What is a solvent called which is neither proton donor nor proton acceptor?

Refer to the given graph showing state of ionisation of zwitterion. Select the correct statements regarding zwitterion. (i) Zwitterions can be formed from compunds that contain both acid groups and basic groups in their molecules. (ii) A zwitterion can act either as proton donor or proton acceptor. (iii) A monoamine monocarboxylic alpha -amino acid is a acid at high pH as both the groups (amino and carboxyl) lose a proton. (iv) Amino acids in solution at neutral pH exist predominantly as dipolar ions, the amino group is protonated (-NH_(3)^(+)) and the carboxyl group is deprotonated (-COO^(-)) .

The number which is neither prime nor composite is

Assertion (A): pK_(a) of a weak acid become equal of the pH of the solution at the mid-point of titration. Reason (R) : The molar concentration of the proton donor an proton acceptor beomes equal at the mid-point.

What is the value of mass and charge on the proton ?

Oxide of a non-metal possesses the following characteristics (i) It is both a proton donor and an acceptor (ii) It is a poor conductor of electricity (iii) It reacts readily with basic and acides (iv) It oxidises Fe at its boiling point.This oxide is