Check attachment...Two questions on Balancing Chemical Equations...

Question

kamibug · Answer

attachment

kamibug · Answer

attachment

preetha · Answer

Kami, for the CaCl2 eq, first balance the Na on both sides!

preetha · Answer

How will you do that?

preetha · Answer

Yup.  Always start with something that is in one compound on both sides.  Now how will you balance the Cl?  You have 2 on the reactant side and 3 on the product.

preetha · Answer

Is there a coefficient you can think of? A multiple?

preetha · Answer

6.  If you multiplied CaCl2 by 3 and put 6 instead on NaCl?

preetha · Answer

I want you to learn to think through this.  Often you have to balance by trial and error.  If I do this for you, all of it, you may not learn how to do it in your test.  And I can't be there during your test...(-:

preetha · Answer

Yes!

preetha · Answer

try it and see.

preetha · Answer

Ya.  It helps if you make a table of atoms. two columns,  reactants and products.  Then write down Ca P Na and Ca on both columns.  Write down the number of atoms of each.
then see how you can multiply it out so the numbers come out right.  You can treat polyatomic ions (phosphate) as one unit.  So you have one phosphate unit on reactants side but 2 on the products.  Also when you have 2s and 3s, there will be a 6 some where.

preetha · Answer

Very good.  They love asking questions with phosphates because it has a charge of -3!

preetha · Answer

You'll be able to do the other now now.  Very similar.  H2O is HOH. So if you treat the OH- as one unit, it should be simple.