College

See the balanced equation below:

[tex]\[ 2 \text{Ga} + 6 \text{HF} \longrightarrow 2 \text{GaF}_3 + 3 \text{F}_2 \][/tex]

[tex]\[
\begin{array}{l|l}
\hline
\text{Substance} & \text{Molar mass (g/mol)} \\
\hline
\text{Ga} & 69.72 \\
\hline
\text{HF} & 20.04 \\
\hline
\text{GaF}_3 & 126.72 \\
\hline
\text{F}_2 & 38.00 \\
\hline
\end{array}
\][/tex]

1. If 250 grams of Ga is present, then how many grams of GaF[tex]\(_3\)[/tex] will be produced?

[Choose]

2. If 314 g of HF is present, then how many grams of GaF[tex]\(_3\)[/tex] will be produced?

[Choose]

3. If 250 grams of Ga and 314 g of HF are present, which one is the limiting reactant?

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4. If this reaction resulted in the production of 100 g of GaF[tex]\(_3\)[/tex], what is the percent yield?

[Choose]

Answer :

Sure! Let's solve this problem step-by-step using the information provided.

### Step 1: Determine Moles of Ga and HF

- Gallium (Ga):
The molar mass of Ga is 69.72 g/mol. We have 250 grams of Ga.
[tex]\[
\text{Moles of Ga} = \frac{250 \, \text{g}}{69.72 \, \text{g/mol}} \approx 3.59 \, \text{moles}
\][/tex]

- Hydrofluoric Acid (HF):
The molar mass of HF is 20.04 g/mol. We have 314 grams of HF.
[tex]\[
\text{Moles of HF} = \frac{314 \, \text{g}}{20.04 \, \text{g/mol}} \approx 15.67 \, \text{moles}
\][/tex]

### Step 2: Reactant to Product Conversion

From the balanced equation, we know:
- 2 moles of Ga produces 2 moles of GaF₃.
- 6 moles of HF produces 2 moles of GaF₃.

- Ga to GaF₃:
Since it's a 1:1 ratio (2 Ga produces 2 GaF₃), the moles of GaF₃ formed from Ga is approximately 3.59 moles.

- HF to GaF₃:
According to the stoichiometry, 3 moles of HF forms 1 mole of GaF₃ (since 6 HF gives 2 GaF₃).
[tex]\[
\text{Moles of GaF}_3 \text{ from HF} = \frac{15.67 \, \text{moles HF}}{3} \approx 5.22 \, \text{moles}
\][/tex]

### Step 3: Identify the Limiting Reactant

The limiting reactant is the one that produces the least amount of product.
- Ga produces approximately 3.59 moles of GaF₃.
- HF could produce about 5.22 moles of GaF₃.

So, Ga is the limiting reactant because it produces less GaF₃.

### Step 4: Calculate Mass of GaF₃ Produced

The moles of GaF₃ that can be formed is limited by Ga: approximately 3.59 moles.
- Molar mass of GaF₃ is 126.72 g/mol.
[tex]\[
\text{Mass of GaF}_3 = 3.59 \, \text{moles} \times 126.72 \, \text{g/mol} \approx 454.39 \, \text{grams}
\][/tex]

### Step 5: Calculate Percent Yield

If 100 grams of GaF₃ were actually produced, we find the percent yield using the formula:
[tex]\[
\text{Percent Yield} = \left( \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \right) \times 100
\][/tex]
[tex]\[
\text{Percent Yield} = \left( \frac{100 \, \text{g}}{454.39 \, \text{g}} \right) \times 100 \approx 22.01\%
\][/tex]

By following these steps, we conclude:
- Mass of GaF₃ produced with 250g of Ga: Approximately 454.39 grams.
- Mass of GaF₃ produced with 314g of HF: HF is not the limiting reactant, remains 454.39 grams.
- Limiting reactant: Ga.
- Percent yield: Approximately 22.01%.