Some distilled water is added to an empty beaker. A gram of copper(II) nitrate is added to the beaker with stirring. After a few minutes, what is in the beaker?
a. solid copper(II) nitrate and water
b. nitrogen gas, copper atoms, electrons, and water
c. a sticky material of copper hydronitrite
d. solid copper, nitrate ions, and water
5. copper ions, nitrate ions, and water
e. copper ions, nitrate ions, and water.
a and b are eliminated because copper and nitrate turn out to be aqueous due to solubility rules.
that leaves you with b, c, and e.
with these types of problems, you'll never end up with electrons as the answer, it'll only ask you what the products are, and in the reactants, 'electrons' wasn't part of a compound.
lastly, you are with c and e.
this is pretty obvious as well, because H2O will stay H2O when you dissociate it, so you won't have copper hydronitrite. (Plus, that would require taking out oxygen and changing nitrate to nitrite, which doesn't follow the law of conservation of mass.
Cu(NO3)2 + H2O ==> Cu^+2(aq) + NO3^-(aq) + H2O (if you want to get technical there will be a SMALL amount of H^+ and a SMALL amount of OH^-
The correct answer is d. solid copper, nitrate ions, and water.
When a gram of copper(II) nitrate is added to distilled water and stirred, the copper(II) nitrate dissociates into its ions, copper(II) ions (Cu^2+) and nitrate ions (NO3^-). These ions then interact with water molecules resulting in the formation of hydrated copper(II) ions, Cu(H2O)6^2+, and nitrate ions.
The reaction can be represented as:
Cu(NO3)2(s) + 6H2O(l) -> Cu(H2O)6^2+(aq) + 2NO3^-(aq)
As a result, the beaker will contain solid copper, Cu(H2O)6^2+(aq) hydrated copper(II) ions, nitrate ions, NO3^-(aq), and water, H2O.
To determine what is in the beaker after adding distilled water and copper(II) nitrate, let's analyze the reaction and the resulting products.
Copper(II) nitrate is a compound composed of copper ions (Cu2+) and nitrate ions (NO3-). When this compound is dissolved in water, it dissociates into its respective ions:
Cu(NO3)2 (s) -> Cu2+ (aq) + 2NO3- (aq)
In the given scenario, the copper(II) nitrate is added to distilled water and stirred. Since copper is a solid compound, it will not dissolve immediately. However, over time, with stirring, the copper(II) nitrate will eventually dissolve in the water, resulting in the formation of copper ions (Cu2+) and nitrate ions (NO3-) in an aqueous solution.
Therefore, the correct answer is:
d. solid copper, nitrate ions, and water
Note that the copper ions and nitrate ions remain in the solution because they are soluble in water, whereas the solid copper does not dissolve completely and might settle at the bottom of the beaker.