[redXI]

1.Decomposition of phosporus pentachloride to produce phosporus trichloride and chlorine gas, my teacher said that the asnwer is:
PCl5 -> PCl3 + Cl2

BUT, I disagree and debated with him, since u need to balance it in the first place, like the PCl5 should be P5(Cl5)3. Am I right??

2. Hydrogen peroxide, H2O2, decomposes rapidly to give gaseous oxygen and liquid water. So, the answer should be:

H2O2 -> O2 + H2 , right? My friend told me that the correct one is:

H2O2 -> O2 + H2O , surely this one is wrong because it's not even balanced. But, my conscience says that mine is wrong.

3. I just received a new homework again,
"Make drawings showing the decomposition of six molecules of ammonia gas to form hydrogen and nitrogen"
So, I need to draw SIX Ammonia gas at once?? If that's so, then I'll have to draw 6 ammonia, 6 Nitrogen and 18 Hydrogen?? That's insane.

I need your guys' help for these troublesome questions. Thanks.  :1eye:

[jubba]

1.Decomposition of phosporus pentachloride to produce phosporus trichloride and chlorine gas, my teacher said that the asnwer is:
PCl5 -> PCl3 + Cl2

BUT, I disagree and debated with him, since u need to balance it in the first place, like the PCl5 should be P5(Cl5)3. Am I right??

2. Hydrogen peroxide, H2O2, decomposes rapidly to give gaseous oxygen and liquid water. So, the answer should be:

H2O2 -> O2 + H2 , right? My friend told me that the correct one is:

H2O2 -> O2 + H2O , surely this one is wrong because it's not even balanced. But, my conscience says that mine is wrong.

3. I just received a new homework again,
"Make drawings showing the decomposition of six molecules of ammonia gas to form hydrogen and nitrogen"
So, I need to draw SIX Ammonia gas at once?? If that's so, then I'll have to draw 6 ammonia, 6 Nitrogen and 18 Hydrogen?? That's insane.

I need your guys' help for these troublesome questions. Thanks.  :1eye:

1.PCl5 -> PCl3 + Cl2 is correct it is balanced. The amount of phosphorous and chlorine atoms on both sides is equal

2. H2O2 -> O2 + H2O
the balanced equation is
2H202 --->02  + 2H2O

3. I would asume you can draw one and then write *6 after it. And do the same for the hydrogen and nitrogen. But remember it nitrogen gas(N2) and hydrogen gas(H2).

[Borek]

1.Decomposition of phosporus pentachloride to produce phosporus trichloride and chlorine gas, my teacher said that the asnwer is:
PCl5 -> PCl3 + Cl2

BUT, I disagree and debated with him, since u need to balance it in the first place, like the PCl5 should be P5(Cl5)3. Am I right??

No. PCl5 it is. Why do you think it should be something else?

2. Hydrogen peroxide, H2O2, decomposes rapidly to give gaseous oxygen and liquid water. So, the answer should be:

H2O2 -> O2 + H2 , right?

No. As you have stated: decomposes to oxygen and water, not oxygen and hydrogen.

My friend told me that the correct one is:

H2O2 -> O2 + H2O , surely this one is wrong because it's not even balanced.

It is not balanced, but it contains correct substrates and products. It is up to you to balance it now.

"Make drawings showing the decomposition of six molecules of ammonia gas to form hydrogen and nitrogen"
So, I need to draw SIX Ammonia gas at once?? If that's so, then I'll have to draw 6 ammonia, 6 Nitrogen and 18 Hydrogen?? That's insane.

No idea why six molecules, however, no 6 nitrogen atoms and 18 hydrogen atoms - both are diatomic gaes.

[redXI]

P5(Cl5)3! Because the valency for
P = 3
Cl5 = 5
Right?

[Borek]

Cl5 = 5

It should be just Cl.

[Mitch]

P5(Cl5)3! Because the valency for
P = 3
Cl5 = 5
Right?

P breaks the octet rule, so it doesn't have to obey your preconceived notions on what its valency should be.

[redXI]

Is it only P that breaks the octet rule? Or perhaps, when it comes to decomposition every element breaks the rule?