balancing the following equations?

Question

please help me balance the following equation *step by step*
___H3PO4 + ___KOH ---> ___K3PO4 +___H2O

Answer 1

When balancing equations that contain polyatomic ions (which this equation does), it is often easier to balance if you balance the polyatomic ions as if they were a single entity (this is the way they "travel"). To do this, look at your equation. Do you have PO4 on both sides of the equation? Do you have OH on both sides of the equation? You probably are saying to yourself right now that yes, you have PO4 on both sides but NOT OH. Heh, heh! Oh, yes you do! Show your water as HOH instead of H20. NOW you have OH on both sides!

I like to set up a chart showing the individual elements/polyatomic ions on both sides of the equation. Then I look at what is balanced and what is not. Those that are NOT balanced then are where you are going to start. You balance by using coefficients. Let's start. (I will have to use ..... to keep my chart lined up as this program will run everything together if I don't.) I will put () around the polyatomic ions so you can see what I am keeping together. DO NOT COUNT THE ELEMENTS IN THE POLYATOMIC IONS WHEN COUNTING SEPARATE ELEMENTS.

H3(PO4)+ K(OH) --> K3(PO4) + H(OH)

E = ELEMENT OR POLYATOMIC ION
R = REACTANT SIDE
P = PRODUCT SIDE

E____R___P
----------------
H.......3......1
PO4...1......1
K........1......3
OH.....1......1

Now you can see that the hydrogen is out of balance and the potassium is out of balance. To balance the hydrogen, put a coeffient of 3 in front of the H(OH). Change your numbers in your chart to reflect this change.

You now have:

H........3...3
PO4...1...1
K.......1....3
OH....1.....3

Now balance your K by putting a coefficient of 3 in front of your KOH and then recount your atoms. You now have:

H...........3......3
PO4.......1.....1
K...........3......3
OH........3......3

You are balanced.

Your equation is:

H3PO4 + 3KOH --> K3PO4 + 3H2O

This method can be used for ANY equation. Your trick is being able to identify your polyatomic ions. You can keep them together if they are on both sides of the equation. If they are NOT on both sides of the equation then you have to count them as single elements. Putting () around your polyatomic ions is helpful in spotting this. You also must make sure that if you have a polyatomic ion that has a subscript such as (PO4)3, then make sure you count the PO4 as "3".

Hope this helps!

When balancing equations with poly atomic tions. Balance your indivudal elements FIRST. I started with Hydrogen, but it is usually best to start with elements other than hydrogen first. Then do the other single elements. This usually is all it takes to balance the polyatomic ions.

CHEMISTRY TEACHER

Answer 2

Well, first balance your Ks. You have three on the products (RIGHT) side, but only one on the reactants (left) side. So, put a 3 before KOH. Now you have three potassiums on each side. Now, check your Hydrogens. You have 3 in the H3PO4 and 3 in the KOH, meaning you have a total of 6 on the reactant side. You have two hydrogens on your product side (the H2O). So, you need to put a 3 before the H2O so that you have six hydrogens on your product side and your reactant side. Now check your oxygens. You have seven on your reactant side and seven on your product side, meaning they are balanced. So your final equation should read: H3PO4+ 3KOH---> K3PO4+3H2O...........Be sure not to put 1s in front of the H3PO4 and K3PO4. It's incorrect to fill in the empty spaces when a 1 belongs there; ones are understood.

Answer 3

H3PO4 +3KOH=K3PO4+3H2O

Answer 4

1_H3PO4 + 3_KOH ---> 1_K3PO4 +3_H2O

hope it helps!!