Two of the metallic compounds were used and reacted with neither the acid (hcl), nor the base (nh4oh). what were the names of the metals in those two compounds?
question 22 options:

cobalt

zinc

zn

iron

potassium

cu

fe

ca

mn

copper

co

k

manganese

vanadium

v

calcium

Copper (Cu) and Vanadium (V)

Explanation:

When the metallic compound reacts with the acid or the base, a displacement reaction will happen. So, for this happens, the metal must displace the cation (positive ion) of the other substance, and it only can occur with the metal is more reactive than the cation.

The reactivity of an element, in this case, indicates its tendency to lose electrons, so, as low is the ionization energy of a metal, easier it will be to the metal lose an electron, and more reactive it will be.

The ionization energy is a periodic property that increases from the bottom to top in the groups, and from the left to right in the periods, so the reactivity order of the metals is:

Li > K>Rb>Cs>Ba>Sr>Ca>Na>Mg>Al>Mn>Zn>Cr>Fe>Co>Ni>Pb>H>Cu>Hg>Ag>Pd>Pt>Au

The metals that are less reactivity than hydrogen (H) are called noble metals, and they generally don't react. Thus, in the reaction with HCl, the metals must displace the H, so, in the list given, the elements that can do it are Copper (Cu) and Vanadium (V), that is a noncommon metal but has ionization energy of 650 kJ, and hydrogen has 1350 kJ.

Thus, in the base, the cation NH₄⁺ has ionization energy lower than the metals, but the noble metals, are still less reactivity than it.