Write the net ionic formula.
A bar of strontium metal is immersed in a 1.0 M copper (II) nitrate solution.
How do I go about doing this?
There are two reactions here.
1) Strontium is an active metal what will react with water, forming Strontium hydroxide (aq), and releasing hydrogen gas in the form of bubbles.
Sr + 2H+ + 2OH- >> Sr++ + 2OH- + H2 (g)
2) The second reaction is that Strontium will replace the Copper(II) ions in the cupric nitrate, precipating copper
I will be happy to critique your thinking on that reaction.
I believe I am to write the second one down. Does the 1.0 M even come into play in this problem?
No, the strength of the copper(II) solution is not used. It must be something, in order to plate out Cu metal, but the actual number, unless you were calculating the amount of copper plated out, is not needed.
Ok, I thought that was just thrown in to test us. That's what I needed to know. Let me give it another go...
To write the net ionic formula for a chemical reaction, you need to first determine the reactants and products in the reaction. Then, you write out the balanced equation for the overall reaction and finally, you cancel out the spectator ions to obtain the net ionic formula.
In this case, we have a bar of strontium metal (Sr) being immersed in a copper (II) nitrate solution. The copper (II) nitrate formula is Cu(NO3)2.
Step 1: Write the balanced equation for the overall reaction.
Strontium metal (Sr) will react with copper (II) nitrate (Cu(NO3)2) to form strontium nitrate (Sr(NO3)2) and copper metal (Cu).
Sr(s) + Cu(NO3)2(aq) → Sr(NO3)2(aq) + Cu(s)
Step 2: Identify the spectator ions.
In the reaction, the copper (II) nitrate and strontium nitrate are both soluble in water and exist as dissociated ions. The only insoluble product is copper metal (Cu), which is a solid and does not dissociate. Therefore, the spectator ions in this reaction are NO3-.
Step 3: Write the net ionic formula by canceling out the spectator ions.
The net ionic formula is obtained by removing the spectator ions from the reaction equation:
Sr(s) + 2 Cu2+(aq) → Sr2+(aq) + 2 Cu(s)
Therefore, the net ionic formula for the reaction is Sr(s) + 2 Cu2+(aq) → Sr2+(aq) + 2 Cu(s).