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The pH is determined by the hydrolysis of the salt. The proper way to do this is to solve for Kb or Ka and compare but I have an easier way to do. Your prof may or may not approve but it gets the answer every time, takes less time, BUT may not be up to snuff with theory.
NH4NO3 + HOH ==> NH4OH + HNO3
KBrO3 + HOH ==> KOH + HBrO3
RbCN + HOH ==> HCN + RbOH
Now you look at the equations. I'll choose the last one.
HCN is a weak acid and RbOH is a strong base; therefore, the solution will be basic. A pH of 5.19 is acidic so this one can't be right. Now you go through the other two tghe same way. Pick the one that is acidic. Post your work/thinking if you get stuck.By the way, you may know NH4OH as NH3 + H2O.
You are given an aqueous salt solution and have determined that its pH is 5.19 at 25°C. Predict which of the following three salt solutions it is most likely to be.
solution (1): a solution of ammonium nitrate (NH4NO3)
solution (2): a solution of potassium bromate (KBrO3)
solution (3): a solution of rubidium cyanide (RbCN)
1 answer