CHEMISTRY COMMUNITY

Xinyi_Yan_3L

"This is a favored process, but with a high energy barrier."

Xinyi_Yan_3L

I also don't think so. Alcohol functional group is a hydroxyl group that attaches to a saturated carbon. However, because the OH of phenol functional group is attached to a benzene ring, the hydroxyl group of phenol attaches to an unsaturated carbon. Therefore the phenol functional group is differen...

Xinyi_Yan_3L

This can be explained with the Arrhenius equation: k=A*Exp(-EA/(R*T)), which is determined through experiments. A higher energy level means reactants must collide with higher energy, which is harder to achieve. Therefore the rate is lower and the rate constant is smaller.

Xinyi_Yan_3L

Because ozone is constantly produced in the upper atmosphere, where there is intense ultraviolet light. UV light has shortwave length and high frequency(higher energy), and can break O2 into two oxygen atoms. The single oxygen atom combines with O2 to form O3. So even though ozone tends to sink or b...

Xinyi_Yan_3L

Xinyi_Yan_3L

I think here "configuration" infers electron configuration rather than geometry orientation. Clearly F has a more complex electron configuration than H. A more complex electron configuration means more possible microstates. Therefore the more F the molecule has, the larger the molar entropy.

Xinyi_Yan_3L

Actually this process leads to an decrease in entropy. For an isothermal process, ΔG=q(reversible)/T
Clearly, since the system (the glass of water) is losing heat, q is negative Thus ΔG is also negative, which means decrease in entropy.

Xinyi_Yan_3L

For irreversible expansions, an example would be a piston with atmosphere as external environment. But can some one give me a real-life situation as an example of a reversible expansion, if there's any? I understand in reversible expansion process, the pressures of the system and exterior are always...

Xinyi_Yan_3L

You can decide which method to use by looking at what information you are given in the question. When you know the reaction enthalpies of reactions related to your given reactions, you use Hess's law. For example, if you are given N2+ O2= 2NO ΔH1°=180.5 kJ and N2+2O2=2NO2 ΔH2°=66.4 kJ, and want to ...

Xinyi_Yan_3L

Thanks so much!

Xinyi_Yan_3L

According to its Lewis structure, aqua(H2O) has two lone pairs. This means that aqua can possibly bind to two molecules, right? But why it is monodentate?

Xinyi_Yan_3L

Basically you can calculate the bond order by counting the bonds, with the help of the lewis structure. For example, O2 has a double bond and has a bond order of 2. If we draw the lewis structure for NO3-, we may find out that it's a resonance structure with one double bond and two single bonds. So ...

Xinyi_Yan_3L

Na is not an acidic cation not because of its charge, but because NaOH is a strong acid and ionizes completely in water. So yes, ClO is the only ion reacting with water and the determining the pH. And NaClO is basic and your reason is correct For AlClO3, I think we need the specific ka and kb of Al ...

Xinyi_Yan_3L

So according to the graph, Change in A=ΔA=27.5-27.5=-10 (approximately), ΔB=5, ΔC=10 ΔA: ΔB: ΔC=2:1:2, which means for every two unit's of decrease in A's PP, there is one unit of increase in C's PP and two in D's. So the coefficient of A, B, and C is 2: 1: 2 And the equation will be: 2A --> B + 2C ...

Xinyi_Yan_3L

As initially the concentration for N2 is 0 and equilibrium concentration is x, the change in N2 concentration is x. The change in NO concentration is -2x, twice the change in N2 concentration. Given NO' s initial concentration (1.0) and change in concentration (-2x), we can know that the equilibrium...

Xinyi_Yan_3L

I don't know the exact reason, but we can make generalization by comparing sp3 and sp2 orbitals. The sp2 orbitals has less p-character and more s-character than sp3 (you may think of sp2 has 1/3 s, while sp3 has 1/4 s), and has lager bond angles. Generally, the more s-character the hybrid orbital ha...

Xinyi_Yan_3L

After sulfur forms bonds with each of the fluorine, it still has a lone pair left. The side with the lone pair has a slightly negative charge, thee other side has a slightly positive charge. So SF4 is polar.

Xinyi_Yan_3L

: I saw this on Facebook. It's so funny.

Xinyi_Yan_3L

I learnt in class that 3d orbital has lower energy level than the 4s orbital. Then why electrons first fill in 4s orbitals before they go to 3d?

Xinyi_Yan_3L

To know the kinetic energy of the electrons, you need to know both their mass and velocity. According to the formula: E(k)=(1/2)m*v^2 The mass of one mole of electrons is 9.1*10^-31kg * 6.02*10^23/mol(Avogadro's number) * 1mol. And the unit of v^2 is (m/s)^2, the unit of the final answer is: kg*m^2/...

Xinyi_Yan_3L

397.0nm The next wavelength is the fifth in balmer series and is for light emitted when electron transits from n=7 to n=2 by definition. First calculate the energy difference between n=7 and n=2 using the equation: ΔE=E2-E7=-hR/4-(-hr/49)=-5.008*10^(-19)J ΔE is negative because energy is emitted as ...

CHEMISTRY COMMUNITY

Search found 21 matches

Re: Post All Chemistry Jokes Here

Re: Determining phenol functional groups

Re: Ratio of Rate Constants (Energy Barriers)

Re: Gases in Atmosphere

Re: Post All Chemistry Jokes Here

Re: Practice Midterm Winter 2013: Q5B

Re: Quiz question #7

Example of reversible expansion?

Re: Using Reaction Enthalpies

Re: Why aqua is monodentate?

Why aqua is monodentate?

Re: Calculating Bond Order

Re: classifying acidity/basicity of NaClO

Re: Chapter 11 Q 89

Re: Chapter 11 Question 43

Re: Homework 4.43

Re: 25.d

Re: Post All Chemistry Jokes Here

3d and 4s orbitals

Re: Kinetic Energy of Electrons to moles? [ENDORSED]

Re: 1.57 : Wavelength of next line in series ?