Question

HA and HB are two strong monobasic acids. 25.0cm3 of 6.0mol/dm3 HA is mixed with 45.0cm3 of 3.0mol/dm3 HB.

What is the H+ (aq) concentration in mol/dm3 in the resulting solution ?


A 1.9

B 2.1

C 4.1

D 4.5


If anyone could explain how to reach an answer that would be so helpful !!

Answer 1

The H+ (aq) concentration of the resulting solution is 4.1 mol/dm³

(Option C)

Step-by-step explanation:

Given;

concentration of HA,
`C_A` = 6.0mol/dm³

volume of HA,
`V_A` = 25.0cm³, = 0.025dm³

Concentration of HB,
`C_B` = 3.0mol/dm³

volume of HB,
`V_B` = 45.0cm³ = 0.045dm³

To determine the H+ (aq) concentration in mol/dm³ in the resulting solution, we apply concentration formula;

`C_iVi = C_fV_f`

where;

`C_i` is initial concentration

`V_i` is initial volume

`C_f` is final concentration of the solution

`V_f` is final volume of the solution

`C_iV_i = C_fV_f\\\\Based \ on \ this\ question, we \ can \ apply\ the \ formula\ as;\\\\C_A_iV_A_i + C_B_iV_B_i = C_fV_f\\\\C_A_iV_A_i + C_B_iV_B_i = C_f(V_A_i\ +V_B_i)\\\\6*0.025 \ + 3*0.045 = C_f(0.025 + 0.045)\\\\0.285 = C_f(0.07)\\\\C_f = (0.285)/(0.07) = 4.07 = 4.1 \ mol/dm^3`

Therefore, the H+ (aq) concentration of the resulting solution is 4.1 mol/dm³