Chapter 6: Chemical Reactions

Identify redox reactions.

Identify and write equations for combustion reactions.

A reaction can be classified as a redox reaction if it meets any one of these requirements. A substance reacts with elemental oxygen

(combustion).

A metal reacts with a nonmetal.

During single displacement reactions.

More generally, one substance transfers electrons to another substance.

2Na(s) + Cl2(g) 2NaCl(s) Na + Cl Na+ + Cl-

e-

Combustion reactions are a type of redox reaction.

Combustion reactions are characterized by the reaction of a substance with O2 to form one or more oxygen-containing compounds, often including water.

Combustion reactions are exothermic (they emit heat).

Compounds containing carbon and hydrogen always form carbon dioxide and water upon combustion.

CH4(g) + O2(g)

2Mg(s) + O2(g) 2MgO(s)

Mg + O Mg2+ + O2-

e- e-

2Al(s) + Fe2O3(s) 2Fe(s) + Al2O3(s)

Al + Fe3+ Fe + Al3+

e- e- e-

For each reaction, show how electrons are gained and lost:

2Na (s) + Br2(l) 2NaBr (s)

2Ca (s) + O2(g) 2CaO (s)

Predict the products for the following combustion reactions:

C6H14(l) + O2(g)

Cu(s) + O2(g)

Classify each of the following reactions in as many ways possible.

2K (s) + Cl2(g) 2KCl (s)

2Mg (s) + O2(g) 2MgO (s)

Classify each of the following reactions in as many ways possible.

Fe2O3(s) + 2Al(s) Al2O3(s) + 2Fe(s)

HNO3(aq) + NaOH(aq) → H2O(l) + NaNO3 (aq)

Ba(NO3)2(aq) + (NH4)2SO4(aq)

HCl(aq) + KOH(aq)

Na(s) + Cl2(g)

FeCl3(aq) + NaOH(aq)

Zn(s) + HNO3(aq)

C6H14(l) + O2(g)

CuSO4(aq) + Na2CO3(aq)

HClO4(aq) + NaOH(aq)

NI3(s)

ZnCl2(aq) + Mg(s)

H2SO4(aq) + Ba(OH)2(aq)

KNO3(aq) + BaCl2(aq)