Question

Which two formulas represent Arrhenius acids?

(1) CH3COOH and CH3CH2OH
(2) HC2H3O2 and H3PO4
(3) KHCO3 and KHSO4
(4) NaSCN and Na2S2O3

Answer 1

The answer is (2) HC2H3O2 and H3PO4.

Answer 2

Answer : The correct option is, (2)
`HC_2H_3O_2\text{ and }H_3PO_4`

Explanation :

Arrhenius theory : It sates that an acid is a type of substance that ionizes in the water to give the hydronium ion or hydrogen ion
`(H^+)` and a bases is a type of substance that ionizes in the water to give hydroxide ion
`(OH^-)`.

Or we can say that,

Arrhenius acid are those which can easily gives the hydrogen ion in a solution and Arrhenius base are those which can easily gives the hydroxide ion in a solution.

In option 1,
`CH_3COOH` can easily gives the hydrogen ion but
`CH_3CH_2OH` can not gives the hydrogen ion due to stronger O-H bonding. So, these formulas does not represent Arrhenius acids.

In option 2,
`CH_3COOH` and
`H_3PO_4` can easily gives the hydrogen ion. So, these formulas represent Arrhenius acids.

In option 3,
`KHCO_3` and
`KHSO_4`can not gives the hydrogen ion because both are the salts. So, these formulas does not represent Arrhenius acids.

In option 4,
`NaSCN` and
`Na_2S_2O_3`can not gives the hydrogen ion because no hydrogen present in the compound. So, these formulas does not represent Arrhenius acids.

Hence, (2)
`HC_2H_3O_2\text{ and }H_3PO_4` represent Arrhenius acids.