P 8.4 (pg 1 of 2)
Synthesis Reactions (aka Combination Reactions)
Write correct skeleton equations for these synthesis reactions, then balance. Pay attention to substances that react with water, the
product will usually be dissolved in water. Unless you are told that a substance is a liquid or gas, assume that it is a solid. Label
the reaction as redox or not.
1.
Magnesium chloride and oxygen gas react.
2.
Sodium and oxygen gas react
3.
Solid diphosphorus pentoxide combine with liquid water to produce aqueous phosphoric acid (one of those six acids you
have been asked to memorize.)
4.
Aqueous potassium hydroxide is the product of the synthesis of potassium oxide and liquid water.
5.
Barium oxide reacts with gaseous carbon dioxide.
6.
Aluminum oxide reacts with gaseous carbon dioxide
7.
Aqueous nitric acid is the product of the combination of gaseous dinitrogen pentoxide and water.
8.
Sodium chloride and oxygen gas react.
9.
Radium and chlorine gas react.
10. Aluminum oxide combines with liquid water to produce aqueous aluminum hydroxide.
P 8.4 (pg 2 of 2)
Synthesis Reactions (aka Combination Reactions)
ANSWERS
1.
skeleton:
balanced:
MgCl2(s) + O2(g) → Mg(ClO3)2(s)
MgCl2(s)
+ 3 O2(g)
→ Mg(ClO3)2(s)
redox
2.
skeleton:
balanced
Na(s)
+ O2(g)
4 Na(s)
+ O2(g)
redox
3.
skeleton:
balanced
P2O5(s)
P2O5(s)
4.
skeleton:
balanced
K2O(s) + H2O(L)
K2O(s) + H2O(L)
5.
skeleton:
balanced
BaO(s) + CO2(g)
already balanced
6.
skeleton:
balanced
Al2O3(s)
Al2O3(s)
7.
skeleton:
balanced
N2O5(g) + H2O(L)
N2O5(g) + H2O(L)
8.
skeleton:
balanced
NaCl(s) + O2(g)
2 NaCl(s) + 3 O2(g)
→ NaClO3(s)
→ 2 NaClO3(s)
9.
skeleton:
balanced
Ra(s)
+ Cl2(g)
already balanced
→ RaCl2(s)
10. skeleton:
balanced
Al2O3(s)
Al2O3(s)
→ Na2O(s)
→ 2 Na2O(s)
+ H2O(L)
+ 3 H2O(L)
→ H3PO4
→ 2 H3PO4
→ KOH(aq)
→ 2 KOH(aq)
→ BaCO3(s)
+ CO2(g)
+ 3 CO2(g)
→ Al2(CO3)3(s)
→ Al2(CO3)3(s)
→ HNO3(aq)
→ 2 HNO3(aq)
+ H2O(L)
→ Al(OH)3(aq)
+ 3 H2O(L) → 2 Al(OH)3(aq)
not redox
not redox
not redox
not redox
not redox
redox
redox
not redox