200 likes | 1.92k Views
CHEMICAL REACTIONS. ChemQuest 28. LiBr + P Li 3 P + Br 2. Why is bromine written as Br 2 on the right side? Bromine is a diatomic molecule and always needs to be bonded to something; even bonding to itself works. LiBr + P Li 3 P + Br 2.
E N D
CHEMICAL REACTIONS ChemQuest 28
LiBr + P Li3P + Br2 • Why is bromine written as Br2 on the right side? • Bromine is a diatomic molecule and always needs to be bonded to something; even bonding to itself works.
LiBr + P Li3P + Br2 • Why is it not necessary for LiBr to be written as LiBr2? • If it were written LiBr2 it would not be a neutral compound.
Example Equation: Ca + HNO3 Ca(NO3)2 + H2 • What are the reactants in the example equation in the above information section? • Reactants are written on the left side of the equation and so the reactants are Ca and HNO3.
Na + MgCl2 NaCl + Mg • Why can’t NaMg be produced? • Na+ cannot bond with Mg2+ because they are both positive.
Na + MgCl2 NaCl + Mg • Why can’t NaCl2 be produced? • Na+ only requires one Cl-. NaCl2 is not a neutral compound.
Na + MgCl2 NaCl + Mg • Are NaCl and Mg the only products that can be produced? • Yes.
Li + Ca3(PO4)2 Li3PO4 + Ca • Why can’t CaLi2 be produced? • Ca2+ and Li+ won’t bond because they are both positive.
Li + Ca3(PO4)2 Li3PO4 + Ca • Why can’t Li3P be produced? • Although Li3P is neutral, there is no P3- in the equation. There is only PO43- and we will almost never be breaking up polyatomic ions like PO43-. • Don’t mess with polyatomic ions!
Li + Ca3(PO4)2 Li3PO4 + Ca • Are Li3PO4 and Ca the only substances that can be produced? • Yes.
Aluminum sulfate reacts with barium to produce barium sulfate and aluminum. • Al2(SO4)3 + Ba BaSO4 + Al
Magnesium reacts with copper(I) nitrate to produce magnesium nitrate and copper. • Mg + CuNO3 Mg(NO3)2 + Cu
Sodium reacts with calcium phosphide to produce sodium phosphide and calcium. • Na + Ca3P2 Na3P + Ca
Phosphorus reacts with sodium chloride to produce sodium phosphide and chlorine. • P + NaCl Na3P + Cl2 (Note that chlorine is diatomic!)
Each of the reactions you wrote in question 5 follows a similar pattern. The same pattern is followed by the equations in questions 3 and 4. Describe this pattern. • A single atom reacts with a compound and replaces one of the atoms in that compound.
How are reactions 5c and 5d different? • Na forms a positive ion (Na+) and replaces another positive ion, but P forms a negative ion (P3-) and replaces another negative ion.
How are reactions 5c and 5d similar? • In both reactions a single atom replaces another atom from a compound that it is reacting with.
NaCl + Ag • AgCl + Na • (note: order is not important, so you could also write Na + AgCl)
Li + Ca3(PO4)2 • Li3PO4 + Ca • (again, order is not important)