Chemistry
Name:_______________________
balancing and net ionic equations key
Date:__________________
Write the chemical reactions and balance.
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balance charges for all ionic compounds before balancing equation with coefficients
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positive ion always comes first in an ionic compound
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diatomic molecules Br I N Cl H O F, subscript of 2 when alone
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Identify the type of reaction - synthesis, decomposition, combustion, single replacement or
double replacement
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Include state of matter subscripts when possible (s, l, g, aq)
1.
Carbon and oxygen combine to produce carbon monoxide. (synthesis)
2 C(s) + O2 (g) → 2 CO(g)
2. Hydrogen and oxygen combine to produce hydrogen peroxide. (synthesis)
H2 (g) + O2 (g) → H2O2
3. Zinc is replaced in zinc bromide by manganese. Manganese (IV) bromide is produced in this
single displacement reaction.
2 ZnBr2 (aq) + Mn(s) → MnBr4(aq)
+ 2 Zn(s)
4. In solution, potassium bromide combines with barium selenide in a standard double
displacement reaction.
2 KBr(aq) + BaSe → K2Se(aq) + BaBr2 (aq)
5. Barium and fluorine react. There is only one possible product. (synthesis)
Ba(s) + F2 (g) → BaF2
6. Strontium chloride will react with tellurium. There is only one possible set of products in
this single replacement reaction.
SrCl2 (aq) + Te(s) → SrTe(aq) + Cl2 (g)
7. Cesium sulfate reacts with cobalt to form cobalt (III) sulfate. (single replacement)
3 Cs2SO4 (aq) + 2 Co(s) → Co2(SO4)3 (aq) + 6 Cs(s)
8. Zirconium (III) nitrate decomposes, producing zirconium (II) nitride, nitrogen and oxygen.
6 Zr(NO3)3 → 2 Zr3N2 + 7 N2 (g) + 27 O2 (g)
9. Heptane (C7H16) reacts in a classical combustion reaction.
C7H16 (l) + 11 O2 (g) → 7 CO2 (g) + 8 HOH(g)
10. Nitric acid combines with barium hydroxide to produce barium nitrate and water.
(double replacement)
2 HNO3 (aq) + Ba(OH)2 (s) → Ba(NO3)2 (aq) + 2 HOH(l)
Write the full (molecular) equation AND the net ionic equation for the reaction between each of
the following pairs of compounds. Assume both reactants are in solution (aq). If no reaction can
occur, explain why.
11. sodium phosphate and magnesium iodide
2 Na3PO4 (aq) + 3 MgI2 (aq) → 6 NaI(aq) + Mg3(PO4)3(s)
3 Mg2+(aq) + PO43-(aq) → Mg3PO4 (s)
12. sodium carbonate and hydrosulfuric acid
(*remember that carbonic acid (H2CO3) immediately decomposes into carbon dioxide and water)
Na2CO3 (aq) + H2S (aq) → Na2S(aq) + CO2 (g) + HOH(l)
NR – there will be no net ionic equation because sodium sulfide will remain dissolved in water and
carbon dioxide will escape as a gas
13. iron (III) acetate and sodium hydroxide
Fe(C2H3O2)3(aq) + 3NaOH(aq) → Fe(OH)3(s) + 3NaC2H3O2(aq)
Fe3+(aq) + 3 OH-(aq) → Fe(OH)3(s)
14. lead (II) acetate and hydrobromic acid
Pb(C2H3O2)2 (aq) + 2 HBr (aq) → PbBr2(s) + 2 HC2H3O2(aq)
Pb2+(aq) + 2 Br-(aq) → PbBr2 (s)
15. A barium nitrate solution is added to a sodium sulfate solution.
Ba(NO3)2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2 NaNO3(aq)
Ba2+(aq) + SO42-(aq) → BaSO4 (s)