Answer: The pOH is: " 2.40 " . 
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 The pOH value of a 0.0010 M solution of calcium hydroxide; 
 Ca(OH)₂ ; is: 
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 " 2.40 " .
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Step-by-step explanation:
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Calculate the pOH of a 0.0010 M solution of Ca(OH)₂ . 
Note that: 
 "M" represents the concentration in "Molarity" ;
 (that is; "moles of solute per Liter of solution" ; or, "mol / L " } ;
and that for our purposes, anything notes in "brackets" refers to "concentration"; in "M" {"Molarity" ; as explained above.}. 
 
Note that "calcium hydroxide", that is; " Ca(OH)₂ " ; 
 → dissociates into the following ions, as follows:
 → Ca(OH)₂ → Ca²⁺ + 2 OH⁻ ; 
 
Therefore, the [OH⁻] equals: {2 * 0.0010} M = 0.0040 M . 
For every Ca(OH)₂ you produce 2 OH⁻ . 
 
Note:  pOH = - log [OH⁻] ; 
pOH = - log ( 0.0040) = 2.3979400086720375 ; 
 → round to: " 2.40 " . 
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Answer: The pOH is: " 2.40 " . 
__________________________________________________________
 The pOH value of a 0.0010 M solution of calcium hydroxide; Ca(OH)₂ ; is: 
 " 2.40 " .
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