Question

iron(iii) thiocyanate spectroscopy
dilution
iron(iii) reacts with scn⁻ to form a deep red-colored complex ion.
fe³⁺ scn⁻ fescn²⁺
for a spectrophotometry experiment, a student generates a standard curve using a 0.1000 m iron thiocyanate fescn²⁺ solution.
the student creates four more fescn²⁺ solutions of known concentrations: 0.0800 m, 0.0600 m, 0.040 m, and 0.0020 m are made in 100.00 ml volumetric flasks.
calculate the volume of 0.1000 m fescn²⁺ required to make 100.00 ml of 0.0600 m fescn²⁺.
what volume of 0.1000 m fescn⁻ is needed to make 100.00 ml of 0.0600 m fescn⁻?
40.0 ml
60.0 ml
0.400 l
0.600 l

Explanation:

Step1: Recall dilution formula

The dilution formula is $C_1V_1 = C_2V_2$, where $C_1$ is initial concentration, $V_1$ is initial volume, $C_2$ is final concentration, $V_2$ is final volume.

Step2: Identify known values

$C_1 = 0.1000\ \text{M}$, $C_2 = 0.0600\ \text{M}$, $V_2 = 100.00\ \text{mL}$

Step3: Solve for $V_1$

Rearrange formula: $V_1 = \frac{C_2V_2}{C_1}$
Substitute values: $V_1 = \frac{0.0600\ \text{M} \times 100.00\ \text{mL}}{0.1000\ \text{M}} = 60.0\ \text{mL}$

Answer:

60.0 mL