Tips on making Bordeaux Mixture (and the chemistry behind it)

[ungvichian]

I know this might be general knowledge somewhere, but...

We would like tips on making Bordeaux Mixture. We found some tips on ratios thusly:

• General: CuSO4 100g / Ca(OH)2 100-200g / H2O 10l

• Allergic to Copper: CuSO4 40g / Ca(OH)2 120g / H2O 4l

• Young: CuSO4 10g / Ca(OH)2 30g / H2O 4l

Are these ratios sound or not?

Also, we would like to know the whole chemistry behind Bordeaux Mixture, because from what we know:

• Ca(OH)2 dissolves at only 0.18g/100mL of water.

• The CuSO4 and Ca(OH)2 react to create Cu(OH)2 and CaSO4, which are both insoluble (while leaving a excess of Ca(OH)2 as well).

[Ron Jones]

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