13 replies to this topic

[Kung-Fu Barbie]

Unlike the other games, which are rather mindless, this game will test your knowledge of chemistry.
I'm going to start the chemistry game off easy and I hope you help me in letting it progress gradually to more complex questions in the future. What I'd love to happen is for this thread to touch on a ton of historical and theoretical facts that form a web that paints a coherent picture that someone who knows nothing about chemistry can learn a lot from, and also be something that someone who knows a lot about chemistry can appreciate.

I'll ask the first question, and then whoever answers it will then have the next question. Make sure your questions aren't to advanced until further in the game. Just try to eyeball it, and it's best to err on the easy side.

What is the difference between an element (as in, what makes each element unique?), an isotope, and an ion?

[Mathieu]

Arighty....

The differences between the elements are that each of them has a different number of protons.... changing the number of protons changes the element.  To describe an isotope let's just pick a random element like carbon.... carbon has 6 protons and for the most part 6 neutrons as well.... an isotope of carbon will still have 6 protons (or it wouldn't be carbon), but the number of neutrons would be different.  It may have 7 neutrons or some other number, although 6 or 7 neutrons is the most common.  An ion is an element with charge.  For example, putting salt into water and dissolving it creates sodium and chloride ions, sodium having a positive charge and chlorine having a negative charge because their electron valence shells are no longer filled because the sodium and chlorine are no longer bonded to each other when in water. I guess that's the complicated example, but an ion is just really an atom with a number of electrons different than the number of protons in the element.

[Kyle]

so what's your question Mathieu?

[Mathieu]

What are Valence electrons and what can they be used for?  And is there a pattern of how many valence electrons an atom has as you move across the periodic table?

[Godless-Liberal]

Valence electrons are the ones in the outermost rings.  As you move from left to right on the periodic table, the number increases.  These electrons control how reactive the elements are with one another, and it is an inverse relationship.  


What is the difference between heterogeneous and homogeneous mixtures?

[Prince Manny]

The prefixes "homo"- indicate sameness.
The prefixes: "hetero"- indicate difference.
A homogeneous mixture has the same uniform appearance and composition throughout. Many homogeneous mixtures are commonly referred to as solutions.
A heterogeneous mixture consists of visibly different substances or phases. The three phases or states of matter are gas, liquid, and solid.
An example of a Homogeneous mixture is brewed coffee.
An example of a Heterogeneous mixture is orange juice with pulp in it or a carbonated beverage (the CO2 gas is mixed with the liquid).

[Prince Manny]

My Question :


N2 + 3H2 ---> 2NH3

If 55.0g of nitrogen gas is placed in a reaction container with 55.0g of hydrogen gas, determine which chemical is the limiting reactant and the number of g. of ammonia gas that can be produced by this reaction.

[Beka]

1. the molecular weight of N2 is 14 X 2 = 28.0 g
b. you have 55.0 g of N2
c. therefore you have 55.0 g divided by 28.0 g/mol = 1.96 mol N2

2. the molecular weight of H2 gas is 2 g
b. therefore you have 27.5 mol of H2

The limiting reagent is N2 gas

3. The stoichiometry of the reaction is 1N2 : 3 H2 --> 2 NH3

you have 1.96 mol of the limiting reagent N2 (instead of the ration of 1 as above) - therefore multiply all molar quatities by 1.96 and you end up with 1.96 X 2 moles of NH3 which is 3.92 moles of NH3

The molecular weight of NH3 is 14 + 3(1) = 17.0 g
3.92 mol X 17 g/mol = 66.6 g of NH3 produced.







My Question :

What is the theory behind the ideal gas equation?

[Sammilicious]

I have no concept of chemistry that's more Kyle and Manny's thing

[Dionysus]

nope this game is not for me

[faithrose]

ask me later when I am not so tired lol

[Kaliratra]

Ideal Gas Law states that pv=nrt, meaning that pressure X volume= particulate number (number of atoms or molecules particular to an element or molecular construct) X constant(because we all love constants) X temperature (between two thresholds to the liquid and plasma state).  This law is a combination of multiple, prior laws and observations regarding gaseous behaviors, such as Boyle's Law.  The theory behind ideal gas law is that certain variables are directly proportional while others are inversely proportional.

Next question:
What makes an organic molecule organic?

[Stupendous Man]

The difference between organic and inorganic molecules is carbon. Carbon is the key to organic molecules.


Next Question :

Which of the following produces an INCREASE in entropy of the system?

   1. H2O(l) --> H2O(s)
   2. 2O2(g) + 2SO(g) --> 2SO3(g)
   3. 2CH3OH(g) + 3O2(g) --> 2CO2(g) + 4H2O(l)
   4. I2(s) --> I2(l)
   5. None of the above.

[The_NuttyTart]

is it number one????...mixing water and ice????