Answer:
Step-by-step explanation:
H₃O⁺ and H₂O .
H₂O + H⁺ ⇄ H₃O⁺
H₂O accepts proton to form H₃O⁺ so H₂O is base .
H₃O⁺ ⇄ H₂O + H⁺
Here H₃O⁺ is acid because it gives proton ( H⁺ ) .
HCO₃ ⁻ and H₂CO₃
H₂CO₃ ⇄ HCO₃ ⁻ + H⁺
H₂CO₃ is acid because it gives proton ( H⁺ )
HCO₃ ⁻ + H⁺ = H₂CO₃
HCO₃ ⁻ is base because it accepts proton .