1) Write a balanced chemical equation for the reaction between Cu(NO3)2 * 3 H2O and NaOH. Underline the formula for the precipitate produced by this reaction. (The water of hydration in Cu(NO3)2 * 3 H2O appears as liquid water on the right side of the equation)
1. Cu(NO3)2.3H2O(aq) + NaOH(aq) --> Cu(OH)2(s) + H2O + NaNO3(aq)
We can't underline but (s) means a solid ppt. You will need to balance it.
Why is Cu(OH)2 the precipitate in this solution? Shouldn't it be NaNO3?
No. NaNO3 is soluble. Cu(OH)2 is not soluble. Here is a list of solubility rules.
http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html
The precipitate in this reaction is Cu(OH)2, not NaNO3, because when Cu(NO3)2 * 3 H2O reacts with NaOH, the reaction produces Cu(OH)2 as an insoluble solid, which means it forms a precipitate. NaNO3, on the other hand, remains dissolved in the aqueous solution and does not form a solid precipitate.
To understand why Cu(OH)2 is the precipitate, we need to consider the solubility rules for common ionic compounds. Cu(OH)2 is insoluble in water, which means it does not easily dissolve and forms a solid when it comes into contact with water or an aqueous solution. On the other hand, NaNO3 is a soluble salt, meaning it readily dissolves in water to form a homogeneous solution.
To determine the precipitate in a reaction, you can use solubility rules or consult a solubility table, which lists the solubility properties of different compounds. In this case, referring to the solubility rules or table would indicate that Cu(OH)2 is insoluble and will form a solid precipitate, while NaNO3 is soluble and will remain as an aqueous solution.