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Conversion tables

Key information for the working scientist

As a trusted partner with a passion for science, Avantor® offers a broad array of useful conversion tables and formulas to help your research and production to set science in motion.

Particle size1

Sieve "Mesh" Sieve Opening
  Inches Millimeters
1 1.00 25.4
7/8 0.875 22.6
3/4 0.750 19.0
5/8 0.625 16.0
.530 0.530 13.5
1/2 0.500 12.7
7/16 0.438 11.2
3/8 0.375 9.51
5/16 0.312 8.00
.265 0.265 6.73
1/4 0.250 6.35
3 1/2 0.223 5.66
4 0.187 4.76
5 0.157 4.00
6 0.132 3.36
7 0.111 2.83
8 0.0937 2.38
10 0.0787 2.00
12 0.0661 1.68
14 0.0555 1.41
16 0.0469 1.19
18 0.0394 1.00
20 0.0331 0.841
25 0.0278 0.707
30 0.0234 0.595
35 0.0197 0.500
40 0.0165 0.420
45 0.0139 0.354
50 0.0117 0.297
60 0.0098 0.250
70 0.0083 0.210
80 0.0070 0.177
100 0.0059 0.149
120 0.0049 0.125
140 0.0041 0.105
170 0.0035 0.088
200 0.0029 0.074
230 0.0025 0.063
270 0.0021 0.053
325 0.0017 0.044
400 0.0015 0.037

1. Large sieve opening (1 to 1/4 inch) have been designated a sieve "mesh" size that corresponds to the size of the opening in inches.

Sieve "mesh" sizes of 31/2 and higher are designated by the number of openings per linear inch in the sieve.

Note: To convert millimeters to microns, move decimal point three places to the right. Example: 0.125 millimeters converts to 125 microns.


Acid / Base Concentrations

Composition of concentrated reagent-grade acids, ammonium hydroxide, and sodium and potassium hydroxide solutions (with dilution directions to 1M and 1N solutions)

Chemical Formula Weight of Reagenta Approximate Density Approximate Strength of Concd. Reagentb Assay Limits % w/w Molarity of Concd. Reagent Milliliters of Concd. Reagent Necessary to Prepare 1 Liter of 1 Molar Solutionc Normality of Concd. Reagent Milliliters of Concd. Reagent Necessary to Prepare 1 Liter of 1 Normal Solutionc
Acetic Acid (CH3COOH) 60.052 1.05 99.8 99.7–99.9 17.4 57.5 17.4 57.5
Formic Acid (HCOOH) 46.026 1.13 90 88.0–92.0 23.6 42.5 23.6 42.5
Hydrochloric Acid (HCI) 36.461 1.18 37.2 36.5–38.0 12.1 82.5 12.1 82.5
Hydrofluoric Acid (HF) 20.006 1.19 49 48.0–51.0 28.9 34.5 28.9 34.5
Nitric Acid (HNO3) 63.013 1.41 69.6 69.0–70.0 15.6 64 15.6 63
Perchloric Acid (HCIO4) 100.458 1.67 70.5 70.0–72.0 11.7 85.5 11.7 85.5
Perchloric Acid (HCIO4) 100.458 1.67 61.3 60.0–62.0 9.5 105.5 9.5 105.5
Phosphoric Acid (H3PO4) 97.995 1.71 85.5 85.0–87.0 14.8 67.5 44.4 22.5
Sulfuric Acid (H2SO4) 98.073 1.84 96 95.0–98.0 18 55.5 36 28
Ammonium Hydroxide (NH4OH) 35.046 0.90 56.6d 14.5 69 14.5 69
Sodium Hydroxide (NaOH) 39.997 1.53 50.5 50.0–52.0 19.4 51.5 19.4 51.5
Potassium Hydroxide (KOH) 56.105 1.45 45 45.0–46.0 11.7 85.5 11.7 85.5

a. Based on atomic weight table (32C = 12).

b. Representative value, w/w %.

c. Rounded to nearest 0.5 ml.

d. Equivalent to 28.0 % w/w NH3.