My chemistry homework...

[saudade]

H3PO4(aq) + Mg(OH)2 -> H20 + MgPO4

Can someone please balance that for me? It's a real crazy one... Unless I'm missing something...

[Exhumed]

You can do it yourself... :p

[Chatha]

18014398509481988H3PO4 + 3Mg(OH)2 -> 2702159776422298H20 + 18014398509481980MgPO4

http://www.geocities.com/junebug_sophia/equBal.htm

[saudade]

You can do it yourself... :p

You, mademoiselle, (I'm assuming) are not very helpful. ;)

[Exhumed]

18014398509481988H3PO4 + 3Mg(OH)2 -> 2702159776422298H20 + 18014398509481980MgPO4

http://www.geocities.com/junebug_sophia/equBal.htm

That was a joke, right? :p

[Exhumed]

You, mademoiselle, (I'm assuming)

no

are not very helpful. ;)

People should generally do their own homework. These type of homework problems are math problems anyway, and basic math, so you have the ability to figure it out.

[inzomnia]

H3PO4(aq) + Mg(OH)2 -> H20 + MgPO4

Can someone please balance that for me? It's a real crazy one... Unless I'm missing something...


here is a hint: not MgPO4 ;) after you figure out what is the
correct form of magnesium phosphate, you can balance it easily.

here is another hint:
* how many H is equivalent to PO4 in H3PO4?
* How many OH is equivalent to Mg in Mg(OH)2?
* so, how many Mg and PO4 required to form magnesium phosphate?

ok now thats too much hint.

[Positron]

aye, your "MgPO4" is not right, make sure your looking at charges on both the ions

[TruthSeeker]

Fuck! I remember studying a lot of those things at school and now I can't remember anything... :(

[MetaKron]

H3PO4(aq) + Mg(OH)2 -> H20 + MgPO4

Can someone please balance that for me? It's a real crazy one... Unless I'm missing something...

The magnesium phosphate is wrong. As I thought the magnesium has a valence number of plus 2 and the phosphate radical is minus 3. I'm worried that this may be the way that it appears in the book, that the student may have to try to balance the equation for an incorrect formula for magnesium phosphate.

I would think that this would be a "fill in the blanks" for how many molecules of each goes in and comes out, but the right hand side has the wrong formula for the phosphate, so it won't come out right until that is corrected. There are actually enough clues on the left side to correct the right side. But when a student reads it, does he know for sure which part he should change the numbers on?

[inzomnia]

Ok I'll try to explain the concept.

acid + base ---> water + salt

acid: HxA, for example: H2SO4
where: A = SO4, x = 2

base: B(OH)y, for example: Al(OH)3
where: B = Al, y = 3

salt: BxAy, in this case: Al2(SO4)3

To balance:

mHxA + nB(OH)y ---> pH2O + qBxAy

the number of A, B, O, and H should be balance in both side.

To start easily, balance the A and B first, follow by O and H:
for A: m = qy
for B: n = qx
for O and H, just solve the rest for p and q

so: 3H2SO4 + 2Al(OH)3 ----> Al2(SO4)3 + 6H2O

I hope that helps.

p.s: busy, but I'll be back. Bye

[TruthSeeker]

Thank you very much, inzomnia. That reminds me a little bit about how those things work.... I still have to remember how many free electrons each substance have.... Isn't there a way you can find that out when looking at the periodic table.....? I think it's the position where they are in the table, isn't that right?

[saudade]

I did get it eventually without help from you lovely people... And I did eventually figure out that Mg was supposed to be Mg3. I already got a 100% on a balancing equations test, but this was a reactions take home test. Chemistry is interesting and all, but it gets REAL tiresome sometimes...

[dexter]

Wouldnt there just be 2H2O in the yield? I havent taken general chem in years.