Author Topic: Mushy NaOH  (Read 1571 times)

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Bwiti

  • Guest
Mushy NaOH
« on: November 26, 2001, 10:54:00 PM »

  I have a big-ass container of NaOH, and 2 weeks ago I didn't properly cover it, so now it's looking fairly mushy from absorbed water in the air. The problem is that I need to make 181 ml 45% NaOH solution, but when I weigh out the NaOH, I know they'll be water in it. How much NaOH should I use to come close to a 45% solution? Peace!   8)

  Split a piece of wood and I am there. Lift a stone and you will find me.

yellium

  • Guest
Re: Mushy NaOH
« Reply #1 on: November 26, 2001, 11:20:00 PM »
Make a density-vs-concentration graph, starting with `pure' NaOH. Or use the data from the table below:
1: Baume (silly unit)
2: density (kg/l)
3: concentration (by weight, in g/kg)
4: concentration (by weight, in %w/w/)
5: concentration (by volume)

1 2     3    4     5
---------------------
1 1.007 5.9 0.59% 6.0
2 1.014 12.0 1.20% 12.0
3 1.022 18.5 1.85% 18.9
4 1.029 25.0 2.50% 25.7
5 1.036 31.5 3.15% 32.6
6 1.045 37.9 3.79% 39.6
7 1.052 45.0 4.50% 47.5
8 1.060 52.0 5.20% 55.0
9 1.067 58.6 5.86% 62.5
10 1.075 65.8 6.58% 70.7
11 1.083 73.0 7.30% 79.1
12 1.091 80.7 8.07% 88.0
13 1.100 87.8 8.78% 96.6
14 1.108 95.0 9.50% 105.3
15 1.116 103.0 10.30% 114.9
16 1.125 110.6 11.06% 124.4
17 1.134 118.4 11.84% 134.0
18 1.142 126.9 12.69% 145.0
19 1.152 135.0 13.50% 155.5
20 1.162 143.5 14.35% 166.7
21 1.171 151.5 15.15% 177.4
22 1.180 160.0 16.00% 188.8
23 1.190 169.1 16.91% 201.2
24 1.200 178.1 17.81% 213.7
25 1.210 187.1 18.71% 226.4
26 1.220 196.5 19.65% 239.7
27 1.231 206.0 20.60% 253.6
28 1.241 215.5 21.55% 267.4
29 1.252 225.0 22.50% 281.7
30 1.263 235.0 23.50% 296.8
31 1.274 244.8 24.48% 311.9
32 1.285 255.0 25.50% 327.7
33 1.297 265.8 26.58% 344.7
34 1.306 276.5 27.65% 361.7
35 1.320 288.3 28.83% 380.6
36 1.332 300.0 30.00% 399.6
37 1.345 312.0 31.20% 419.6
38 1.357 325.0 32.50% 441.0
39 1.370 337.3 33.73% 462.1
40 1.383 350.0 35.00% 484.1
41 1.397 363.6 36.36% 507.9
42 1.410 376.5 37.65% 530.9
43 1.424 390.6 39.06% 556.2
44 1.438 404.7 40.47% 582.0
45 1.453 420.2 42.02% 610.6
46 1.468 435.8 43.58% 639.8
47 1.483 451.6 45.16% 669.7
48 1.498 467.3 46.73% 700.0
49 1.514 484.1 48.41% 732.9
50 1.530 501.0 50.10% 766.5







Osmium

  • Guest
Re: Mushy NaOH
« Reply #2 on: November 26, 2001, 11:54:00 PM »
For most applications the concentration isn't that important, and I bet in that procedure of yours the NaOH is only used to basify something and the amount isn't critical. In that case prepare a nearly saturated solution and use that instead.
If you really need exact concentrations then buy some new NaOH, it's not that expensive. Use the wet NaOH for "everyday" basifications, to clean your toilet, unclog your sinks, disposing of dead bodies etc.

Bwiti

  • Guest
Re: Mushy NaOH
« Reply #3 on: November 27, 2001, 12:11:00 AM »
"I bet in that procedure of yours the NaOH is only used to basify something and the amount isn't critical."

  Lets say that an evil chemist wants to bubble HCN into the NaOH/water to make a solution of NaCN, then add an amine and methylcyclohexanone to make a nitrile. Too little NaOH will leave unreacted HCN, but how would extra hydroxide effect the formation of a nitrile? 

  Split a piece of wood and I am there. Lift a stone and you will find me.