Identify the correct acid and conjugate base pair in this equation: hno2 + hs - --> no2- + h2s

Acid: HNO₂

Conjugate base: NO₂⁻

Base:  HS⁻

Conjugate acid:  H₂S

Explanation:

HNO₂ + HS⁻  →   NO₂⁻ + H₂S

This is the reaction of nitrous acid with hydrosulfide, to generate nitrite and  sulfide acid.

HNO₂ is a weak acid that release the proton to the HS⁻, so the HS⁻ is the base.

Proton that is caught by the HS⁻, produce the H₂S so, if the HS⁻ is the base (accepts a proton from other compound), the H₂S acts like the conjugate acid.

In nitrous acid, which is behaving as an acid (a weak one), the nitrite becomes in the conjugate strong base.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.