Excess ethanol was soarked with 3g of pure oxygen in a combustion chamber. How many...
Excess ethanol was soarked with 3g of pure oxygen in a combustion chamber. How many molecules of CO2 are produced? [N = 6.02 × 1023 molecules mol_1]
- A) 6.02
- B)3.01
- C) 3.76
- D) 2.84
Correct Answer: C) 3.76
Explanation
To answer this question, we first need to understand the combustion reaction of ethanol. The balanced equation for the combustion of ethanol (C?H?OH) is:
\(C_2H_5OH + 3O_2 \rightarrow 2CO_2 + 3H_2O\)
From the equation, we can see that 1 mole of ethanol reacts with 3 moles of oxygen to produce 2 moles of CO?. The question states that 3g of pure oxygen is used in the reaction. Oxygen has a molar mass of 32g/mol, so we can calculate the moles of oxygen:
\(\text{moles of } O_2 = \frac{3}{32}\)
Now, we can use the stoichiometry of the reaction to find out how many moles of CO? are produced. For every 3 moles of oxygen, 2 moles of CO? are produced. Hence, we can write:
\(\frac{\text{moles of } CO_2}{\text{moles of } O_2} = \frac{2}{3}\)
Substituting the moles of oxygen, we get:
\(\text{moles of } CO_2 = \frac{2}{3} \times \frac{3}{32}\)
After canceling out the 3's, we are left with:
\(\text{moles of } CO_2 = \frac{1}{16}\)
To find the number of CO? molecules, we multiply the moles of CO? by Avogadro's number (N = 6.02