1 normal acid or base (1N)

From OpenWetWare

(Difference between revisions)
Jump to: navigation, search
(categories)
(table)
Line 3: Line 3:
* 1 M (mol/l) = 1 N for an acid that releases 1 proton* when dissolved in water, e.g. HCL (*monoprotic)
* 1 M (mol/l) = 1 N for an acid that releases 1 proton* when dissolved in water, e.g. HCL (*monoprotic)
* 1 M (mol/l) = ''2'' N for an acid that releases 2 protons*, e.g. H<sub>2</sub>SO<sub>4</sub> (*diprotic)
* 1 M (mol/l) = ''2'' N for an acid that releases 2 protons*, e.g. H<sub>2</sub>SO<sub>4</sub> (*diprotic)
 +
 +
For example, some antigen retrieval methods use 2N hydrochloric acid to open up the tissue to allow antibody binding. This could be a nucleotide analogue, as BrdU or dUTP-TMR in cell proliferation of apoptosis assays.
 +
 +
{| {{table}} OR border=1 cellpadding=5 cellspacing=0 OR {{sorttable}}
 +
! style="background:lightgrey"|acid/case
 +
! style="background:lightgrey"|molecular weight
 +
! style="background:lightgrey"|N vs M
 +
|-
 +
| HCl -> <font color=blue>1·H<sup>+</sup></font> + Cl<sup>-</sup>
 +
| 36.5 g/mol
 +
| 1N = 1M = 36.5g/L
 +
|-
 +
| H<sub>2</sub>SO<sub>4</sub> -> <font color=blue>2·H<sup>+</sup></font> + SO<sub>4</sub><sup>2-</sup>
 +
| 98 g/mol
 +
| 2N = 1M = 98g/L
 +
|-
 +
| NaOH -> Na<sup>+</sup> + <font color=blue>1·OH<sup>-</sup></font>
 +
| 40 g/mol
 +
| 1N = 1M = 40g/L
 +
|}
 +
By the way, ''molarity M'' is also a non-standard unit[http://physics.nist.gov/cuu/Units/checklist.html]. Expressing this explicitly as mol/L or mol/m<sup>3</sup> is clearer to readers less versed in current biological customs.
By the way, ''molarity M'' is also a non-standard unit[http://physics.nist.gov/cuu/Units/checklist.html]. Expressing this explicitly as mol/L or mol/m<sup>3</sup> is clearer to readers less versed in current biological customs.

Revision as of 12:45, 8 December 2010

Biologists are sometimes confused by the non-standard[1] chemical unit of normality N. N refers in general to salts while it's most commonly used in the context of acid and bases.

  • 1 M (mol/l) = 1 N for an acid that releases 1 proton* when dissolved in water, e.g. HCL (*monoprotic)
  • 1 M (mol/l) = 2 N for an acid that releases 2 protons*, e.g. H2SO4 (*diprotic)

For example, some antigen retrieval methods use 2N hydrochloric acid to open up the tissue to allow antibody binding. This could be a nucleotide analogue, as BrdU or dUTP-TMR in cell proliferation of apoptosis assays.

acid/case molecular weight N vs M
HCl -> 1·H+ + Cl- 36.5 g/mol 1N = 1M = 36.5g/L
H2SO4 -> 2·H+ + SO42- 98 g/mol 2N = 1M = 98g/L
NaOH -> Na+ + 1·OH- 40 g/mol 1N = 1M = 40g/L


By the way, molarity M is also a non-standard unit[2]. Expressing this explicitly as mol/L or mol/m3 is clearer to readers less versed in current biological customs.

See also

Personal tools