CHEMISTRY COMMUNITY

Kira_Maszewski_1B

For something with multiple phase changes and temperature changes, we use both the q=m*C*delta_T formula and the q=n*delta_H formulas. For example: If we we have a change in temperature of water from -5 degrees centigrade to 125 degrees centigrade, then we will need to use the q=m*C*delta_T for the ...

Kira_Maszewski_1B

When are we supposed to use the pre equilibrium approach? If there is an intermediate in the first step and the first step is also the slow step, would we need to use the pre-equilibrium approach to find the rate law and get rid of the intermediate?

Kira_Maszewski_1B

In a two step reaction, if there is a initial reactant that shows up as a final product, is it a catalyst? Meaning the reactant was unchanged and unaffected?

Kira_Maszewski_1B

You would use dashes to separate the position of the substituents or functional group from the type of substituent or functional group. Also, we use them to separate the position of a double bond or triple bond. For Example: 3,2-dimethylbutane 2-ethylpent-1-ene --------> 1 represents the carbon that...

Kira_Maszewski_1B

When ethene is bubbled through bromine water, the solution is decolorized. Which of the following is true regarding the reaction? 1. Br2 acts as a nucleophile 2. Br2 attacks the carbons of the double bond in one step. 3. The first step is the removal of a hydrogen atom to form [C2H3]- 4. The Br- ion...

Kira_Maszewski_1B

When will the quiz 3 preparation answers be posted?

Kira_Maszewski_1B

What type of reactant is cyanide? Draw its Lewis structure and comment on how it can react. What is the hybridization of the carbon and nitrogen atoms?
I found this question in the OChem textbook. Please explain how to solve this.

Kira_Maszewski_1B

It is important to distinguish between the reaction and the rate constant. The units of rate constant are always M * s^-1. True or False.

I think the answer is True, however I'm not sure about this question. Could someone please explain?

Kira_Maszewski_1B

The standard reaction free energy for H2(g)+I2(g) <-->2HI(g) is DeltaG = -21.1 kj at 500K. In a sealed reaction container, the equilibrium partial pressures of the gases are PH2= 1.2 bar, PI2 = 1.5 bar, and PHI is unknown. a) Calculate the value of the equilibrium constant for this reaction. b) Calc...

Kira_Maszewski_1B

Can someone verify that the equation needed to solve #12 is the one we learned for calculating standard free energy change? I am getting caught up in the wording: "Calculate the standard Gibbs free energy". Should I be using a different equation (even though we're given standard change in...

Kira_Maszewski_1B

Can someone please explain how I should approach #11? You divide 49.7 by the molar mass of PbO to get the number of moles, then multiply that by the deltaH to get the heat released by the reaction of that amount of PbO. You then use q=mCdeltaT and solve for m. 49.7g/(223.2g/mol)=0.223mol; 0.223mol*...

Kira_Maszewski_1B

I am also wondering about #9, specifically about ΔS(surr), why is it not 0? Isn't it a state function, too? Please read carefully: Changes in state functions of the system are zero when the system returns to the same initial conditions. Delta S (total) > 0 for this process. Therefore delta S (surro...

Kira_Maszewski_1B

What equation do we use for work in #3?

Kira_Maszewski_1B

Hi, After getting the enthalpy of the reaction to be -169.2 kJ, it should be easier to understand if you write out the whole process. The enthalpy of the reaction should equal the enthalpy of the products minus the reactants of the equation 2NO + 3/2O2 --> N2O5. Thus, you get -169.2 kJ = deltaHfN2O...

Kira_Maszewski_1B

Can someone explain why -169.2 kJ (the enthalpy of the reaction 2NO + 3/2 O2 ---> N2O5) equals the enthalpy of formation of N2O5 minus twice the enthalpy of formation of NO?

Kira_Maszewski_1B

What is the equation that is being used to solve for the reaction enthalpy in this problem?

Kira_Maszewski_1B

How do we calculate for the answer of Self-Test 8.1A in the the Chemical Principles 6e textbook? It is the example about finding the work that water does when it freezes and pushes back the metal wall of a pipe...

CHEMISTRY COMMUNITY

Search found 17 matches

Re: General formula for phase changes for enthalpy.

Pre- equilibrium approach [ENDORSED]

Re: Catalyst

Re: Naming [ENDORSED]

Solution is "decolorized" (Quiz 3 Prep)

Quiz 3 Prep answers

Naming type of reactant and commenting on reaction.

Re: Quiz 2 Winter 2017. Help on Quiz 2 Prep please!

Calculating Equilibrium constant

Re: Quiz 1 Preparation Answers

Re: Quiz 1 Preparation Answers

Re: Quiz 1 Preparation Answers

Re: Quiz 1 Preparation Answers

Re: Chapter 8 Question 65

Chapter 8 Question 65

Re: Chapter 8 #59 [ENDORSED]

Calculating the work done when water freezes and expands