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.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

the electrical  conductivity  of asolution  of an electrolyte is measured by determining the resistance of thesolution  between two flat or cylindrical electrodes separated by a fixed distance.