College Board SAT II Chem Question

Test Preparation SAT Subject Test Preparation
1

<p>Which of the following does NOT react with a dilute H2SO4 solution?
(A) NaNO3
(B) Na2S
(C) Na3PO4
(D) Na2CO3
(E) NaOH</p>

<p>Why is the answer (A)? Also, I have not taken AP Chemistry, only Honors, so I need a simple explanation. </p>

<p>Someone told me it's NaNO3 because: </p>

<p>"The answer is A because of solubility rules. For a reaction to occur something has to be produced, or be insoluble. Na is always soluble, so it isn't the deciding factor of the question. S, PO4 and CO3 are almost always insoluble, which means the reaction would occur here. OH would just produce H2O meaning the reaction would also occur. NO3 is ALWAYS soluble, so the reaction between H2SO4 and NaNO3 would produce nothing meaning there is no reaction."</p>

<p>"Insoluble just means something solid basically. Not sure if I made that clear or not. NaSO4 is not actually being produced, Na^+ and SO4^-2 are just floating around the solution because they are soluble. HNO3 is also not being produced because NO3 is also soluble."</p>

2

<p>I don’t think it has to do with solubility. All the rest of the compounds except NaNO3 are basic b/c they contain the conjugate base of a weak acid so they should react with the strong acid H2SO4. However, NaNO3 is neutral b/c Na ion is the conjugate acid of a strong base (NaOH) and NO3 ion is the conjugate base of a strong acid (HNO3). Therefore, NaNO3 is neutral and will not react with a strong acid.</p>