Chad S. answered • 05/01/24
Secondary STEM Tutor who Emphasizes Purposeful Learning
Let's start with writing the balanced equation for this reaction.
Cu(NO3)2 + 2NaOH --> Cu(OH)2 + 2NaNO3
What are we starting with, or what do we know?
The amount (in grams) of Cu(NO3)2 = 11.436 g Cu(NO3)2
How can we go from mass of a substance to mass of a different substance?
We can use the molar mass to convert from grams to moles (and vice versa).
We can use the molar ratio (from the equation) to convert from moles of one substance to moles of another substance.
First, let's convert the mass of copper (ii) nitrate to moles of copper (ii) nitrate:
(11.436 g Cu(NO3)2) x (1 mole Cu(NO3)2 / 187.5 g Cu(NO3)2) = 0.060992 moles Cu(NO3)2
Now we can use the molar ratio from our equation to convert from Cu(NO3)2 to Cu(OH)2.
(0.060992 moles Cu(NO3)2) x (1 mole Cu(OH)2 / 1 mole Cu(NO3)2) = 0.060992 moles Cu(OH)2
Lastly, convert those moles of copper (ii) hydroxide to grams using its molar mass.
(0.060992 moles Cu(OH)2) x (97.5 g Cu(OH)2 / 1 mole Cu(OH)2) = 5.94672 g Cu(OH)2
We can have 5 significant digits... so mass of Cu(OH)2 is 5.9467 g Cu(OH)2
