Need help on balancing chemical equations (1 Viewer)

[Speed6]

This is a worksheet on balancing chemical equations. It was one of the last few questions I left out because I wasn't too sure on how to approach it. The (OH)2 part is the one that confused me.

Thanks.

 

[Librah]

2 infront of hcl and 2 infront of water. Done. LHS should have same type/number of molecules are RHS. 1Pb 4H 2O 2Cl

 

[Speed6]

2 infront of hcl and 2 infront of water. Done. LHS should have same type/number of molecules are RHS. 1Pb 4H 2O 2Cl

Ty

 

[Speed6]

2 infront of hcl and 2 infront of water. Done. LHS should have same type/number of molecules are RHS. 1Pb 4H 2O 2Cl

Yun, can there ever be equations that can't be balanced?

 

[Librah]

Yun, can there ever be equations that can't be balanced?

Can't happen IRL if it can't be balanced. And some that can be balanced rarely ever happen, and must happen under specific conditions.

 

[Speed6]

What would this (SO4)3 mean? (Part of a question for balancing equations)

 

[InteGrand]

That means there's three sulfate ions.

For balancing purposes, that's 3 S's and 12 O's.

 

[Librah]

What would this (SO4)3 mean? (Part of a question for balancing equations)

It's just structural formula, it's structured so that there are 3 SO4 grps for every 2 Aluminium. So when you see the actual full chemical structure for the chemical, it won't be like a random 3S and O12 scattered randomly. I think for the chemical here, it's soluble in water, so you'll have 2 Al ions for every 3 SO4 ions in water, instead of S and O molecules seperated in the solution. Look up the full structural formula for it, and you'll see why it's (so4)3, the SO4 grp itself has a pretty specific structure (has 2 double bonds iirc). Ah yer this was a really dodgy explanation lol

 

[Speed6]

It's just molecular formula, it's structured so that there are 3 SO4 grps for every 2 Aluminium. So when you see the actual full chemical structure for the chemical, it won't be like a random 3S and O12 scattered randomly. I think for the chemical here, it's soluble in water, so you'll have 2 Al ions for every 3 SO4 ions in water, instead of S and O molecules seperated in the solution.

If you broke it up and joined it together would it be Al2S3O12?

 

[Librah]

If you broke it up and joined it together would it be Al2S3O12?

In that specific structure? No, but yes it does have 2 Al 3S and 12 O. Theres 2 double bonds between S and O in SO4, if you broke it down and rearranged it, it just won't have the same number of molecules for it to be stable.

 

[Speed6]

In that specific structure? No, but yes it does have 2 Al 3S and 12 O.

You are right and btw I just needed to make it simpler to work with. I dunno how you balance equations but I balance them a different way lol. So the 2 Al S3 O12, all broken down help me.

 

[Librah]

You are right and btw I just needed to make it simpler to work with. I dunno how you balance equations but I balance them a different way lol. So the 2 Al S3 O12, all broken down help me.

I usually just balance it in my head. Just ensure there are the same number of elements on both sides of the equation.

 

[Speed6]

I usually just balance it in my head. Just ensure there are the same number of elements on both sides of the equation.

Thanks for helping me, appreciate it. I'm guessing that you did chemistry as well and you liked it?

 

[Librah]

Thanks for helping me, appreciate it. I'm guessing that you did chemistry as well and you liked it?

Yer Chem was prob the only subject i had a motivating teacher lol, even though he wasn't around for the entire 1st term and most of 2nd term.

 

[InteGrand]

If you can't quickly see by inspection what coefficients to place when balancing, you can always put generic pronumerals A, B, C etc. (one in front of each species in the chemical equation), and without loss of generality, make the coefficient of the first species 1.

Then you can compare the no. of a given element on each side of the chemical equation, and if you do this for each element, you'll end up with a system of linear equations which will be solvable, provided that the initial chemical equation can indeed be balanced (which it always will we able to in Preliminary and HSC Chemistry).

You might end up with fractional coefficients (since you're letting the first species have coefficient 1), but this won't matter, since once you have the solution, if necessary, you can multiply through by the lowest common multiple of the denominators.

 

[Silly Sausage]

Using gaussian elimination/matrices should be your last resort LOL

 

[Librah]

If you can't quickly see by inspection what coefficients to place when balancing, you can always put generic pronumerals A, B, C etc. (one in front of each species in the chemical equation), and without loss of generality, make the coefficient of the first species 1.

Then you can compare the no. of a given element on each side of the chemical equation, and if you do this for each element, you'll end up with a system of linear equations which will be solvable, provided that the initial chemical equation can indeed be balanced (which it always will we able to in Preliminary and HSC Chemistry).

You might end up with fractional coefficients (since you're letting the first species have coefficient 1), but this won't matter, since once you have the solution, if necessary, you can multiply through by the lowest common multiple of the denominators.

........ If i can't balance a chemical equation in less than 15 secs, i'll just skip it and leave for later. Don't think anyones gonna do that rofl.

 

[suika]

........ If i can't balance a chemical equation in less than 15 secs, i'll just skip it and leave for later. Don't think anyones gonna do that rofl.

Not wise.

At least spend a minute on it. You don't know how long it'll take you to complete other sections (such as those wonderful 6 mark questions about the environment) + you're risking the chances of losing a mark.

 

[Librah]

Not wise.

At least spend a minute on it. You don't know how long it'll take you to complete other sections (such as those wonderful 6 mark questions about the environment) + you're risking the chances of losing a mark.

Haven't encountered an equation that i actually required 10+ secs to balance, just saying if you can't balance just leave it for later.