Download Chemical Equations

Name: ________________________________ Hr. ___ Date: ______________________
Chemical Equations
A CHEMICAL EQUATION is a way of
representing a chemical reaction on paper.
These numbers are found in chemical
equation:
SUBSCRIPTS: The small numbers to the
lower right of chemical symbols and formulas,
that represent the number of atoms/ions in that element in the compound.
These are NOT TO BE CHANGED after the skeleton equation has been
written.
COEFFICIENTS: The large numbers in front of chemical formulas.
Coefficients are used to balance a chemical equation. Coefficients represent
the relative number of molecule/formula units of the substance in the
reaction.
!!!!!!!!Never balance an equation by changing SUBSCRIPTS!!!!!!!
Balancing By Inspection
Use the following steps, in order, to help you balance a
skeleton equation……
1. Check for diatomic molecules H2 N2 O2 F2 Cl2 Br2 I2
If these elements appear by themselves in an equation, they
must be written with subscript 2
2. Balance the metals
3. Balance non-metals (other than oxygen)
4. Balance oxygen (unless present in 2 or more places on a side, if
it is, then it moves to the “end of the line”)
5. Balance hydrogen
6. Recount all atoms
If the atoms are not balanced at this point, there is a problem
somewhere, generally one of the compound formulas is not
written correctly, go back and check all formulas for
accuracy.
7. If every coefficient will reduce, rewrite in the simplest wholenumber ratio.
Name: ________________________________ Hr. ___ Date: ______________________
Identify the type of reaction shown (Syn, Dec, SR, DR, Comb), then
balance each using the tips on the front side.
______1. ___SrBr2 + ___ (NH4)2CO3  ___ SrCO3 +___NH4Br
______2.
___Au2O3 
______3. ___SiC
+
___Au
___Cl 
+
___O
___SiCl4 +
___C
______4. ___Na2SiO3 + ___HCl  ___NaCl
______5. ___ C7H16 + ___O

___CO2
+ ___H2SiO3
+
___H2O
______6. ___(NH4)2Cr2O7 ___NH3+___H2O+ ___Cr2O3+ ___O
______7.
___Pb(NO3)2  ___PbO +___NO2 + ___O
______8. ___V2O5 + ___HCl
 ___VOCl3
+
___H2O
______9. ___Mg(OH)2 + ___H3PO4  ___ Mg3(PO4)2 + ___H2O
_XXX_10. ___Br_ + ___H2O + ___SO2  ___HBr +___H2SO4
Rewrite as skeleton equation, then balance
11. sodium hydroxide decomposes to produce sodium oxide and
water
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12. iron plus oxygen gas produces iron (III) oxide
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13. aluminum nitrate plus sulfuric acid produces…….(complete)
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Name: ________________________________ Hr. ___ Date: ______________________