I need help writing a balanced eqaution for the following reactions?

Question

1) copper II nitrate is dissolved in 100ml of deionized water

*** i dont think the measurement matters ***

2) ammonia gas is bubbled through cold deionized water

3) a solution of silver nitrate is added to a solution of potassium carbonate

Answer 1

The first one is the salvation of a solid. The solid goes into aqueous phase. Don't for get the sign conventions solid (s) aqueous (aq) Water is usually written above the arrow (no between) and not as a reactant because water would be present on both sides of the equation.

1) Cu(NO3)2(s) ---H2O--> Cu(NO3)2(aq)

The second one a gas is going into the aqueous phase. The sign convention for a gas is (g). Water is written in the same way as in the first equation.

2) NH3(g) ---H2O--> NH3(aq)

This type of reaction is called a precipitation reaction. Two salts in the aqueous phase are mixed to form a precipitate (solid) and a different aqueous salt. Write the aqueous salt with the correct sign conventions. To find out which salt precipitates, look at a solubility table. Just as a rule alkali metals, NH4+, and NO3- are highly soluble (so they are not precipitates). Precipitates are usually heavy metals like lead, silver, as many more.  

3) 2AgNO3(aq) + K2CO3(aq) --> Ag2CO3(s) + 2KNO3(aq)

There's not right or wrong way to balance equations. What I like to do is balance the heavy metals first, then balance the rest. You kinda have to fiddle with the coefficients till the number of atoms balance.

Answer 2

deionized means that it is pure water.

1. When dissolving a soluble salt in water  the results is the productions of separate ions. You need to put the numbers as subscripts and the charges as superscripts

Cu (NO3)2  --------------------------Cu +2    +  2 NO3-1

2. NH3 + HOH ----------------------  NH4OH  (Know this rx--)

3. 2AgNO3  +  K2CO3--------------------------Ag2CO3    +  2KNO3

Both salts are soluble--- you need to know the solubility rules—find them using yahoo search if you don’t have a list.

Nitrate and K salts are always soluble.  

Since the two compounds are soluble--- they will each break into separate ions--- silver, nitrate, potassium, and carbonate.  Now recombine them showing two new ways the ions can combine—remember that only + ions combine with – ions.

First—correctly write the formulas of the new compounds considering their charges.

Then balance the equation.

Answer 3

3) AgNO3 + K2CO3 = Ag2CO3 + KNO3

2) NH3 (g) + H20 = (equilibrium sign) NH4+  + OH-

As to question number one, look for the solubility rules. It is soluble in water, forms pale blue solution due to presence of copper 2+ ions.

Cu(NO3)2 + H2O = ?