ALEKS - Writing a Chemical Equation from a Description of the Reaction
Жүктеу.....
Пікірлер: 7
@anyichibuogwu90864 жыл бұрын
So how do you know the numbers to put as the subscript when making the formula? I can never really tell, and when I ask for an explanation it just tells me that it’s 2 or 3 but it doesn’t explain where they get that number from
@TonyStJohn
4 жыл бұрын
To figure that out you really need to look at a few different things. The chemical formulas we see in this problem (and a lot of them in general) are all neutrally charged - meaning that the total overall charge of each chemical formula is (0). So, if there are (+) and (-) ions present in the chemical formula, those need to balance each other out. Looking at ZnCl2 - we know that when Zn forms ions, it ALWAYS forms (+2) ions, and Cl will form (-1) ions. Therefore to balance things out, we need 1 Zn for every 2 Cl's. Now, if you want to start talking about WHY Zn always forms a (+2) ion, or Cl always forms a (-1) ion, we need to talk about electron configurations and stability! The easiest way to understand this is to think about the noble gases. What makes them noble? Why are they so unreactive? Well, they have completely full valence shells - this causes them to be very stable and they do not want to participate in electron transfer (they are happy will full shells). Now, when an element like Cl accepts an electron, that extra electron gives Cl a (-1) charge AND fills up the valence shell - leading to greater stability. This can explain the behavior of groups 1, 2, 6 and 7 very easily - group 1 always forms (+1), group 2 always forms (+2), group 6 always forms (-2), and group 7 always forms (-1). Zn is a bit more involved of an explanation, since it's a transition metal, but the same principle applies, losing 2 electrons leaves a completely full d-shell. Hope that helps!
@anyichibuogwu9086
4 жыл бұрын
Tony St. John yea it does thank you so much!!
@angelrodriguez19295 жыл бұрын
why does Hydrogen have a 2 ?
@painx8035
4 жыл бұрын
because hydrogen is diatomic molecule
@angelrodriguez1929
4 жыл бұрын
Yeah I figured that out like 2 minutes after posting this
Пікірлер: 7
So how do you know the numbers to put as the subscript when making the formula? I can never really tell, and when I ask for an explanation it just tells me that it’s 2 or 3 but it doesn’t explain where they get that number from
@TonyStJohn
4 жыл бұрын
To figure that out you really need to look at a few different things. The chemical formulas we see in this problem (and a lot of them in general) are all neutrally charged - meaning that the total overall charge of each chemical formula is (0). So, if there are (+) and (-) ions present in the chemical formula, those need to balance each other out. Looking at ZnCl2 - we know that when Zn forms ions, it ALWAYS forms (+2) ions, and Cl will form (-1) ions. Therefore to balance things out, we need 1 Zn for every 2 Cl's. Now, if you want to start talking about WHY Zn always forms a (+2) ion, or Cl always forms a (-1) ion, we need to talk about electron configurations and stability! The easiest way to understand this is to think about the noble gases. What makes them noble? Why are they so unreactive? Well, they have completely full valence shells - this causes them to be very stable and they do not want to participate in electron transfer (they are happy will full shells). Now, when an element like Cl accepts an electron, that extra electron gives Cl a (-1) charge AND fills up the valence shell - leading to greater stability. This can explain the behavior of groups 1, 2, 6 and 7 very easily - group 1 always forms (+1), group 2 always forms (+2), group 6 always forms (-2), and group 7 always forms (-1). Zn is a bit more involved of an explanation, since it's a transition metal, but the same principle applies, losing 2 electrons leaves a completely full d-shell. Hope that helps!
@anyichibuogwu9086
4 жыл бұрын
Tony St. John yea it does thank you so much!!
why does Hydrogen have a 2 ?
@painx8035
4 жыл бұрын
because hydrogen is diatomic molecule
@angelrodriguez1929
4 жыл бұрын
Yeah I figured that out like 2 minutes after posting this
@angelrodriguez1929
4 жыл бұрын
But thanks