K2SO4+ Na2HPO4=?
NaHCO3 + Sr(NO3)2=?
I don't believe either of these react. In water they will dissolve to form the corresponding ions.
An ionic exchange reaction only occurs when dissolved ions are removed from solution as (1) a precipitate (solid), (2) a gas, or (3) form a molecule that remains in the liquid phase.
Sodium- and Potassium- -Biphosphates (and -Phosphates) are soluble. Sodium- and Potassium- -Sulfates (and -Bisulfates) are soluble. No reaction occurs.
However, Strontium Carbonate is insoluble.
NaHCO3(aq) + Sr(NO3)2(aq) = SrCO3(s) + NaNO3(aq) + HNO3(aq)
I agree that SrCO3 is insoluble; however, I believe the reaction (or lack of it) will form Sr(HCO3)2 and I believe that is soluble as is Ca(HCO3)2 and Ba(HCO3)2.
Ca(HCO3) can be formed by bubbling CO2 through a suspension of CaCO3.
Ba(HCO3)2 can be formed by bubbling CO2 through a (cold) suspension of BaCO3.
Therefore, I think Sr(HCO3)2 can be formed by bubbling CO2 through a cold suspension of SrCO3 and that Sr(HCO3)2 is soluble. However, I can't confirm that. I suspect in real life that no ppt will form (or perhaps a slight haze), then with standing the solution will lose CO2 and a ppt of SrCO3 will form.
To find the products of a chemical reaction, we need to balance the equation first.
1. K2SO4 + Na2HPO4:
The balanced chemical equation for this reaction is:
2 K2SO4 + Na2HPO4 -> 2 Na2SO4 + K2HPO4
Therefore, the products of the reaction between K2SO4 and Na2HPO4 are Na2SO4 and K2HPO4.
2. NaHCO3 + Sr(NO3)2:
The balanced chemical equation for this reaction is:
2 NaHCO3 + Sr(NO3)2 -> Na2CO3 + Sr(HCO3)2
Thus, the products of the reaction between NaHCO3 and Sr(NO3)2 are Na2CO3 and Sr(HCO3)2.
It is important to note that these reactions are only valid assuming all substances are in an aqueous solution or dissolved state.