11-4 Homework 1) Nickel (II) Phosphate2) Silver bromide3) Tin (IV) chloride 4) Ammonium sulfide5) Mercury (II) fluoride6) Magnesium nitride 7) Bismuth iodide8) Ammonium sulfate 9) Zinc carbonate10)Copper (I) sulfide

11/4 Homework: 1) Ni3(PO4)2 6) Mg3N2

2) AgBr 7) BiI33) SnCl4 8) (NH4)2 SO4

4) (NH4)2 S 9) ZnCO3

5) HgF2 10) Cu2S

Chemical Equations ! !

Law of Conservation of Matter:

Matter cannot be created or destroyed.

AMOUNT OF REACTANTS = AMOUNT OF PRODUCTS ! ! ! !

Guidelines for Balancing Chemical

Equations:  1) Do NOT change the subscripts ! 2) Every element MUST have the same amount of atoms

on both sides of the equation. 3) To balance, coefficients (numbers) are added in front

of the chemical formula until we have the same atom amount on both sides of the equation.

4) Once a coefficient is added, go back and check the rest of the equation

5) Balance every element EXCEPT Hs and Os. Then balance Hs, Os are balanced last. Balance Hs with an EVEN number

6) CHECK EQUATION TO BE SURE EVERYTHING BALANCES/CANCELS OUT ON BOTH SIDES ! ! !

Example 1:

Mg + HCl è MgCl2 + H2

Example 2:

KI (aq) + Pb(NO3)2 è KNO3 + PbI2

Example 3:

FeI3 + K2SO4 è KI + Fe2(SO4)3

Practice 1) Zn + CrCl3 è CrCl2 + ZnCl2  2) Cu + H2SO4 è CuSO4 + SO2 + H2O

3) LiAlH4 + H2O è LiOH + Al(OH)3 + H2

  4) CaSO4 + Al(NO3)3 è Ca(NO3)2 + Al2(SO4)3

Homework

Worksheet on Balancing Equations