Basic Mole Concept Questions, Grade 11 Chem

In summary, the conversation covers topics in chemistry including the mole concept, a question about the number of chlorine molecules present in a reaction with nitrogen, and the relation between the mole and grams. The formula for the compound formed in the reaction is suggested to be NCl3, also known as nitrogen trichloride. The conversation also briefly touches on the history of how the atomic mass unit was determined.
  • #1
Senjai
104
0
Hey guys, I'm back, finished my term in physics with a 96% final grade, thanks to all you guys.

So i thought id try you guys before i went to find a chemistry help forum.

I get the Mole Concept, kinda, here's an example question (i got an answer, not sure if its right, we don't get a "back of the book" for chemistry. But its a great question to base my issues upon.

If 1.0L of nitrogen gas reacts with 3.0 L of chlorine gas when both gases are at the same room temperature and pressure, how many chlorine molecules are present for every molecule of nitrogen in the reaction? Suggest a formula for the compound formed and name the compound.

Alright, first of all, the mole concept illustrates that in a reaction, the amount of particles will always remain the same, or something close to that (ending spring break, trying to remember everything.) so i assumed their would me 3 molecules of chlorine, for every molecule of nitrogen, if it reacted with no leftovers, which I'm assuming.. would that be correct?

So that was my answer, suggest formula was: [tex]ClN_3[/tex] Chlorine trinitride?? is that correct? and does it matter, if it was the otherway around, trinitrogen monochloride?

Another question on the mole concept,. is how does it relate to grams? the atomic mass unit, for example 69.7u, refers to the unique mass in relation to hydrogen right? As it is 69.7 times heavier than H, (btw, I am using Gallium for this example) that would also mean its 69.7grams/1mol Ga, how does it even relate to grams, grams is such a large unit for an amount of substance for an element. Does anyone have any further reading on the mole concept that would be good for a gr 11 high school student.
 
Physics news on Phys.org
  • #2
I would think the formula name is trinitrogen monochloride since the chlorine atom has the lower oxidation state.

As for the mole concept: 1 mole is equal to 6.02 x 10^23 particles (either atoms or molecules depending on what you're working with), which means that for Ga, the combined weight of 6.02 x 10^23 atoms is equal to 69.7 grams. So how much does a single Ga atom weigh? 1 / (6.02 x 10^23 / 69.7 g ) = 1.158 x 10^-22 g, or in other words, 69.7 atomic mass units. From this, you can calculate the weight of one atomic mass unit to be 1.66 x 10^-24 g.
 
Last edited:
  • #3
ahh that would make sense, so someone just measured how many particles of hydrogen is in one gram of hydrogen, and made the amount of particles, 1 mol, and based the rest of the periodic table off of that?

I'm not sure we've learned about oxidation states yet, ill refer that to my teacher, thanks Snazzy!
 
  • #4
and i was right abuot the number of chlorine particles to nitrogen particles?
 
  • #5
Actually, someone used carbon-12 in its unbound and ground state to measure how many atoms there were in exactly 12 grams of carbon and everything was relative to that.
 
  • #6
wow that's really interesting, i greatly appreciate all the help.

EDIT: i thought someone measured the mass of hydrogen, because it was the lightest element, and declared that a value of 1.0, and measured the rest of the periodic tables elements atomic mass units in relation to how much heavier it was than hydrogen??
 
  • #7
Senjai said:
If 1.0L of nitrogen gas reacts with 3.0 L of chlorine gas when both gases are at the same room temperature and pressure, how many chlorine molecules are present for every molecule of nitrogen in the reaction? Suggest a formula for the compound formed and name the compound.

so i assumed their would me 3 molecules of chlorine, for every molecule of nitrogen, if it reacted with no leftovers, which I'm assuming.. would that be correct?

Yes.

So that was my answer, suggest formula was: [tex]ClN_3[/tex]

? Perhaps NCl3---nitrogen trichloride?
 

1. What is the definition of mole in chemistry?

The mole is a unit of measurement used in chemistry to measure the amount of a substance. It is defined as the amount of a substance that contains the same number of particles (atoms, molecules, or ions) as there are in 12 grams of carbon-12.

2. How is the Avogadro's number related to the mole concept?

The Avogadro's number (6.02 x 10^23) is the number of particles in one mole of a substance. This means that for every mole of a substance, there are 6.02 x 10^23 particles present.

3. What is the difference between molar mass and molecular mass?

Molar mass is the mass of one mole of a substance, expressed in grams per mole. It is calculated by adding up the atomic masses of all the atoms in a molecule. Molecular mass, on the other hand, is the mass of a single molecule, expressed in atomic mass units (amu).

4. How do you convert between moles and grams?

To convert from moles to grams, you can use the formula: m = n x M, where m is the mass in grams, n is the number of moles, and M is the molar mass. To convert from grams to moles, you can use the formula: n = m/M, where n is the number of moles, m is the mass in grams, and M is the molar mass.

5. How is the mole concept used in stoichiometry?

The mole concept is used in stoichiometry to calculate the amount of reactants needed and the amount of products formed in a chemical reaction. This is done by using mole ratios, which are based on the coefficients in a balanced chemical equation.

Similar threads

Replies
6
Views
2K
  • Biology and Chemistry Homework Help
Replies
2
Views
2K
  • Biology and Chemistry Homework Help
Replies
2
Views
3K
  • Introductory Physics Homework Help
Replies
3
Views
3K
  • Biology and Chemistry Homework Help
Replies
5
Views
5K
Replies
7
Views
3K
Replies
8
Views
4K
  • Biology and Chemistry Homework Help
Replies
2
Views
7K
  • Biology and Chemistry Homework Help
Replies
3
Views
2K
Replies
5
Views
3K
Back
Top