Question

iron(iii) thiocyanate spectroscopy
percent composition
calculate the percent composition of iron in
fescn²⁺.
what is the percent composition of fe in
fescn²⁺?
about 0.558%
about 49.0%
about 0.490%
about 55.8%

Explanation:

Step1: Find molar masses of elements

Molar mass of Fe: $55.85\ \text{g/mol}$
Molar mass of S: $32.07\ \text{g/mol}$
Molar mass of C: $12.01\ \text{g/mol}$
Molar mass of N: $14.01\ \text{g/mol}$

Step2: Calculate total molar mass of ion

$$55.85 + 32.07 + 12.01 + 14.01 = 113.94\ \text{g/mol}$$

Step3: Compute percent composition of Fe

$$\text{Percent Fe} = \frac{\text{Molar mass of Fe}}{\text{Total molar mass}} \times 100\% = \frac{55.85}{113.94} \times 100\% \approx 49.0\%$$

Answer:

about 49.0%