# Question #3dd04

##### 2 Answers

#### Answer:

37.

38.

#### Explanation:

37.

First off, you should write the equilibrium expression for the reaction. You should get:

Then you just plug in the given concentrations to find out if the reaction is at equilibrium. If the formula equals 85.0 (the equilibrium constant), then the reaction is at equilibrium.

*Note: #Q# is what you use when you are unsure if the system is at equilibrium. Otherwise, you use #K#.*

If

38.

This question is similar to 37. The first step would be to convert the given moles of

Then you set up an ICE chart to find the other values at equilibrium.

Initial:

Change:

Equilibrium:

*Note: #x# is just a variable. The coefficient before #x# is based on the reaction coefficients.*

Now you just solve for

Then you just imput those values into the

Since you only have 3 significant figures, the answer would be:

39.

This one is almost exactly the same as 38. The only difference is that when you make your ICE chart, the coefficients for

~Hope this helps!

#### Answer:

37 (a)The reaction is not at equilibrium; (b) The reaction will have to proceed to the left to reach equilibrium. 38

#### Explanation:

**37**. Start by writing the chemical equation with the concentrations beneath the formulas.

Next. write the equilibrium constant expression (remember, "products over reactants"):

Insert the concentrations into this expression.

**(a)** We know that **not** at equilibrium.

**(b)** The number is bigger than

To get to equilibrium, the reaction must get rid of some of the products.

The reaction will shift **to the left**.

**38** For this problem, we can set up an ICE table.

The initial concentration of

The initial concentrations of

We don't know how much hydrogen and bromine will form, but we know it will be some unknown value,

We also know that, for every mole of hydrogen and bromine formed, 2 mol of

We put all this into the ICE table and get

We are told that the equilibrium concentration of

∴

The equilibrium concentrations are then

Now, we insert these concentrations into the equilibrium constant expression: