College

When a mixture of 58.0 g of acetylene, [tex]C_2H_2[/tex], and 81.0 g of oxygen, [tex]O_2[/tex], is ignited, the resultant combustion reaction produces [tex]CO_2[/tex] and [tex]H_2O[/tex].

For this combustion reaction, the limiting reactant is and the yield of [tex]CO_2[/tex] is:

A. [tex]O_2, 44.0 \, \text{g}[/tex]

B. [tex]C_2H_2, 49.1 \, \text{g}[/tex]

C. [tex]O_2, 196 \, \text{g}[/tex]

D. [tex]O_2, 89.1 \, \text{g}[/tex]

E. [tex]C_2H_2, 98.2 \, \text{g}[/tex]

Answer :

Sure, let's solve this step-by-step!

The balanced combustion reaction for acetylene ([tex]$C_2H_2$[/tex]) with oxygen ([tex]$O_2$[/tex]) is as follows:

[tex]\[ 2 C_2H_2 + 5 O_2 \rightarrow 4 CO_2 + 2 H_2O \][/tex]

Here's the step-by-step process:

1. Determine the masses and molar masses:
- Mass of [tex]$C_2H_2$[/tex]: 58.0 g
- Mass of [tex]$O_2$[/tex]: 81.0 g

The molar masses are:
- Molar mass of [tex]$C_2H_2$[/tex]: 26.04 g/mol
- Molar mass of [tex]$O_2$[/tex]: 32.00 g/mol

2. Calculate the moles of each reactant:
- Moles of [tex]$C_2H_2$[/tex]:
[tex]\[ \frac{58.0 \text{ g}}{26.04 \text{ g/mol}} = 2.228 \text{ mol} \][/tex]

- Moles of [tex]$O_2$[/tex]:
[tex]\[ \frac{81.0 \text{ g}}{32.00 \text{ g/mol}} = 2.531 \text{ mol} \][/tex]

3. Use stoichiometric coefficients from the balanced equation:
- For [tex]$C_2H_2$[/tex]: 2 moles are required.
- For [tex]$O_2$[/tex]: 5 moles are required.

4. Determine which reactant is the limiting reactant:

Find the moles of [tex]$O_2$[/tex] required to completely react with the given moles of [tex]$C_2H_2$[/tex]:
[tex]\[ \text{Moles of } O_2 = 2.228 \text{ mol} \times \frac{5 \text{ mol } O_2}{2 \text{ mol } C_2H_2} = 5.57 \text{ mol } O_2 \][/tex]

Compare this with the available moles of [tex]$O_2$[/tex]:
- Available moles of [tex]$O_2$[/tex]: 2.531 mol

Since the required moles of [tex]$O_2$[/tex] (5.57 mol) are more than the available moles (2.531 mol), [tex]$O_2$[/tex] is the limiting reactant.

5. Calculate the yield of [tex]$CO_2$[/tex]:

Using the limiting reactant ([tex]$O_2$[/tex]):

[tex]\[ \text{Yield of } CO_2 = \frac{2.531 \text{ mol } O_2}{5} \times 4 \times 44.01 \text{ g/mol} \][/tex]

Simplify the expression:

[tex]\[ \text{Yield of } CO_2 = 2.0248 \text{ mol } \times 44.01 \text{ g/mol} \][/tex]
[tex]\[ \text{Yield of } CO_2 = 89.1 \text{ g} \][/tex]

Thus, the limiting reactant is [tex]$O_2$[/tex] and the yield of [tex]$CO_2$[/tex] is 89.1 g. Therefore, the correct answer is:

[tex]\[ O_2, 89.1 \, \text{g} \][/tex]