Identify the conjugate acid-base pairs in the following equations...

1. NH3 + HNO3 <---> NH4+ NO3-
Does this equation contain mostly reactants or products?

2. H2O + HBr <---> H3O+ + Br-
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3. HNO2 + HS- <---> H2S + NO2-
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4. Cl- + H2O <---> OH- + HCI
Does this equation contain mostly reactants or products?

Conjugate pairs differ by 1 hydrogen atom, usually.
NH3 and NH4 are a conjugate pair because NH3 is the base, and NH4 is the acid.
An Arrhenius or Bronsted-Lowry (BL) acid DONATES H in solution. An Arrhenius/BL base ACCEPTS H.

A LEWIS acid accepts 2 electrons (a lone pair), while a lewis base donates a lone pair.

HNO3 and NO3- are a pair because HNO3 is the acid, and NO3 is the base.

Hope this helps! :)