# Help Solving Chemistry Equilibrium Problems Before Test Tomorrow

• DLxX
In summary, the conversation is about a person needing help with chemistry problems and asking for assistance with their test tomorrow. The conversation also includes some of the questions and answers for these problems.

#### DLxX

Ive already done these problems and I think I'm doing them correctly, but I can't be 100% sure since I don't have the answers. Please help if you can since I have my test tommorow. Thanks

Here are some of the questions

1. If 2.6 moles of P4 and 3.6 moles of H2 are reacted till the following equilbirum is established P4 + 6H2 <===> 4PH3 , and if at equilbrium 1.6 moles of PH3 are formed, how many moles of P4 and H2 are in the equilibrium mixture?

(I got .4 and 2.4)

2. At 2000C k=6.2 x 10^-4 for the system N2 + O2 <==> 2NO. How many moles of N2 will exist in equilbrium in a 50 Liter box with .0062 mole of O2 and .0010 mole of NO?

(I got .258 mole)

3. If for the system NH4Cl (s) <=====> NH3 (g) + HCl (g) K=1.0 x 10^-4 . Find the moles of NH3 in a 100 liter container if initially there were 10.0 moles of NH3 added to 10 moles of HCl?

(I got .1)

I got 2.2 and 1.2 moles for P4 and H2, resp. 0.4 and 2.4 moles are really present, but they are reacting amounts of them, so you will subtract these from the beginning amounts, i.e., 2.6 and 3.6 moles, resp.

I don't have enough time to look at the remaining questions, sorry.

1. If 2.6 moles of P4 and 3.6 moles of H2 are reacted till the following equilbirum is established P4 + 6H2 <===> 4PH3 , and if at equilbrium 1.6 moles of PH3 are formed, how many moles of P4 and H2 are in the equilibrium mixture?

I'm not going to check all of your answers for you, you can correspond with the following and ask any questions.

for the first question

$$K= \frac{[2.6moles-x][3.6-6x]^{6}}{[4x]^{4}}$$

## 1. What is chemical equilibrium?

Chemical equilibrium is a state in which the forward and reverse reactions of a chemical reaction occur at the same rate, resulting in no net change in the concentration of reactants and products.

## 2. How do I know if a reaction is at equilibrium?

A reaction is at equilibrium when the concentration of reactants and products remain constant over time. This can be observed through the absence of visible changes or by measuring the concentration of reactants and products over time.

## 3. How do I solve equilibrium problems?

To solve equilibrium problems, you must first write the balanced chemical equation and determine the equilibrium constant, K. Then, use the initial concentrations of reactants and products to set up an ICE (Initial, Change, Equilibrium) table. Finally, use the equilibrium constant expression and the values from the ICE table to solve for the unknown concentrations.

## 4. What is Le Chatelier's principle and how does it apply to equilibrium problems?

Le Chatelier's principle states that when a stress is applied to a system at equilibrium, the system will shift in a way that minimizes the effect of the stress. In equilibrium problems, this means that changes in temperature, pressure, or concentration can cause the system to shift in a direction that either increases or decreases the concentration of reactants or products in order to maintain equilibrium.

## 5. How can I prepare for a chemistry equilibrium test?

To prepare for a chemistry equilibrium test, make sure you understand the concepts and principles involved in equilibrium. Practice solving equilibrium problems and familiarize yourself with common types of equilibrium reactions. Additionally, create study aids such as flashcards or summary sheets to help you review important information. Finally, get plenty of rest and arrive to the test well-prepared and confident.