A dilute solution of which acid is most likely to produce a reduction product other than H2 when it reacts with a metal?

A)HF
B)HCL
C)HNO3
D)H2SO4

Answer is C. I know it has something to do with it producing oxygen, but I really don't understand where that comes from. Please explain!

The most common reduction products when using HNO3 (besides H2 gas) is NO and/or NO2. VERY strong reducing agents can even produce NH3 from HNO3. but that is not nearly as common as the NO/NO2 production.

To determine which acid is most likely to produce a reduction product other than hydrogen gas (H2) when it reacts with a metal, we need to consider the reactivity series of metals and the reduction potential of each acid.

The reactivity series of metals arranges metals in order of their reactivity, from least reactive to most reactive. The series goes as follows:
Gold (Au) < Silver (Ag) < Copper (Cu) < Mercury (Hg) < Lead (Pb) < Tin (Sn) < Nickel (Ni) < Iron (Fe) < Zinc (Zn) < Aluminum (Al) < Magnesium (Mg) < Sodium (Na) < Potassium (K).

For a metal to be reduced in an acid-metal reaction, it needs to be more reactive than hydrogen (H2) based on the reactivity series.

Now let's consider the given acids:

A) HF (Hydrofluoric acid): This acid is weaker than H2SO4 and HNO3. It does not easily produce a reduction product other than H2 when reacting with a metal.

B) HCl (Hydrochloric acid): This acid is weaker than H2SO4 and HNO3. It does not easily produce a reduction product other than H2 when reacting with a metal.

C) HNO3 (Nitric acid): This acid is stronger than HF and HCl. It has the ability to oxidize metals by providing oxygen, which allows it to produce a reduction product other than H2. When it reacts with certain metals, such as copper (Cu), it undergoes a redox reaction where the copper is oxidized to copper(II) nitrate (Cu(NO3)2), and the nitric acid is reduced to nitrogen dioxide (NO2) gas.

D) H2SO4 (Sulfuric acid): This acid is stronger than HF, HCl, and HNO3. It can also produce a reduction product other than H2 when reacting with certain metals, but this is typically in the form of SO2 gas due to the reduction of sulfuric acid itself.

Therefore, out of the given options, HNO3 (Nitric acid) is most likely to produce a reduction product other than H2 when it reacts with a metal, specifically by providing oxygen to the reaction.