1 normal acid or base (1N): Difference between revisions
From OpenWetWare
Jump to navigationJump to 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 09:45, 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.
