Question

Which of these substances is an arrhenius acid?

a. c2h6(g)

b. ch4(g)

c. hbr(g)

d. koh(s)e. na3po4?

Answer 1

The answer to this question would be: c. HBr(g)

Arrhenius concept of acid is the molecule that will form hydrogen ion when dissolved in aqueous solution. Hydrogen bromide of HBr will form a hydrogen ion and a bromide ion.
Kalium hydroxide or KOH will release OH- ion so it would be a base.