
Answer: Â
4.3 g
Explanation: Â
We know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place. Â
M_r: Â Â Â Â Â Â Â 60.05 Â Â Â 32.00
         CH₃CH₂OH + 3O₂ ⟶ 2CO₂ + 3H₂O
Mass/g: Â Â Â Â Â Â Â Â Â Â Â Â Â Â 7.0 Â
1. Calculate the moles of Oâ‚‚
Moles Oâ‚‚ = 7.0 × 1/32.00 Â
Moles Oâ‚‚ = 0.219 mol Oâ‚‚ Â
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2. Calculate the moles of CH₃CH₂OH
The molar ratio is 1 mol CH₃CHâ‚‚OH:3 mol Oâ‚‚ Â
Moles of CH₃CHâ‚‚OH = 0.219 × 1/3 Â
Moles of CH₃CH₂OH = 0.0729 mol CH₃CH₂OH
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3. Calculate the mass of CH₃CHâ‚‚OH Â
Mass of CH₃CH₂OH = 0.0729 × 60.05
Mass of CH₃CH₂OH = 4.4 g