Question

The Determination of an Equilibrium Constant Pre-lab Questions equation CV =CV experiment, mol of SCN or the solutions that you will prepare in Step 7 of Part I. calculate the (FeSCN1 using the CV CV. Presume that all of the SCN ions react and therefore in Part I of the el mol of SCN=mol of FeSCN. Record these values in the table below and in the dala table for part / Standard solution. Beaker number [FeSCN2) Alo N- 2. Define equilibrium constant Ke. 3. Write the equilibrium constant expressions for each of the following chemical reactions a) CHOH (9) CO(g) + 2H; (g) b) CsHs (g) +502 (g) + 3C02 (g) + 4H:0 (g) c) N2(g) + O2 (g) + 2NO(g) 4. For each of the following values of K, indicate whether the forward reaction, reverse reaction. or neither would be favored. a. Key = 3.7 x 10$ (K>>>I) b. Key = 4.1 x 10°(K<<<I) c. Keq = 1.47 (K-1)

Answer 1

2.

Equilibrium constant gives the relationship between the amount of product and reactant present at a given temperature for a reversible reaction.

If the equilibrium constant is more than 1, then the reaction favours the product side, and if it is less than 1, then the reactants are favoured.

3.

To write the expression for equilibrium constant:

For the general reaction:

aA + bB <-> cC + dD ,

where a,b,c and d are the stoichiometric coefficients, A and B are reactants and C and D are products;

K_eq =

c]CID]d [Aja[в]Ь b

Only compounds in gaseous (g) or aqueous (aq) state are included in the expression.

[…] denotes concentration

So, writing the expression :

3.

a)

K_eq =

[co] [н,1? [сн, он] CH

b)

K_eq =

[co,]3 [н, о1 [c, Hа] [о,1s 5

c)

K_eq =

[No]2

4.

As mentioned in the definition, a if equilibrium constant is more than 1, the reaction favours the products, i.e the forward direction, and vice versa. So the answers are:

a)

forward reaction

b)

reverse reaction

c)

neither