各酸的物性参数_Acids_Alkaline

Hans-J. Grapentin ( July 2001 )

Practical Training

How to mix solutions ? (example one )

Our pH Correction Solution CC is a quality controlled, 32% w/w sodium hydroxide solution. Calculated by the density ( 1,35 g/cm³ ) the solution contains 432g NaOH per litre.

Our customer like to use a NaOH solution which is 50 % w/w – the density is 1,526 g/cm³.

This product is in the same quality, but you need to dilute to 32 % w/w.

How is the right mixture procedure ?

Cross rule :

50 32 weight parts of 50 % w/w NaOH (divided by 1,526) = 20,970 ml 32 = 566,2 ml/l

0 18 weight parts of DI – water * 16,067 ml 50 weight parts of 32 % w/w NaOH (divided by 1,35) = 37,037 ml

* 37,037 – 20,970 ml = 16,067 ml water !

Result : ( To mix 100 litre of 32 % w/w sodium hydroxide solution )

We need 56,62 litre ( 86,40 kg ) NaOH, 50 % w/w and have to fill up with DI – water to 100 litre ( related to volume contraction ).

Hans – J. Grapentin (July 2001)

Practical Training

How to mix solutions ? ( example two )

How is the right mixture to get a 40 % by weight sodium hydroxide solution ( density d = 1,43 g/cm3 ), when you have to mix it with :

Sodium hydroxide, 50 % w/w (d = 1,526 g/cm3) and Sodium hydroxide, 32 % w/w (d = 1,35 g/cm3) ?

Cross rule :

50 = 8 weight parts of 50 % NaOH (divided by 1,526) = 5,2425 ml 40 32 = 10 weight parts of 32 % NaOH* 7,3449 ml 18 weight parts of 40 % NaOH (divided by 1,43) =12,5874 ml

* 12,5874 – 5,2425 = 7,3449 ml NaOH, 32 % w/w !

Result :

To get 100 litre of sodium hydroxide, 40 % by weight it must be mixed with : 41,65 litre (63,56 kg) of NaOH, 50 % w/w and 58,35 litre (78,77 kg) of NaOH, 32 % w/w.

The volume contraction is very little here and for this negligible.

Densities of solutions @ 18 ° C

1) H2O2 2) H2 So4 3) H3 Po4 4) HCL

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