Question

What is the mass of `CO2` formed when 1.00kJ of energy is released? Full question in the description box below as an image.

Answer 1

The mass of `"CO"_2` formed is 129 mg.

Explanation:

Step 1. Write the balanced equation for the reaction

`"C"_2"H"_5"OH" + "3O"_2 → "2CO"_2 + "3H"_2"O"; Δ_text(c)H = "-1366.3 kJ·mol"^"-1"`

Step 2. Calculate the moles of `"CO"_2` formed

`n_text(CO₂) = 1.00 color(red)(cancel(color(black)("kJ"))) × (1 color(red)(cancel(color(black)("mol C"_2"H"_5"OH"))))/(1366.3 color(red)(cancel(color(black)("kJ"))))× ("2 mol CO"_2)/(1 color(red)(cancel(color(black)("mol C"_2"H"_5"OH")))) = "0.001 464 mol CO"_2`

Step 3. Calculate the mass of `"CO"_2` formed

#m_text(CO₂) = "0.001 464" color(red)(cancel(color(black)("mol CO"_2))) × "44.01 g CO"_2/(1 color(red)(cancel(color(black)("mol CO"_2)))) = "0.0644 g CO"_2 = "64.4 mg CO"_2#