Question

Beaker #1: HNO3

Beaker #2: HNO2

Beaker #3: HCl

Each beaker contains 100 ml of the indicated acidic solution, all are at ph=3. Ka HNO2= 4x10^-4

1. a) Beaker 2 has the lowest percent ionization. Explain why.

b) Beakers 1 & 3 have the same molarities, and this molarity is less than that of Beaker 2. Explain why.

Answer 1

1) HNO2 is weak acid

it means it will not dissociate completely as its ka is small.

at same concentration strong acids will dissociate completely where as weak acids dissociates partially.

2) same pH means same concentration of H⁺ ions. as we know HNO2 is weak acid it will not dissociate completely.

but H⁺ concentration is same in all three solutions.

it means we should take more concentration Of HNO2 than HCl and HNO3 to give same amount of H⁺.

so molarities of HCl and HNO3 are less than HNO2