbonate results in sodium hydroxide. This reaction is rapid but involves removing a large amount of water from the reactants for each mol of calcium.

  1. Prepare a saturated solution of ½mol of sodium carbonate:
  2. Prepare a saturated solution of ½mol of calcium hydroxide:
  3. Combine the solutions, precipitating calcium carbonate
    Ca(OH)2(aq) + Na2CO3(aq) 2 NaOH(aq) + CaCO3(s) // in almost 6 gallons of water
using dissolution over time

Combination of calcium hydroxide and sodium carbonate results in sodium hydroxide. This reaction is limited by the very low solubility and dissolution speed of calcium hydroxide.

  1. Prepare a saturated solution of ½mol of sodium carbonate:
  2. Add ½ molar fraction (37 ubm) of calcium hydroxide, precipitating calcium carbonate
    2 Na2CO3 + Ca(OH)2 NaOH(aq) + 2 CaCO3(s) // in about 7floz of water

Purification

Testing

Storage

Disposal

See Also

References