CHEMISTRY COMMUNITY

Phuong Tran 1G

Are we responsible for memorizing strong scids and bases and weak acids and bases?

Phuong Tran 1G

In an experiment, 0.020 mol NO was introduced into a 2 flask of volume 1.00 L and the reaction 2 NO2(g) ∆N2O4(g) was allowed to come to equilibrium at 298 K. (a) Using information in Table 5E.2, calculate the equilibrium concentrations of the two gases. (b) The volume of the flask is reduced to half...

Phuong Tran 1G

Consider the equilibrium CO(g) 1 H2O(g) ∆CO2(g) 1 H2(g). (a) If the partial pressure of CO2 is increased, what happens to the partial pressure of H2? (b) If the partial pressure of CO is decreased, what happens to the partial pressure of CO2? (c) If the concentration of CO is increased, what happens...

Phuong Tran 1G

The equilibrium constant Kc 5 0.56 for the reaction PCl3(g)1 Cl2(g) ∆ PCl5(g) at 250 8C. Upon analysis, 1.50 mol PCl5, 3.00 mol PCl3, and 0.500 mol Cl2 were found to be present in a reaction vessel of volume 0.500 L at 250 8C. (a) Is the reaction at equilibrium? (b) If not, in which direction does i...

Phuong Tran 1G

Hi! For Homework problem 51.13, part c asked which is thermodynamically more stable relative to its atoms at 1000 K, Cl2 or F2. I know that F2 has a bigger equilibrium constant for dissociation of F2 o F atoms than that of Cl2 to CL atoms. This means that F2 will dissociate more. How do I know which...

Phuong Tran 1G

I’m also confused on what standard enthalpy of formation is

Phuong Tran 1G

How do we now that something is at standard reaction enthalpy. I know that it’s enthalpy at pure form but how do we know that? Do they tell us in the question?

Phuong Tran 1G

The autoprotolysis reaction is endothermic; do you expect Kw to increase or decrease with increasing temperature?

Since it’s endothermic, the reaction is absorbing heat so with increasing temperature, Kw would decrease? Is it the same idea as it is for K?

Phuong Tran 1G

Kelvin is usually the units that they ask you for. However, depending on the problem, using kelvin or Celsius would not matter if you are looking for the change between the initial and final

Phuong Tran 1G

They simply added the 1st and 2nd equations together and kept the molecules on their respective sides. 2 P(g) + 3 Cl2(g) <—-> 2 PCl3(g) + 2 PCl3(g) + 2 Cl2(g) <—-> 2 PCl5(g) = 2 P + 3 Cl2 + 2 PCl3 + 2 Cl2 <-> 2 PCl3 + 2 PCl5 and you could subtract 2 PCl3 from each side and therefore removing them, ...

Phuong Tran 1G

Hi! So I’m reviewing and 5h.2 states hat chemical equations can be expressed as sum of 2 or more chemical equations. The book gave 3 gas phase equations and did the following: 2 P(g) + 3 Cl2(g) <—-> 2 PCl3(g) 2 PCl3(g) + 2 Cl2(g) <—-> 2 PCl5(g) 2 P(g) + 5 Cl2(g) <—-> 2 PCl5(g) So they added the two ...

Phuong Tran 1G

Use Le Chatelier's principle to predict how the equilibrium composition of a reaction mixture is affected by: adding or removing reagents; compressing or expanding a gaseous mixture; and by raising or lowering the temperature.

Can someone explain the reasons for the last part?

Phuong Tran 1G

Hi! So i understand that a state function is a property that depends on the current state and not the consequent paths to get there. I don’t understand how work and heat are not state functions while internal energy is. Can someone explain that

Phuong Tran 1G

And does anyone know what day the posts reset for points? Would it be every sunday or every Monday?

Phuong Tran 1G

I missed 5 points for the chemistry community. Will there be extra points in the class?

Phuong Tran 1G

Can someone check my answers and help me explain some of these ? A) coffee in a very high quality thermos bottle would be isolated system because the bottle is conserving the heat so its trapped B) coolant in a refrig coil Don’t get what this one means C) a bomb calorimeter in which benzene is burne...

Phuong Tran 1G

So, from what Ive read on the textbook, a reversible process means any small change can cause the object working against opposing force to move in or out? Also, can someone explain what this means? Expansion against external pressure that differs by a measurable amount from the pressure of the syste...

Phuong Tran 1G

Is the answer the same for both a and b, which would be 6.8 since x= 1.45*10^-7 and [H3O]=[OH-]

Phuong Tran 1G

27. A mixture of 2.5 moles H2O and 100 g of C are placed in a 50 L container and allowed to come to equilibrium subject to the following reaction: C(s) + H2O (g) ⇌ CO (g) + H2 (g) The equilibrium concentration of hydrogen is found to be [H2] = 0.040 M. What is the equilibrium concentration of water,...

Phuong Tran 1G

47. The reaction 2 SO2 (g) + O2 (g) ⇌ 2 SO3 (g) occurs in a 1.00 L flask at 312 K and at equilibrium the concentrations are 0.075 mol.L-1 SO2 (g), 0.537 mol.L-1 O2 (g), and 0.925 mol.L-1 SO3 (g). Calculate their respective partial pressures at 312 K using R = 8.206 × 10-2 L.atm.K-1.mol-1. A. Pso2 = ...

Phuong Tran 1G

Question 18 asks that we find the equilibrium constant given an equilibrium reaction and the partial pressures (in Bars) at 500 K.

It doesn’t specify to find Kp or Kc. Do I assume that it is asking for Kp so I would not need to convert or Kc, by which means I have to convert?

Phuong Tran 1G

Hi, so I was doing 5g.11 and I got confused about gas phases. So for K, there’s Kc and Kp, and you use Kp for partial pressures for gas phases right while you use Kc for aq.

Why is it that you are solving for the concentration of the gas for Q but the partial pressure of gas for Kp?

Phuong Tran 1G

Hi! Can someone explain why c wouldn’t be the same? I know that d and e are the same in both containers because they’re the ratio of the equilibrium constant and the reverse of it, but what about C? The only explanation I thought of was that c isn’t in a balanced equation so it can’t reach equilibri...

Phuong Tran 1G

Hi! For the b part, you have to balance the equation first before you write the expression for K right?

How would you balance the eq?
4NH3 + 6NO — 7N2 + 6H20

Phuong Tran 1G

Would d be true because you are not changing the K value of the concentration at equilibrium and to achieve that k value, you would need a higher equilibrium concentration of product to keep it balanced?

Phuong Tran 1G

When you increase the concentrations of products, is the equilibrium reaction affected? I know that the value of K does not change, so can I say that the position of the reaction rate Q changes relative to K? Would that make the statement true?

Phuong Tran 1G

No, but I’ve been to a UA’s workshop (Lyndon) and he basically gives out a worksheet and go over it.

Phuong Tran 1G

If the temperature increases, would the value of K increase too?

Phuong Tran 1G

When calculating Q, you are only going in one direction because Q could be calculated regardless of whether or not the reaction is in equilibrium.

Phuong Tran 1G

So I have the 6th edition of the textbook. Do I need to buy the 7th edition because I can’t find the homework problems that he listed. If anyone else have the 6th edition, what page and problems would it be?

Phuong Tran 1G

When K is greater than a 1000, the reaction strongly favors the products. Therefore, the reaction lies to the right so there will be very little forward reaction. When K is less than 10^-3, the reaction strongly favors the reactants. Therefore, the reaction lies to the left so the reaction would b c...

Phuong Tran 1G

Q is the reaction quotient and has the same formula as K. Q would be equal to the concentrations of the product over the concentrations of the reactants. However, unlike K, Q can be used even when the equation isn’t in equilibrium. You then use Q and compare it to K to see how far the reaction is fr...

Phuong Tran 1G

What do you do when the equilibrium equation includes both aqueous and gas phases? Do you solve for each independently and somehow add them or do you convert?

CHEMISTRY COMMUNITY

Search found 33 matches

Memorizing acids and bases

5.39 HW

5J.1

5I.27

Determining what’s thermodynamically more stable

Re: Difference between standard reaction enthalpy and enthalpy

Difference between standard reaction enthalpy and enthalpy

Kw with increasing temperature in endothermic reaction

Re: Temperature

Re: 5H.2 Clarifications

5H.2 Clarifications

Explaining Le Chatelier’s principle

State functions; definition and clarifications

Re: Extra Credit

Extra Credit

4a.1

Define Reversible process

6A.21

POST ASSESSMENT PART 1B NUMBER 27

Post Assessment PART 1B NUMBER 47

Post Assessment Part 1B number 18

Including gasses for Q vs K

5G 9 HW C VS. D AND E

5g.3 b HOMEWORK

5G.1 d homework

Homework 5g.1 B

Re: Office Hours

Re: Temperature change

Re: Difference between -> and <->

6th edition and homework problems

Re: K being small or large

Re: Q versus K

Calculating K when there is multiple phases