Good G'Chem Question

[dat_student]

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Balance the following rxn (show your steps):

KMnO4 + NH3 -> KNO3 + MnO2 + KOH + H2O

I know, I know,...It's an easy question but try to see if you can balance this rxn in 54 seconds (100 sci. questions, 90 minutes: 54 seconds per question).

 

[mochafreak]

Balance the following rxn (show your steps):

KMnO4 + NH3 -> KNO3 + MnO2 + KOH + H2O

I know, I know,...It's an easy question but try to see if you can balance this rxn in 54 seconds (100 sci. questions, 90 minutes: 54 seconds per question).

Before everyone freaks out...there are PLENTY of easy questions on the DAT so you have more than 54 seconds for a question like this. 😉 Of course, you only have 38 seconds in DAT Achiever by the time you get to this question. 🙂 It's either dat achiever or top score, right dat_student?

 

[dat_student]

...It's either dat achiever or top score, right dat_student?

wrong...

 

[dat_student]

ok, let's do this: Can anyone balance that rxn in 540 seconds (i.e. 9 minutes)?

mocha: see my other post right above this post

 

[mochafreak]

ok, let's do this: Can anyone balance that rxn in 540 seconds (i.e. 9 minutes)?

mocha: see my other post right above this post

I did see the other post...I read them from top to bottom.

 

[Flipper405]

I tried for about 5 minutes and gave up. I'm just resigned to failure.

 

[dat_student]

Thanks mocha. 😉 Plz, see my other post right below this post. 😉

 

[dat_student]

How about 5400 seconds (i.e. 90 minutes (i.e. 1 hour 30 minutes))? Anyone?

 

[Richnator]

Balance the following rxn (show your steps):

KMnO4 + NH3 -> KNO3 + MnO2 + KOH + H2O

I know, I know,...It's an easy question but try to see if you can balance this rxn in 54 seconds (100 sci. questions, 90 minutes: 54 seconds per question).

I think if it is under acidic environment, it would be:
2KMnO4 + NH3 + 2H+ + 2e- =========> KNO3 + MnO2 + KOH + 2H20

 

[Richnator]

Oh yah, you add H20 to balance the oxygen. H+ to balance the hydrogens and e- to balance the charges on both sides. If I am not wrong that is 🙂

 

[dat_student]

I think if it is under acidic environment, it would be:
2KMnO4 + NH3 + 2H+ + 2e- =========> KNO3 + MnO2 + KOH + 2H20

You should never end up having electrons in your balanced rxn. 😉

 

[joonkimdds]

You should never end up having electrons in your balanced rxn. 😉

U still didn't provide the answer for "Funny Math Question" so i bet this is also one of those question that has no answer, or doesn't even require a thought of more than 2 sec to get the answer, right?

 

[Flipper405]

You should never end up having electrons in your balanced rxn. 😉

What about nuclear reactions with beta particles? I thought those have to have electrons in them.

 

[Richnator]

You should never end up having electrons in your balanced rxn. 😉

Ahh, yah. I realized my mistake. Forgot to perform the most crucial part. Split the reaction into the oxidation and reduction components.

 

[dat_student]

What about nuclear reactions with beta particles? I thought those have to have electrons in them.

not necessarily, gamma-decay, positron decay, alpha decay ddon't have electrons in them.

 

[Flipper405]

not necessarily, gamma-decay, positron decay, alpha decay ddon't have electrons in them.

Ok, so some don't, but some do?

 

[joonkimdds]

Ok, so some don't, but some do?

Flipper~ remember how dat_student made us to think of FUNNY QUESTION and never gave us the answer? this is the exact same thing~

 

[Flipper405]

Flipper~ remember how dat_student made us to think of FUNNY QUESTION and never gave us the answer? this is the exact same thing~

I just bumped that thread up again. 🙂 But yes, that's what I'm expecting. Maybe it'll just encourage me to figure it out for myself.

 

[joonkimdds]

I just bumped that thread up again. 🙂 But yes, that's what I'm expecting. Maybe it'll just encourage me to figure it out for myself.

I thought u gave up on that Funny Question even before I did. 🙂

how about I make a new funny question like....
if u fart under the water...what chemical reaction happens?
answer = H2O + fart oxygen = H2OOOOOOOOO....depends on how long u fart 🙂

 

[Flipper405]

I thought u gave up on that Funny Question even before I did. 🙂

how about I make a new funny question like....
if u fart under the water...what chemical reaction happens?
answer = H2O + fart oxygen = H2OOOOOOOOO....depends on how long u fart 🙂

😱

I wouldn't go telling everyone that.

 

[Richnator]

You should never end up having electrons in your balanced rxn. 😉

Ok, I split the reaction into its oxidation and reduction components.
Reduction:
MnO4- + 4H+ + 3e- ===> MnO2 + 2H20

Oxidation:

NH3+ 3H20 ===> NO3- + 9H+ + 8e-

I eliminated the K+ cation because it is a specator ion. I then used the least common mutliple of both 3 and 8, which is 24. Therefore, I multiplied the reduction part by 8 and the oxidation part by 3.

Reduction:
8MnO4- + 32H+ + 24e- ===> 8MnO2 + 16H20

Oxidation:
3NH3+ 9H20 ===> 3NO3- + 27H+ + 24e-

Adding the two reduction and oxidation parts together, I cancel out the electrions and get:

In Acidic environment:
8MnO4- + 32H+ + 3NH3 + 9H20 ===> 8MnO2 + 16H20 + 3NO3- + 27H+

Since the top equation had OH-: I must add 32 OH- to both sides to cancel out the H+

Balanced Reaction:
8MnO4- + 3NH3 + 14H20 ====> 8MnO2 +16H20 + 3NO3- + 5OH-

 

[Richnator]

Balance the following rxn (show your steps):

KMnO4 + NH3 -> KNO3 + MnO2 + KOH + H2O

I know, I know,...It's an easy question but try to see if you can balance this rxn in 54 seconds (100 sci. questions, 90 minutes: 54 seconds per question).

I can believe I typed this whole entry up and it didnt post it. Anyway, to make it short.
This is the balanced rxn.

8MnO4- + 3NH3 +14H20 ====> 8MnO2 + 16H20 + 3NO3- + 5OH-

I initially did it as if it was a acid. Then added 27OH- to both sides and canceled the H20 to get this final equation. I also eliminted K+ because they were spectator Ions.

 

[Richnator]

Doh, Dat student just left. DOH!!!

 

[Flipper405]

Ok, I split the reaction into its oxidation and reduction components.
Reduction:
MnO4- + 4H+ + 3e- ===> MnO2 + 2H20

Oxidation:

NH3+ 3H20 ===> NO3- + 9H+ + 8e-

I eliminated the K+ cation because it is a specator ion. I then used the least common mutliple of both 3 and 8, which is 24. Therefore, I multiplied the reduction part by 8 and the oxidation part by 3.

Reduction:
8MnO4- + 32H+ + 24e- ===> 8MnO2 + 16H20

Oxidation:
3NH3+ 9H20 ===> 3NO3- + 27H+ + 24e-

Adding the two reduction and oxidation parts together, I cancel out the electrions and get:

In Acidic environment:
8MnO4- + 32H+ + 3NH3 + 9H20 ===> 8MnO2 + 16H20 + 3NO3- + 27H+

Since the top equation had OH-: I must add 32 OH- to both sides to cancel out the H+

Balanced Reaction:
8MnO4- + 3NH3 + 14H20 ====> 8MnO2 +16H20 + 3NO3- + 5OH-

Good work.

 

[Richnator]

Good work.

Thanks, tookme 10 mins to do the problem and then type it up. I didn't want to leave that question unanswered. I also doubt they would give that in the DAT. Reason being it takes too much time to do.

 

[dat_student]

I can believe I typed this whole entry up and it didnt post it. Anyway, to make it short.
This is the balanced rxn.

8MnO4- + 3NH3 +14H20 ====> 8MnO2 + 16H20 + 3NO3- + 5OH-

I initially did it as if it was a acid. Then added 27OH- to both sides and canceled the H20 to get this final equation. I also eliminted K+ because they were spectator Ions.

not right. you should have the Ks in the final balanced rxn. This question has a solution 😉

 

[Richnator]

not right. you should have the Ks in the final balanced rxn. This question has a solution 😉

8 KMnO4 + 3NH3 +14H20 ====> 8MnO2 + 16H20 + 3KNO3 + 5OH-

Haha, just to appease you.

 

[Richnator]

8 KMnO4 + 3NH3 +14H20 ====> 8MnO2 + 16H20 + 3KNO3 + 5OH-

Haha, just to appease you.

8 KMnO4 + 3NH3 +14H20 ====> 8MnO2 + 16H20 + 3KNO3 + 5KOH

 

[luder98]

Mn+7 + 3e ---> Mn+4 ------ x8
N-3 -8e ---> N+5 ---------- x3

8KMnO4 + 3NH3 -> 3KNO3 + 8MnO2 + 5KOH + 2H2O

 

[Richnator]

Mn+7 + 3e ---> Mn+4 ------ x8
N-3 -8e ---> N+5 ---------- x3

8KMnO4 + 3NH3 -> 3KNO3 + 8MnO2 + 5KOH + 2H2O

Aah, shoot. Yup, forgot to cancel out the H20's on both sides.

 

[dat_student]

Aah, shoot. Yup, forgot to cancel out the H20's on both sides.

That's the right answer.