In this reaction, how many grams of O2 are required to completely react with 110 grams of Al

98 g

Explanation:

Start with the balanced equation. Then, make a little chart under the equation showing the information you have and need.

        3O₂(g) + 4Al(s)  →  2Al₂O₃(s)

m        ?           110 g

M      ___       ____

n       ___ <=  ____

"m" is for mass. "M" is for molar mass (some teachers use "MM"). "n" is for the number of moles.

To find the mass of oxygen:

To find molar mass, use the atomic mass on your periodic table. For each atom of an element, add on its atomic mass.

Molar mass of aluminum (one Al atom):

Molar mass of oxygen (two O atoms):

Update the chart:

               3O₂(g)       +          4Al(s)          →     2Al₂O₃(s)

m                ?                        110 g

M      32.000 g/mol       26.982 g/mol

n                ___         <=      ____

Find the moles of aluminum

   Multiply mass by molar mass to find moles.

      The units "g" cancel out.

       Keep one extra significant figure. (110 has 2 sig. figs.)

               3O₂(g)       +          4Al(s)          →     2Al₂O₃(s)

m                ?                        110 g

M      32.000 g/mol       26.982 g/mol

n                ___         <=   4.0(7) mol

Find the moles of oxygen using the mole ratio, which comes from the coefficients in the balanced equation.

The mole ratio of oxygen to aluminum is 3 to 4.

    Multiply moles of aluminum by the mole ratio.

            "molAl" units cancel out.

             Keep two sig. figs. when the first is a "5"

               3O₂(g)       +          4Al(s)          →     2Al₂O₃(s)

m                ?                        110 g

M      32.000 g/mol       26.982 g/mol

n          3.0(52) mol   <=    4.0(7) mol

Find the mass of oxygen

       Multiply moles by molar mass.

            The "mol" unit cancels out.

                        Keep one sig. fig. to round. "6" rounds up.

                              <= Final answer

∴ 98 grams of oxygen are required to completely react with 110 grams of aluminum.

the movie was based there, and all the animals and characters are native.

~courtney