AP Notes, Outlines, Study Guides, Vocabulary, Practice Exams and more!

# Double Displacement Help

6 posts / 0 new
Offline
Joined: Oct 2005
Double Displacement Help

I have no clue how to do the double displacement method thing so if anyone wants to help me that would be great :-)

The question is:
Write the complete ionic equation for the double displacement reaction that occurs when aqueous solutions of barium nitrate, Ba(NO3)2 and sodium chromate (Na2CrO4) are mixed.

I didn't understand it when we did it in class and when I went to her for help she refused to help me

<3 Ashley

Offline
Joined: Sep 2005

First of all, double replacement not double displacement.

Ba(NO3)2 + Na2CrO4 => NaNO3 + BaCrO4 I believe.. Then cancel spectator ions then you got your net ionic equation.

Offline
Joined: Mar 2005

Armando wrote:First of all, double replacement not double displacement.

Ba(NO3)2 + Na2CrO4 => NaNO3 + BaCrO4 I believe.. Then cancel spectator ions then you got your net ionic equation.

You forgot to balance it, but the method is correct. There should be a two in front of NaNO3

[=RoyalBlue][=Comic Sans MS]
"I refuse to prove that I exist," says God, "for proof denies faith, and without faith I am nothing."
"But," say Man, "the Babel fish is a dead giveaway, isn't it? It could not have evolved by chance. It

Offline
Joined: Sep 2005

Correct, I accidentally oversaw that ;)

Offline
Joined: Oct 2005

Armando wrote:First of all, double replacement not double displacement.

Ba(NO3)2 + Na2CrO4 => NaNO3 + BaCrO4 I believe.. Then cancel spectator ions then you got your net ionic equation.

Thanks. And it can be called double displacement. Its either or.

<3 Ashley

Offline
Joined: Nov 2005

Write the complete ionic equation for the double displacement reaction that occurs when aqueous solutions of barium nitrate, Ba(NO3)2 and sodium chromate (Na2CrO4) are mixed.

Since nitrates and alkali metals are always soluble, the reactants should have been broken up into ions.

Ba 2+ + NO3 - + Na + + CrO4 2-

Then switch the ions over, hence double replacement, to get

Ba 2+ + CrO4 2- + Na + + NO3 -

BaCrO4 is insoluble, so it should be written as BaCrO4 (s) while NaNO3 is soluble, so it should still be written as two ions in the product side as Na + and NO3 -. Since Na + and NO3 - appear on both sides of the equation, you can cancel them out and the final complete ion reaction is

Ba 2+ + CrO4 2- --> BaCrO4 (s)

## Need Help?

We hope your visit has been a productive one. If you're having any problems, or would like to give some feedback, we'd love to hear from you.

For general help, questions, and suggestions, try our dedicated support forums.

If you need to contact the Course-Notes.Org web experience team, please use our contact form.

## Need Notes?

While we strive to provide the most comprehensive notes for as many high school textbooks as possible, there are certainly going to be some that we miss. Drop us a note and let us know which textbooks you need. Be sure to include which edition of the textbook you are using! If we see enough demand, we'll do whatever we can to get those notes up on the site for you!