Question

The conjugate acid of ch3nh2 is ________. the conjugate acid of ch3nh2 is ________. ch3nh2+ ch3nh2 ch3nh3+ ch3nh+ none of the above

Answer 1

The conjugate acid of ch3nh2 is ch3nh3+.
For example methylamine in water chemical reaction: 
CH₃NH₂(aq)+ H₂O(l) ⇌ CH₃NH₃⁺(aq) + OH⁻(aq).
According to  Bronsted-Lowry theory acid are donor of protons and bases are acceptors of protons (the hydrogen cation or H⁺). Methylamine (CH₃NH₂) is Bronsted base and it can accept proton and become conjugate acid (CH₃NH₃⁺).