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How do you balance tricky chemical equations

can someone tell me their process to solve thisScreenshot 2022-01-08 2.51.50 PM.png
(edited 2 years ago)

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Original post by val7322
can someone tell me their process to solve thisScreenshot 2022-01-08 2.51.50 PM.png

Hi there.

First balance the C's so there's the same number on each side.
Then balance O.
Then balance H.

If you could show me your final equation just as a final check - that'd be great :smile:
(edited 2 years ago)
Original post by val7322
can someone tell me their process to solve thisScreenshot 2022-01-08 2.51.50 PM.png

You will need an old style weighing scale
Original post by val7322
can someone tell me their process to solve thisScreenshot 2022-01-08 2.51.50 PM.png


Prehaps not the simplest, but:

Start by assuming 1 molecule of glucose, becomes a,b,c molecules of propanone, carbon dioxide, and water respectively.

Then consider the no. of C atoms. On the left we have 6, and on the right 3a+b. Giving us one equation:

6=3a+b.

Repeat for H and O.

Solve the 3 simultaneous equations, to get an initial chemical equation.

Your values for a,b,c may be, and in this case are, fractions, so multiply through by the lowest common multiple of the denominators of any fractions to get your desired result.
(edited 2 years ago)
Reply 4
Original post by ghostwalker
Prehaps not the simplest, but:

Start by assuming 1 molecule of glucose, becomes a,b,c molecules of propanone, carbon dioxide, and water respectively.

Then consider the no. of C atoms. On the left we have 6, and on the right 3a+b. Giving us one equation:

6=3a+b.

Repeat for H and O.

Solve the 3 simultaneous equations, to get an initial chemical equation.

Your values for a,b,c may be, and in this case are, fractions, so multiply through by the lowest common multiple of the denominators of any fractions to get your desired result.

I've gotten
6= 3a +b
12 = 6a +2c
6 = a +2b +c

but i dont know how to solve three simultaneous equations
I think it's easier to think this way, the carbon compound on the right has 3 carbons, so looking at the left we have 6 carbons, so its either 1 or 2 of the CH3COCH3. Not that much work to try both, one of them doesn't work and will tell you what to put for the rest.
Original post by val7322
I've gotten
6= 3a +b
12 = 6a +2c
6 = a +2b +c

but i dont know how to solve three simultaneous equations

First you want a
From first equation we have
b = 6 - 3a. (i)
From the second equation we have
c = 6 - 3a. (ii)
Sub this into the third equation to get
6 = a + 2(6-3a) + (6 - 3a)
6 = a + 12 - 6a + 6 - 3a
-12 = - 8 a
12/8 = a
Lol are these supposed to be integers?
Well must've made a mistake but you get the overall method right?
Then you sub the value of a into (i) then (ii) to find the values of b and c
Original post by KA_P
Lol are these supposed to be integers?
Well must've made a mistake but you get the overall method right?


Read my previous post - in full.

@val7322 If you're not familiar with solving 3 simulaneous equations, then you can't use this method, though the poster above has given one way to do it. Can't see another easy method, given the oddity of this particular chemical decomposition. Perhaps you can make use of the other posters' suggestions.
(edited 2 years ago)
Ngl what I got taught to do is to make columns with the number of each element present in that molecule. And then trial by fire.

So here goes:
(1) is C6H12O6

(2) is CH3COCH3
(3) is CO2
(4) is H2O
So the total number of each element on each side should be equal therefore: (1) = (2) + (3) + (4)

(1) - C=6 ; H=12 ; O=6

(2) - C=3 ; H=6 ; O=1
(3) - C=1 ; O=2
(4) - H=2 ; O=1
I'm going to multiply (1) by 2.
So (1) - C=12 ; H=24 ; O=12
(2)+(3) [carbon] is 4 carbons. And 12/4 is 3. So let's say that (2) and (3) are potentially each multiplied by 3.
That would mean we have 18 Hydrogens in (2) now but we need 24. 24 - 18 is 6. There's 2 Hydrogens in (4) so (4) must also be multiplied by 3?
So a potential balanced equation could be:
2(1) -> 3(2) + 3(3) + 3(4)
:dontknow:
(edited 2 years ago)
Reply 9
Original post by KA_P
First you want a
From first equation we have
b = 6 - 3a. (i)
From the second equation we have
c = 6 - 3a. (ii)
Sub this into the third equation to get
6 = a + 2(6-3a) + (6 - 3a)
6 = a + 12 - 6a + 6 - 3a
-12 = - 8 a
12/8 = a
Lol are these supposed to be integers?
Well must've made a mistake but you get the overall method right?
Then you sub the value of a into (i) then (ii) to find the values of b and c

Original post by KA_P
Ngl what I got taught to do is to make columns with the number of each element present in that molecule. And then trial by fire.

So here goes:
(1) is C6H12O6

(2) is CH3COCH3
(3) is CO2
(4) is H2O
So the total number of each element on each side should be equal therefore: (1) = (2) + (3) + (4)

(1) - C=6 ; H=12 ; O=6

(2) - C=3 ; H=6 ; O=1
(3) - C=1 ; O=2
(4) - H=2 ; O=1
I'm going to multiply (1) by 2.
So (1) - C=12 ; H=24 ; O=12
(2)+(3) [carbon] is 4 carbons. And 12/4 is 3. So let's say that (2) and (3) are potentially each multiplied by 3.
That would mean we have 18 Hydrogens in (2) now but we need 24. 24 - 18 is 6. There's 2 Hydrogens in (4) so (4) must also be multiplied by 3?
So a potential balances equation could be:
2(1) -> 3(2) + 3(3) + 3(4)
:dontknow:

Wtf ur a mad brainiac too :colondollar: Can I fall harder?
Original post by Slx.24
Wtf ur a mad brainiac too :colondollar: Can I fall harder?


:blushing: it'll be more difficult to catch you 🥺

Spoiler

Reply 11
Original post by KA_P
:blushing: it'll be more difficult to catch you 🥺

Spoiler



Ur right about that :u:
Tbf, I weigh a feather so might not be that hard

Spoiler

Original post by Slx.24
Ur right about that :u:
Tbf, I weigh a feather so might not be that hard

Spoiler



😂😂 I'll go to all lengths to catch you dw :smile:


Spoiler

(edited 2 years ago)
Reply 13
Original post by KA_P
😂😂 I'll go to all lengths to catch you dw :smile:


Spoiler




Hahahaha you better get rdy cus I'm comingggg

Spoiler

Original post by Slx.24
Hahahaha you better get rdy cus I'm comingggg

Spoiler



Slxxxxxx 🙈 :rofl: - let's leave this thread railed shall we:tongue:

Spoiler

Reply 15
Original post by KA_P
Slxxxxxx 🙈 :rofl: - let's leave this thread railed shall we:tongue:

Spoiler



Damn it I nearly did it again :rofl: why do I do this everytime :cry:

Spoiler

Why would you guys derail this thread? It’s just a guy asking help on a chem question. :afraid:

Also, I condone everything that’s in post #3.
Original post by 0ptics
Why would you guys derail this thread? It’s just a guy asking help on a chem question. :afraid:

Also, I condone everything that’s in post #3.

Twas unintentional :cry:
Reply 18
Original post by 0ptics
Why would you guys derail this thread? It’s just a guy asking help on a chem question. :afraid:

Also, I condone everything that’s in post #3.

Frr 😂 Sleeps da best
Reply 19
Original post by ghostwalker
Read my previous post - in full.

@val7322 If you're not familiar with solving 3 simulaneous equations, then you can't use this method, though the poster above has given one way to do it. Can't see another easy method, given the oddity of this particular chemical decomposition. Perhaps you can make use of the other posters' suggestions.

I've done it !!!!!!!!
6= 3a +b
12 = 6a +2c
6 = a +2b +c


b = 6-3a
c=6-3a

a+ 2(6-3a) + 6-3a = 6

then

-8a +18 =6
then
8a =12
a= 12/8 = 3/2

subsitute it in b and c, which both equal 3/2

multiply everything by 2 so it would be

2C6H12O6 = 3CH3COCH3 + 3CO2 + 3H2O

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