<p>Yeah it’s easy. You double the charge of Nickel, so 2+ * 2 = 4, and that’s how many ammonia’s you need because ammonia is a ligand. You will most likely see one of these on the test on Monday - the common ligands to look for can include OH-, NH3, and SCN, among a few others.</p>
<p>You know that answer key seems off to me because on the 4A example, they gave the answer “Ni2+ +4NH3 –>[Ni(NH3)4]2+” full points. I think that ligand = 2x times the charge rule still applies.</p>
<p>yeah, how does it not? Ni2+ +4NH3 –>[Ni(NH3)4]2+ is completely correct.</p>
<p>Im so confused now.</p>
<p>Scoring guideline says 6 amminos, but the sample response has 4 and the guy got 15/15 points</p>
<p>Which is it?</p>
<p>And , now i see the second sample guy got full credit and he had just 1 ammino. What is going on, im so confused. Can you just add how ever many ligands you want?</p>
<p>If you use the general rule and it’s off from the “correct” answer, they won’t mark you off. As long as you have the right product.</p>
<p>I dont think it matters.</p>
<p>The 2x is just a rule of thumb. </p>
<p>Can anyone explain anhydrides and what they usually produce in the Descriptive Chem section?</p>
<p>hey guys. 
i was jw…what are the chances of having an organic reaction for #4 of the FR?
we didn’t learn anything about it at all in class, and it’s kinda confusing too. Idk if I should go through all the trouble to study them -.-
@misteranthony according to my barron’s book, anhydride : the oxide of a metal or nonmetal that reacts with water to form an acid or base, respectively. 
I hope that helps~</p>
<p>anhydrides:
CaO + 2 HCl → CaCl2 + H2O</p>
<p>It’s a metal or nonmetal oxide (here we have a metal oxide) , usually if it reacts with a acid or base, it simply does a double replacement and then creates H2O. Treat it like it’s reacting a base with an acid. (Similar products)</p>
<p>net. CaO + 2 H+→ Ca2++ H2O</p>
<p>Is there ever any Lattice Energy Questions, like the one’s with body centered and face centered cubic stuff, one the frqs?</p>
<p>There may be questions about lattice energy, but nothing about the ionic bonding cubes.</p>
<p>I find the reactions are the easiest part…the point gainers. Probably because my teacher has been giving us reactions every 2 weeks throughout the year.
The MC is the hardest part part for me. I usually get ~50 questions right…the FRQs are slightly easier.</p>
<p>And there’s no chance for an organic reaction. Maybe not even a complex reaction according to my teacher. </p>
<p>The easiest way to gain points on the FRQ is just put something down. Maybe the rubric will award you points just for putting an equation down!</p>
<p>They f****** put a complex reaction, I had no clue on it.</p>
<p>I missed all three reactions on #4.</p>