Answer key for calculating molar mass of elements and compounds, useful for chemistry students.

To solve the problem of determining the molar mass of the given compounds, we need to use the atomic masses of the elements provided in the table. Let's go through each compound step by step.

Step 1: Understand the Problem

We are tasked with calculating the molar mass of various compounds using the atomic masses of the elements listed in the table. The molar mass of a compound is the sum of the atomic masses of all the atoms in its molecular formula.

Step 2: Use the Atomic Masses

The atomic masses of the elements are given in the table:
- Nitrogen (N): 14.01 g/mol
- Phosphorus (P): 30.97 g/mol
- Sulfur (S): 32.07 g/mol
- Titanium (Ti): 47.88 g/mol
- Yttrium (Y): 88.91 g/mol
- Zinc (Zn): 65.38 g/mol
- Hydrogen (H): 1.008 g/mol
- Tellurium (Te): 127.60 g/mol
- Iodine (I): 126.90 g/mol
- Xenon (Xe): 131.29 g/mol
- Gold (Au): 196.97 g/mol

Step 3: Calculate the Molar Mass of Each Compound

We will calculate the molar mass for each compound listed in the problem.

#### 1. N₂
- Formula: \( \text{N}_2 \)
- Molar mass = \( 2 \times 14.01 \, \text{g/mol} = 28.02 \, \text{g/mol} \)

#### 2. NH₃
- Formula: \( \text{NH}_3 \)
- Molar mass = \( 1 \times 14.01 \, \text{g/mol} + 3 \times 1.008 \, \text{g/mol} = 14.01 + 3.024 = 17.034 \, \text{g/mol} \)

#### 3. NO₂
- Formula: \( \text{NO}_2 \)
- Molar mass = \( 1 \times 14.01 \, \text{g/mol} + 2 \times 16.00 \, \text{g/mol} = 14.01 + 32.00 = 46.01 \, \text{g/mol} \)

#### 4. P₄O₁₀
- Formula: \( \text{P}_4\text{O}_{10} \)
- Molar mass = \( 4 \times 30.97 \, \text{g/mol} + 10 \times 16.00 \, \text{g/mol} = 123.88 + 160.00 = 283.88 \, \text{g/mol} \)

#### 5. SO₃
- Formula: \( \text{SO}_3 \)
- Molar mass = \( 1 \times 32.07 \, \text{g/mol} + 3 \times 16.00 \, \text{g/mol} = 32.07 + 48.00 = 80.07 \, \text{g/mol} \)

#### 6. TiCl₄
- Formula: \( \text{TiCl}_4 \)
- Molar mass = \( 1 \times 47.88 \, \text{g/mol} + 4 \times 35.45 \, \text{g/mol} = 47.88 + 141.80 = 189.68 \, \text{g/mol} \)

#### 7. Y₂(SO₄)₃
- Formula: \( \text{Y}_2(\text{SO}_4)_3 \)
- Molar mass = \( 2 \times 88.91 \, \text{g/mol} + 3 \times (1 \times 32.07 \, \text{g/mol} + 4 \times 16.00 \, \text{g/mol}) \)
- Molar mass = \( 177.82 + 3 \times (32.07 + 64.00) = 177.82 + 3 \times 96.07 = 177.82 + 288.21 = 466.03 \, \text{g/mol} \)

#### 8. Zn(NO₃)₂
- Formula: \( \text{Zn(NO}_3)_2 \)
- Molar mass = \( 1 \times 65.38 \, \text{g/mol} + 2 \times (1 \times 14.01 \, \text{g/mol} + 3 \times 16.00 \, \text{g/mol}) \)
- Molar mass = \( 65.38 + 2 \times (14.01 + 48.00) = 65.38 + 2 \times 62.01 = 65.38 + 124.02 = 189.40 \, \text{g/mol} \)

#### 9. H₂Te
- Formula: \( \text{H}_2\text{Te} \)
- Molar mass = \( 2 \times 1.008 \, \text{g/mol} + 1 \times 127.60 \, \text{g/mol} = 2.016 + 127.60 = 129.616 \, \text{g/mol} \)

#### 10. XeF₄
- Formula: \( \text{XeF}_4 \)
- Molar mass = \( 1 \times 131.29 \, \text{g/mol} + 4 \times 19.00 \, \text{g/mol} = 131.29 + 76.00 = 207.29 \, \text{g/mol} \)

#### 11. AuI₃
- Formula: \( \text{AuI}_3 \)
- Molar mass = \( 1 \times 196.97 \, \text{g/mol} + 3 \times 126.90 \, \text{g/mol} = 196.97 + 380.70 = 577.67 \, \text{g/mol} \)

Final Answer

\[
\boxed{
\begin{array}{ll}
1. \text{N}_2 & 28.02 \, \text{g/mol} \\
2. \text{NH}_3 & 17.034 \, \text{g/mol} \\
3. \text{NO}_2 & 46.01 \, \text{g/mol} \\
4. \text{P}_4\text{O}_{10} & 283.88 \, \text{g/mol} \\
5. \text{SO}_3 & 80.07 \, \text{g/mol} \\
6. \text{TiCl}_4 & 189.68 \, \text{g/mol} \\
7. \text{Y}_2(\text{SO}_4)_3 & 466.03 \, \text{g/mol} \\
8. \text{Zn(NO}_3)_2 & 189.40 \, \text{g/mol} \\
9. \text{H}_2\text{Te} & 129.616 \, \text{g/mol} \\
10. \text{XeF}_4 & 207.29 \, \text{g/mol} \\
11. \text{AuI}_3 & 577.67 \, \text{g/mol} \\
\end{array}
}
\]