Contents

- 1 What is the equilibrium constant for FeSCN2+?
- 2 What is the KC value for FeSCN2+?
- 3 What is the value of equilibrium constant k?
- 4 What is the extinction coefficient of Fe SCN 2+ in this experiment?
- 5 What is the equilibrium constant expression for the reaction?
- 6 What is the equilibrium constant for the reaction between iron III and thiocyanate ions?
- 7 How do you calculate FeSCN2+ EQ?
- 8 How do you find equilibrium constant from absorbance?
- 9 How do you calculate KC?
- 10 What does equilibrium constant mean?
- 11 What does the equilibrium constant depend on?
- 12 What does a very small equilibrium constant K ≪ 1 tell you about the reaction?
- 13 How do you find the initial concentration of Fe3+ and SCN?
- 14 How do you calculate molar absorptivity?
- 15 What is the molar absorptivity of FeSCN2+?

## What is the equilibrium constant for FeSCN2+?

By spectroscopy and Beer’s Law, it is found that [**FeSCN2+**] at **equilibrium** is 1.50 x 10-4 M.

## What is the KC value for FeSCN2+?

The absorbance of this solution is measured, and the equilibrium **FeSCN2+**(aq) concentration is found to be 1.0 × 10 –3 M. Determine the **value** of **Kc**. = 40. One point is earned for the correct equilibrium concentration.

## What is the value of equilibrium constant k?

The **equilibrium constant value** is the ratio of the concentrations of the products over the reactants. This means that we can use the **value** of **K** to predict whether there are more products or reactants at **equilibrium** for a given reaction.

## What is the extinction coefficient of Fe SCN 2+ in this experiment?

At the wavelength of maximum absorbance, λmax, the molar **extinction coefficient**, ε, for the product, **Fe**(**SCN**)**2**+, is 6120 M-1cm-1.

## What is the equilibrium constant expression for the reaction?

For gases, the equilibrium constant expression can be written as the ratio of the partial pressures of the products to the partial pressures of the reactants, each raised to a power matching its **coefficient** in the chemical equation.

## What is the equilibrium constant for the reaction between iron III and thiocyanate ions?

It has an **equilibrium constant**, K, given by: The FeSCN^{2}^{+} complex that is formed as a result **of reaction between iron**(**III) and thiocyanate ions** has a very intense blood red color (or orange in dilute solution), allowing for easy detection and quantitative determination by spectrophotometry.

## How do you calculate FeSCN2+ EQ?

[**FeSCN ^{2}^{+}**]

**is**

_{eq}**calculated**using the

**formula**: where A

**and A**

_{eq}_{std}are the absorbance values for the equilibrium and standard test tubes, respectively, and [

**FeSCN**]std = (1/10)(0.0020) = 0.00020 M.

^{2}^{+}**Calculate**[

**FeSCN**]

^{2}^{+}**for each of the four trials. 7.**

_{eq}## How do you find equilibrium constant from absorbance?

X = [Fe(SCN)2+] and is to be determined from the standard curve. You can then **calculate** the **equilibrium constant**, Keq, using the **equilibrium** concentrations. The standard curve is a plot of **Absorbance** versus [Fe(SCN)2+] (Figure 8.1). It can be used to give us the concentration of a solution when given the **absorbance**.

## How do you calculate KC?

For the reaction A+B=AB, the equilibrium constant **Kc** is defined as [AB]/[A][B]. Brackets denote reagent concentrations that must be given in order to **compute Kc**. As an example, we will **calculate Kc** for two reactions.

## What does equilibrium constant mean?

: a number that expresses the relationship between the amounts of products and reactants present at **equilibrium** in a reversible chemical reaction at a given temperature.

## What does the equilibrium constant depend on?

As detailed in the above section, the position of **equilibrium** for a given reaction **does** not **depend on** the starting concentrations and so the value of the **equilibrium constant** is truly **constant**. It **does**, however, **depend on** the temperature of the reaction.

## What does a very small equilibrium constant K ≪ 1 tell you about the reaction?

A **small equilibrium constant**, or when **K**_{eq} is less than **one**, means that the chemical **reaction** will favor the reactants and the **reaction** will proceed in the opposite direction. An **equilibrium constant** of **1** indicates that the reactants and products will be equal when the **reaction** reaches **equilibrium**.

## How do you find the initial concentration of Fe3+ and SCN?

– To **find** the **initial concentration** of **SCN**–, use the dilution **equation**: (M1V 1)/V 2 = M2, where V2 = 10 mL. – To **find** the **initial concentration of Fe3+**, use the dilution **equation**: (M1V 1)/V 2 = M2, where V2 = 10 mL.

## How do you calculate molar absorptivity?

Using the values you obtained for A, c, and l, plug them into the equation ɛ = A/lc. Multiply l by c and then divide A by the product to solve for **molar absorptivity**. For example: Using a cuvette with a length of 1 cm, you measured the absorbance of a solution with a concentration of 0.05 mol/L.

## What is the molar absorptivity of FeSCN2+?

Frank and Oswalt report a **molar absorptivity** (ε) for **FeSCN2+** of 4700L/(mol*cm). Remember that your pathlength (b) is 1 cm for the Spec-20.