This reaction won't go completion unless a precipitate (solid) or a gas is formed, so the observation may be NR for "no reaction".
Safety: Wear goggles and aprons! It's important to protect your eyes and skin! And wash your hands after the lab!
A simple video is available online:
And this is sort of cute:
One example of a lab is:
This site has 2 labs, but I like (1) the chart on the 1st page and (2) the page of reactions to be completed on the 4th page.
A half sheet of plastic overhead could be placed over the chart on Page 1 and the reactions performed right over the chart. The chart can then by slid away for the result to be written on the paper, and then slid back. (Thanks to Ray Hamilton at Greenwich High School for that idea!)
Another lab with fewer reactants is:
If you want to mention it, there's a little "Equilibrium" preview in these reactions b/c a precipitate or gas is necessary for the reaction to occur -- this way the reaction will go to completion as the product leaves the system!
These equations involve students working with (a) balancing equations and (b) solubility rules.
Balancing double replacement reactions can be easier if the polyatomic ions are counted as a unit. For example NO3- as one unit versus one nitrogen atom and 3 oxygen atoms -- if the polyatomic ion changes, this won't work.
2 AgNO3 (aq) + ZnCl2 (aq) --> 2 AgCl (s) + Zn(NO3)2
I did allow students to put in parentheses even though they weren't required -- they just had be used accurately. This would make balancing with polyatomic ions a little bit easier.
Ag(NO3) (aq) + ZnCl2 (aq) --> 2 AgCl (s) + Zn(NO3)2
where the "nitrate" unit was counted versus the individual nitrogen and oxygen. This made balancing much easier -- sometimes students would put parentheses in the middle of the polyatomic ion -- e.g. (NO)3 vs. (NO3) -- and they would not receive credit for those examples on homework/lab/quiz/test.
I don't really have any other tricks for balancing equations -- my approach was always a very simple comparing back and forth comparison of reactants and products. I guess I'm sort of "old school" this way.
I'd love to hear about any systems the work for your students!
Some teachers have students remember solubility rules:
This reference table is very handy, and if you're not familiar with it you might want to print yourself a copy. I would use tables selectively and include some tables on quizzes/tests.
My schedule for this blog is changing... again.. after today, I will post new entries on two days, Wednesday and Sunday. This way I can provide a well researched entry.
Please let me know about your experience with these labs, ask if you have any questions or if you have ideas for other topics for this blog.
And, check out my lab book "Chemistry on a Budget" at:
Have a good weekend!