CHEMISTRY COMMUNITY

Jessica_Singh_1J

Leah Savage 2F wrote:Are ketones only made up of C bound to O and two C groups? Could it be bound to a C group and something other than H?

No, because then it would be an aldehyde. Aldehydes end the carbon chains and while ketones are located in the middle.

Jessica_Singh_1J

Basically, heterocyclic amines are produced when protein-rich meats like beef, fish, and poultry are cooked at high temperatures (basically well-done meat). They're carcinogenic in that they produce DNA adducts (segments of DNA bound to a cancer-causing chemical) through the formation of N-C bonds a...

Jessica_Singh_1J

We'll probably only be expected to know what was covered in class, i.e. identifying the different functional groups based on given structures.

Jessica_Singh_1J

Half lives can be very useful in determining the approximate age of organic objects via radiometric dating.

Jessica_Singh_1J

The catalytic converter in a car contains platinum, which serves as a catalyst to change carbon monoxide, which is toxic, into carbon dioxide.

Jessica_Singh_1J

As a reminder:

the units for k in a 0 order reaction are: mol/L*s , for a 1st order reaction are: 1/s, for a 2nd order reaction are: L/mol*s.

Jessica_Singh_1J

In regards to applications, half lives can be very useful in determining the approximate age of organic objects via radiometric dating!

Jessica_Singh_1J

The rate of reaction is dependent upon the amount of activation energy the reaction requires. A high activation energy means a slower rate of reaction, and vice versa. Catalysts work to increase the rate of reaction by lowering activation energy.

Jessica_Singh_1J

Q is the quotient calculated at non equilibrium conditions while K is the quotient calculated at equilibrium.

Jessica_Singh_1J

A galvanic cell is simply a type of electrochemical cell.

Jessica_Singh_1J

Galvanic cells are also known as voltaic cells; they are electrochemical cells that in which a spontaneous chemical reaction is used to generate an electric current.

Jessica_Singh_1J

Oxidizing agents cause other species to be oxidized by accepting their electrons, themselves being reduced in the reaction.
Reducing agents cause other species to be reduced by donating their electrons, themselves being oxidized in the reaction.

Jessica_Singh_1J

The question usually specifies whether the conditions are acidic or basic if that information is pertinent to the solution.

Jessica_Singh_1J

The value of ΔG changes as a reaction proceeds but the value of ΔG° is a fixed quantity throughout the reaction.

Jessica_Singh_1J

Additionally, the value of ΔG changes as a reaction proceeds while ΔG° is a fixed quantity throughout the reaction.

Jessica_Singh_1J

Microstates are the number of possible positions and motions a molecule can take on in a given system. As entropy increases, so does the number of positions and motions available to the molecule. For example, in the case of the expansion of a gas, given more space, the molecules of the gas are less ...

Jessica_Singh_1J

A negative deltaG is favored because then the reaction will proceed spontaneously and exothermically, releasing heat and increasing the entropy of its surroundings. Reactions that increase entropy are usually more favorable than reactions that require energy and do the opposite.

Jessica_Singh_1J

Beza, generally I would say yes because "favorable" reactions refer to spontaneous exergonic reactions which tend to occur without an input of energy.

Jessica_Singh_1J

Another way to think about entropy is to consider the number of possible positions and motions (microstates) a molecule can take on in a given system. As entropy increases, so does the number of positions and motions available to the molecule. For example: in the expansion of a gas, the molecules of...

Jessica_Singh_1J

DeltaG is a measure of the change in free energy of a reaction, whereas deltaS is a measure of the change in entropy. The equation deltaG = deltaH - TdeltaS uses the changes in enthalpy (deltaH) and entropy (deltaS) at constant temperature to calculate change in free energy (deltaG). A negative delt...

Jessica_Singh_1J

When the slope is negative, G is negative, indicating an exergonic reaction (releases energy - spontaneous). When the slope is positive, G is positive, indicating an endergonic reaction (requires energy).

Jessica_Singh_1J

Also, in combustion, it's almost always the vapor burning- not the liquid.

Jessica_Singh_1J

Yup- adiabatic systems have 0 heat transfer and isolated systems have 0 energy transfer at all.

Jessica_Singh_1J

Of course, this also depends on the type of system. For instance, isolated systems cannot exchange energy or matter with their surroundings.

Jessica_Singh_1J

Nope - an isolated system can exchange neither matter nor energy with its surroundings.

Jessica_Singh_1J

It's also important to note that a system with adiabatic walls is not necessarily a closed system- energy can be transferred as work!

Jessica_Singh_1J

Work is positive because it is being done ON the system (energy is added), whereas if the pump expanded (energy is expended) work would be negative because it is being done BY the system.

Jessica_Singh_1J

I agree with Sophia. I think of thermal energy as the total internal energy while heat is the form of energy that flows between two objects due to a temperature difference.

Jessica_Singh_1J

Some examples of extensive properties include length, weight, size, mass, and volume. Some intensive properties include boiling/melting point, density, odor, color, ductility, and malleability.

Jessica_Singh_1J

It's important to note that a system with adiabatic walls is not necessarily an isolated system; energy can be transferred to or from the system as work.

Jessica_Singh_1J

Definitely make sure to ask your instructors which notation they prefer beforehand.

Jessica_Singh_1J

Chlorine does. One would expect it to be fluorine, but fluorine is a pretty small atom with a very small amount of space in its 2p orbital.

Jessica_Singh_1J

I'm not quite sure, but knowing the full formulas does help in determining the denticity of these ligands, which is essential.

Jessica_Singh_1J

Diamagnetism indicates that all electrons are paired; such molecules tend to move out of a magnetic field.
Paramagnetism refers to molecules that possess unpaired electrons; such species tend to move into a magnetic field.

Jessica_Singh_1J

Yes, the conjugate base produced is basic.

Jessica_Singh_1J

Yes, you would attach the C to the central atom.

Jessica_Singh_1J

When naming a compound, you can definitely just use (en) or (dien) or whatever the shorthand may be; however you should probably also know the whole name just in case.

Jessica_Singh_1J

Organic coordination compounds probably have the most relevance to biological structures.

Jessica_Singh_1J

Paramagnetism refers to molecules that possess unpaired electrons; such species tend to move into a magnetic field.

Jessica_Singh_1J

Another (organic) approach to this problem is to recognize that HOCO is simply a rearrangement of -COOH, the general formula of a carboxylic acid (an organic functional group). Knowing that organic molecules are chains or rings of C, we can conclude that the radical is placed on the carbon atom.

Jessica_Singh_1J

Organic molecules are usually found in living systems; they always consist of carbon in the form of chains or rings. Organic molecules will usually consist of C, H, O, or N. Inorganic molecules don't really consist of C and are not normally found in living things.

Jessica_Singh_1J

These terms don't directly refer to the orientation of dipoles around the molecule. Cis- and trans- are used to describe geometric isomerism (isomers are molecules with the same molecular formula but different arrangements of individual atoms in space). If two groups are located on the same side of ...

Jessica_Singh_1J

Once you determine the Lewis structure of the molecule, all you have to do is determine the amount of single, double, and triple bonds. Remember: a single bond consists of 1 sigma bond; a double bond consists of 1 sigma bond and 1 pi bond; a triple bond consists of 1 sigma bond and 2 pi bonds. CO2 h...

Jessica_Singh_1J

In benzene, each carbon atom contributes one unhybridized 2p electron, giving us a total of 6 unhybridized 2p electrons. These 2p electrons bond together to form pi bonds; thus (6 2p electrons)/(2 electrons per bond) = 3 pi bonds. These 3 pi bonds are the double bonds involved in benzene's structure.

Jessica_Singh_1J

Yes, given that electropositivity is the opposite of electronegativity, it can be defined as the ability of an element to lose electrons and form positive ions (cations).

Jessica_Singh_1J

Ionization energy is the energy required to remove an electron from an atom in the gaseous state. Because noble gases have a full octet, their ionization energies are actually quite high. Electron affinity is the amount of energy released when an electron is added to a neutral atom. Because noble ga...

Jessica_Singh_1J

Larger anions have a higher polarizability due to their larger size, which allows for electrons to be held more loosely. This in turn allows for them to be more easily distorted by smaller cations.

Jessica_Singh_1J

Smaller cations have a higher polarizing power due to their greater concentrations of positive charge; likewise larger anions have a higher polarizability due to the fact that they have a larger size so electrons are then more loosely held.

Jessica_Singh_1J

Bohr assumed that when an electron is removed completely, the energy of the system is 0. However, when the electron is still around the nucleus, the system is more stable and thus at a lower energy. Thus, there is a negative sign in front of the equation.

Jessica_Singh_1J

All radii generally follow the same trend on the periodic table.

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