i'm in yr 12 and i still suck at writting and balancing equations help! (1 Viewer)

[greenie1113]

i just wanted to know if you guys have any easy ways to remember what to do
cause i mean
i sometimes do get them right
but i'm not fully confident..
i am practising though
but it doesn't look like i'm getting any better..
so are there any easy ways to remember how to write them and balance equations or if there are any techniques you use to do it right
i suck at chem...my teacher sucks...but i wanna get better
please help!

 

[clue444]

get a textbook and do exercises on balancing equations, then check answers

practice a lot to get the hang of it

 

[shady145]

i just wanted to know if you guys have any easy ways to remember what to do
cause i mean
i sometimes do get them right
but i'm not fully confident..
i am practising though
but it doesn't look like i'm getting any better..
so are there any easy ways to remember how to write them and balance equations or if there are any techniques you use to do it right
i suck at chem...my teacher sucks...but i wanna get better
please help!

my teacher isnt the best either, she plays WOW instead of preparing our lesson XD
write and balance this. ethane burning in an excess of oxygen

 

[annabackwards]

As everyone has suggested just practise.

Generally, balance the carbons first and the oxygens last.

 

[squeenie]

my teacher isnt the best either, she plays WOW instead of preparing our lesson XD
write and balance this. ethane burning in an excess of oxygen

Like everyone else has said, practice is the best you can do.

The way my chemistry lecturer teaches it:

Write down the reactants (in this case, ethane and oxygen) and the products (water and carbon dioxide):

and react to form and

Put them into an equation:



Now, we'll start by balancing carbon. There are two on the left, but only one on the right. Put 2 in front of CO2 to balance it:



Next, we balance hydrogen. There are 6 on the left, and only two on the right. Put 3 in front of H2O to balance:



Finally, balance oxygen. There are seven on the right, and two on the left. Put 7/2 in front of O2 on the left to balance:



That should be right. To check it, make sure that there is the same number of each element on each side of the equation. Hope that helps

Edit: oh my, I did get it wrong. My bad. Equation has been fixed.

 

[annabackwards]

^
Excellent working out, squeenie except that there are 7 oxygens on the right so there should be a 7/2 in front of the O2 on the LHS.

 

[squeenie]

^
Excellent working out, squeenie except that there are 7 oxygens on the right so there should be a 7/2 in front of the O2 on the LHS.

Yeah, I still practice a lot for chemistry too. Doing it all over again in uni makes me realise how easy HSC chemistry was >_>

Edit: fixed equation. I knew something was wrong, but wasn't sure what Thanks for pointing it out.

 

[adomad]

you first balance the metals, then the non-metals then hydrogen then oxygen.. seems to work for me

sorta like what squennie said
and it should be



opps didn't notice that someone already pointed it out. another point is that you can't balance an equation with a fraction (7/2) if it isn't diatomic.

 

[squeenie]

you first balance the metals, then the non-metals then hydrogen then oxygen.. seems to work for me

sorta like what squennie said
and it should be



opps didn't notice that someone already pointed it out. another point is that you can't balance an equation with a fraction (7/2) if it isn't diatomic.

Yeah, writing it that way makes it easier to read. It usually doesn't matter which way you write it, but most teachers will tell you to multiply the equation to get rid of the fractions.

 

[Dragonmaster262]

In my test I had this weird equation which we had to write as a balanced symbol equation.

Copper + nitric acid --->copper(2) nitrate + nitrogen dioxide + water

Is this equation even possible?

 

[annabackwards]

In my test I had this weird equation which we had to write as a balanced symbol equation.

Copper + nitric acid --->copper(2) nitrate + nitrogen dioxide + water

Is this equation even possible?

Cu + HNO3 --> Cu(N03)2 + NO2 + H20

I can't seem to balance it ><"

 

[squeenie]

Cu + 3HNO3 --> Cu(N03)2 + NO2 + H20

I can't seem to balance it ><"

Still trying to balance the equation, but yeah, it's an example of a metal/acid reaction.

 

[shady145]

1:4---1:2:2

 

[shady145]

or if u didnt understand what those numbers means lol
Cu + 4(HNO3)-------->Cu(NO3)2 +2(NO2) + 2(H2O)

 

[squeenie]

1:4---1:2:2

So that'd make it:



Awesome, nice work.

 

[shady145]

So that'd make it:



Awesome, nice work.

we can call it a team effort between you, me n anna =)
or if someone wants to correct me, you, anna and I. haha

 

[Dragonmaster262]

Still trying to balance the equation, but yeah, it's an example of a metal/acid reaction.

Isn't acid + metal-----> salt + hydrogen? If that's true than this equation is impossible.

 

[annabackwards]

we can call it a team effort between you, me n anna =)
or if someone wants to correct me, you, anna and I. haha

Oh, awesome work! I forgot that you couldn't change 2 the Cu(NO3)2... no wonder it didn't work out XD

Isn't acid + metal-----> salt + hydrogen? If that's true than this equation is impossible.

That is true, but i think your teacher just wanted to know if you could balance something other than the standard reactions.

 

[autumn-angel]

I think there is an algebraic method to balancing chemical equations, but I don't know if that works in every case...

 

[Pwnage101]

there is. Using matrices (first year uni maths) helps out, but its is still possible to do without such knowledge.

justlet w, x, y and z, for example, be the molar ratios of each species, eg:

w C2H5OH (l) + x O2 (g) ----> y CO2 (g) + z H2O(l)

and just create a number of simultaneous equations using teh fact that the number of atoms of one element on the left must equal the number on the right, for eg:

2w = y for the C atom

6w = 2z for H atom

w + 2x = 2y + z for O atom

then putting in w for y and z

w + 2x = 2(2w) + 3w

ie w + 2x = 7w

2x = 6w

x = 3w

let w = 1 (will give smalles possible integer set for w, x, y, z)

thus w = 1, x = 3, y = 2, z = 3

thus equation becomes:

C2H5OH (l) + 3O2 (g) ----> 2CO2 (g) + 3H2O(l)

then again i would advise AGAINST using this method in exams, just do it in your head! much, much quicker and easier.

HINT: always do species on LHS and RHS that contain all of one lemenmt on that side

eg in the above example on the LHS ethanol had all Carbons on the left, and carbon dioxide all on the right

thus no matter what values we get, we know that the molar ratio of CO2 MUST BE TWICE the molar ratio of the ETHANOL for it to balance.

same with the H's - we know the molar ratio of H2O MUST BE THREE TIMES that of ethanol.

that gets u:

1 x 2 3

then u can work out how much O is needed, and if u end up witha fraction (eg 7/2) u just doube every term

hope that helps