Water: Difference between revisions

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{{compound|aka=|distilled water, ice|chemf=H2O
{{compound|aka=distilled water, ice|chemf=H2O
|mp=0.1|bp=100|mm=18|density=1|solvent=pp|ior=1.333|sol_et=misc|eof=−187.80
|mp=0.1|bp=100|mm=18|density=1|solvent=pp|ior=1.333|sol_et=misc|eof=−187.80|hc_l=4.2|hf=333|hv=2257
|stp_p=liquid|stp_q=clear
|stp_p=liquid|stp_q=clear
}}
}}
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==Uses==
==Uses==
===Primary===
===Primary===
* Drinking water is essential to human life
* Water is essential to human life
* In chemistry, it is a common polar solvent
* In chemistry, it is a common polar solvent
* Ice is a key thermal absorption material
* Ice is a key thermal absorption material
* Triple point is key in thermal measurement and calibration of thermometers.
===Secondary===
===Secondary===
* Expansion on freezing is a key mechanic in early stone splitting
* Expansion on freezing is a key mechanic in early stone splitting
==Natural occurrence==
==Natural occurrence==
* Water occurs naturally
* Water occurs naturally
** as ''fresh water'' (ultimately derived from rain)
** as [[fresh water]] (ultimately derived from rain)
*** Rain
*** Rain
*** Springs
*** Springs
*** Rivers
*** Rivers
*** Lakes
*** Lakes
** and ''salt water'' from
** and [[salt water]] from
*** oceans
*** Oceans
*** seas
*** Seas
*** salt lakes
*** Salt lakes
*** brine deposits
*** Brine pools
* Structural water occurs in many minerals
* Structural water occurs in many minerals
* Many plants contain an abundance of water
* Many plants contain an abundance of water
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==Hazards==
==Hazards==
* Drowning
* Drowning
* Overconsumption (>= 2L/hr for multiple hours when normally hydrated) can lead to hyponatremia
* Overconsumption (≥2L/hr for multiple hours when normally hydrated) can lead to hyponatremia
 
==Character==
* Boiling point<sub>&deg;C</sub> = 65.8 + 0.045P<sub>mmHg</sub>
** Inside the "normal" atmospheric pressure range (750-770) the boiling point of water remains within {{pm|100|0.5}}&deg;C.
** To get down to a boiling point of 99&deg;C, you would need a pressure below 738 (mmHg)
** To get up to a boiling point of 101&deg;C, you would need a pressure above 782 (mmHg)
* Resistivity &rho;<sub>cm@25&deg;C</sub> = 18.18 MΩ
** 0.055 micro-siemens/cm
 
==Production==
==Production==
===Extraction===
===Extraction===
* Pure water can be extracted from ''fresh water'' and ''salt water'' by distillation. {{vid |url=X}}
* Pure water can be extracted from ''fresh water'' and ''salt water'' by [[distillation]].
 
===Synthesis===
===Synthesis===
====from hydrogen gas====
====from hydrogen gas====
# Burn [[hydrogen]] in air, directing the combustion products to a condenser {{vid|url=X}}
# Burn [[hydrogen]] in air, directing the combustion products to a condenser
#: {{#Chem: 2H2 + O2 { = combustion } H2O(v)}}
#: {{#Chem: 2H2 + O2 { = combustion } H2O(v)}}
# Condense the water formed
# Condense the water formed
====As a side product====
====As a side product====
Many chemical reactions, particularly acid/base reactions (e.g. acetic acid and calcium hydroxide), produce water as a side product.  
Many chemical reactions, particularly acid/base reactions (e.g. acetic acid and calcium hydroxide), produce water as a side product.  
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==Testing==
==Testing==
===[[Quantitative tests]]===
===[[Quantitative tests]]===
# Density
# Density 1.0
# Boiling point
# Triple point 0.01&deg;C
# Melting point
# Boiling point 100&deg;C
# pH 7.0
# Resistivity 18M&Omega;/cm


===[[Qualitative tests]]===
===[[Qualitative tests]]===
# Visual: Clear, colorless
# Visual: Clear, colorless
#* Adding a few drops of [[silver nitrate]] will show chlorides, carbonates, hydroxides, and sulfates as insoluble precipitates
# Smell: None
# Smell: None
# Taste: Characteristic
# Taste: Characteristic
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==Purification==
==Purification==
===Filtration===
===Filtration===
# Passing water through clean, fine  [[sand]] will remove some [[:Category:Monads|microorganisms]].
# [[Filtration|Filtering]] water through clean, fine  [[sand]] will remove some [[:Category:Monads|microorganisms]].
# Passing water through [[charcoal]] or [[activated charcoal]] will remove toxins such as cyanide.
# Filtering water through [[charcoal]] or [[activated charcoal]] will remove toxins such as cyanide.
Arranging a filter with layers of sand and charcoal is an effective way to produce relatively clean (unpotable) water. It should still be boiled before drinking.
Arranging a filter with layers of sand and charcoal is an effective way to produce relatively clean water. It should still be boiled before drinking.
 
===Boiling===
Boiling fresh or salt water will render it relatively safe to drink as far as [[:Category:Monads|monad]] pathogens go. This will not, generally, remove or change and dissolved compounds, so the salt in salt water, or other potentially harmful materials, will remain.
===Distillation===
===Distillation===
: Distilled water is water that has been condensed from a gas and stored in a clean container. Distilled water has ''no'' dissolved solids and is completely sterile.
: [[Distillation| Main Article: Distillation]]
Distilled water is water that has been condensed from a pure water vapor. In simple cases this will render it both completely free of contaminants and totally sterile.
# distil water
# distil water
# discard residue
# discard residue
# distillate is distilled water
# distillate is distilled water
: '''NB:''' Some contaminants form fixed gaseous mixtures with water. (e.g. [[ammonia]], [[ethanol]], [[sulfuric acid]]) These are not easily removed by simple distillation.
: '''NB:''' Some contaminants form fixed gaseous mixtures with water. (e.g. [[ethanol]], [[sulfuric acid]]) These are not easily removed by simple distillation.


===Other===
===Other===
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Water can be safely discarded into the environment
Water can be safely discarded into the environment
==See Also==
==See Also==
* [[Fresh water]] vs [[salt water]]
* [[Fresh water]] vs [[salt water]]
==References==
==References==
<references/>
<references/>
[[Category:Natural Materials]]

Latest revision as of 09:40, 5 June 2020

 
Water
aka distilled water, ice
Chemical formula H2O
OTP appearance clear liquid 
Index of refraction 1.333 
Molar Mass(g/mol) 18 
Enthalpy of Formation(kJ/mol) −187.80 
Density(g/cc) 1 
Melting Point(°C) 0.1 
Boiling Point(°C) 100 
Solubility in ethanol(g/L) misc
NFPA 704
NFPA704.png
0
0
0
 

Water, in the English language, is an inexact term. This article deals with the chemical compound H2O: pure water.

Uses

Primary

  • Water is essential to human life
  • In chemistry, it is a common polar solvent
  • Ice is a key thermal absorption material
  • Triple point is key in thermal measurement and calibration of thermometers.

Secondary

  • Expansion on freezing is a key mechanic in early stone splitting

Natural occurrence

  • Water occurs naturally
    • as fresh water (ultimately derived from rain)
      • Rain
      • Springs
      • Rivers
      • Lakes
    • and salt water from
      • Oceans
      • Seas
      • Salt lakes
      • Brine pools
  • Structural water occurs in many minerals
  • Many plants contain an abundance of water

Hazards

  • Drowning
  • Overconsumption (≥2L/hr for multiple hours when normally hydrated) can lead to hyponatremia

Character

  • Boiling point°C = 65.8 + 0.045PmmHg
    • Inside the "normal" atmospheric pressure range (750-770) the boiling point of water remains within 100±0.5°C.
    • To get down to a boiling point of 99°C, you would need a pressure below 738 (mmHg)
    • To get up to a boiling point of 101°C, you would need a pressure above 782 (mmHg)
  • Resistivity ρcm@25°C = 18.18 MΩ
    • 0.055 micro-siemens/cm

Production

Extraction

  • Pure water can be extracted from fresh water and salt water by distillation.

Synthesis

from hydrogen gas

  1. Burn hydrogen in air, directing the combustion products to a condenser
    2 H2 + O2
    {
    →
    combustion}
    H2O(v)
  2. Condense the water formed

As a side product

Many chemical reactions, particularly acid/base reactions (e.g. acetic acid and calcium hydroxide), produce water as a side product.

2 CHCOOH + Ca(OH)2 → Ca(CH3COO)2 + 2 H2O // acetic acid and calcium hydroxide produce calcium acetate and water

Testing

Quantitative tests

  1. Density 1.0
  2. Triple point 0.01°C
  3. Boiling point 100°C
  4. pH 7.0
  5. Resistivity 18MΩ/cm

Qualitative tests

  1. Visual: Clear, colorless
    • Adding a few drops of silver nitrate will show chlorides, carbonates, hydroxides, and sulfates as insoluble precipitates
  2. Smell: None
  3. Taste: Characteristic
  4. Approximate Viscocity : Characteristic

Purification

Filtration

  1. Filtering water through clean, fine sand will remove some microorganisms.
  2. Filtering water through charcoal or activated charcoal will remove toxins such as cyanide.

Arranging a filter with layers of sand and charcoal is an effective way to produce relatively clean water. It should still be boiled before drinking.

Boiling

Boiling fresh or salt water will render it relatively safe to drink as far as monad pathogens go. This will not, generally, remove or change and dissolved compounds, so the salt in salt water, or other potentially harmful materials, will remain.

Distillation

Main Article: Distillation

Distilled water is water that has been condensed from a pure water vapor. In simple cases this will render it both completely free of contaminants and totally sterile.

  1. distil water
  2. discard residue
  3. distillate is distilled water
NB: Some contaminants form fixed gaseous mixtures with water. (e.g. ethanol, sulfuric acid) These are not easily removed by simple distillation.

Other

  • The mineral witherite is sometimes used for the removal of calcium and magnesium sulfates from water via precipitation
    2 BaCO3(s) + CaSO4(aq) + MgSO4(aq) → CaCO3(s) + MgCO3(s) + BaSO4(s)

Storage

Store in watertight containers.

Disposal

Water can be safely discarded into the environment

See Also

References

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