double replacement rections?

Question

here's the question, but actually, if you could point me to a website that explains it, that would be really nice!! Thanks in advance!

DIRECTIONS:Predict and balance the following metathesis reactions based on the solubility of the products. Use abbreviations (aq) and (s) for the reactants and products. All reactants and products. All reactants are aqueous.

1) silvernitrate+potassium chromate

2) ammonium chloride+cobalt(II) sulfate

Answer 1

Your text book should be a good source to use to answer your question. These are "double replacement" reactions where the positive part of each compound switch places. I assume you need help deciding if a product is soluble (forms a precipitate) or not. General rules of solubility are:

1. All NO3(-1), ClO4(-1), ClO3(-1), CH3COO(-1) and NH4(+1) compounds are soluble
2. All group1 (alkali metal) compounds are soluble
3. All Cl(1-), F(1-), Br(1-) compounds are soluble EXCEPT Ag, Pb, Hg
4. All SO4(-2) compounds are soluble EXCEPT Ag,Pb,Hg and Ca, Sr, Ba.
5. All strong acids are soluble (HNO3, H2SO4, HBr, HI, HCl, HClO3, HClO4)
6. All strong bases are soluble (group 1 and group 2 except Be, Mg)

Pretty much anything else will not dissolve and forms a precipitate.

In the first reaction the products are silver chromate (not on the list and therefore will precipitate) and potassium nitrate (nitrate and potassium are both on the solubility list so it will not precipitate).

In the second reaction the products are ammonium sulfate (ammonium is on the solubility list so this will not precipitate) and cobalt chloride (most chlorides are soluble so this will not precipitate either). This represents no reaction since no new products will form.

2AgNO3(aq) + K2CrO4(aq) = Ag2CrO4(s) + 2KNO3(aq)

2NH4Cl(aq) + CoSO4(aq) = (NH4)2SO4(aq) + CoCl2(aq)

Answer 2

the previous answer is inaccurate, valences are incorrect, nitrate has grow to be nitrite, etc. - balanced, it may be 2AgNO3 + BaCl2 = 2AgCl + Ba(NO3)2 BTW, one made from this equation is almost the medium for black and white pictures (exposure of AgBr to easy breaks all of it the way down to elemental silver, appearing on the image paper). B

Answer 3

See the following site, whih breaks it down well. You will need your solubility table (unless you are supposed to memorize).

http://dbhs.wvusd.k12.ca.us/webdocs/Equations/DoubleReplacement.html

The first few paragraphs are wordy, but the example are great.

also see the excellent site:

http://www.chemtutor.com/react.htm#double

Answer 4

1. NaNO3(aq) + K2CrO4(aq) = KNO3 + Na2CrO4

2. NaOH4Cl + CoSO4 = (NaOH4)2SO4 + CoCl2

i'm not sure, hahha. i'm only a first year high school student! ^_^