Question

4) When an element burns in oxygen gas, the product is called an oxide. a. The wood in the splint consists mostly of carbon. The combustion of carbon produces carbon dioxide, CO2. Write the equation for the combustion of wood (carbon). Word Equation: Balanced Formula Equation: b. The combustion of sulfur produces sulfur dioxide, SO2. Write the equation for the combustion of sulfur. Word Equation: Balanced Formula Equation: c. Steel wool consists mostly of iron. The combustion of iron produces iron(III) oxide, Fe2O3. Write the equation for the combustion of steel wool (iron). Word Equation: Balanced Formula Equation: d. The combustion of hydrogen produces water, H2O. Write the equation for the combustion of hydrogen. Word Equation: Balanced Formula Equation: e. The combustion of magnesium produces magnesium oxide, MgO. Write the equation for the combustion of magnesium. Word Equation: Balanced Formula Equation:

Answer 1

a. Write the equation for the combustion of wood (carbon).

C + O₂ -----> CO₂ (balanced)

b. Write the equation for the combustion of sulfur.

S + O₂ -----> SO₂ (balanced)

c. Write the equation for the combustion of steel wool (iron):

Fe + O₂ -----> Fe₂O₃ (unbalanced)

To balance any equation we have to count the amount of each element that we have on each side. If we take a look at the equation we will see that we have 2 atoms of O and 1 atom of Fe on the left side of the equation and 3 atoms of O and 2 atoms of Fe on the right side.

___ Fe + ___ O₂ -----> ____ Fe₂O₃

O: 2 O: 3

Fe: 1 Fe: 2

If we want to balance the O we will have to change two coefficients. The coefficient in front of O₂ must be a 3 and the coefficient in front of Fe₂O₃ must be a 2.

___ Fe + 3 O₂ -----> 2 Fe₂O₃

O: 6 O: 6

Fe: 1 Fe: 4

We balanced the balanced the O with those changes but we also changed the amount of Fe that we have on the right side. Now we have 4 atoms of Fe. To balance it we have to change the coefficient in front of Fe and put a 4 there.

4 Fe + 3 O₂ -----> 2 Fe₂O₃

O: 6 O: 6

Fe: 4 Fe: 4

Now the equation is balanced.

4 Fe + 3 O₂ -----> 2 Fe₂O₃ (balanced)

d. Write the equation for the combustion of hydrogen.

H₂ + O₂ ------> H₂O (unbalanced)

2 H₂ + O₂ -----> 2 H₂O (balanced)

e. Write the equation for the combustion of magnesium.

Mg + O₂ -----> MgO (unbalanced)

2 Mg + O₂ -----> 2 MgO (balanced)