HA and HB are two strong monobasic acids.
25.0cm3 of 6.0moldm–3 HA is mixed with 45.0cm3 of 3.0moldm–3 HB.
What is the H+(aq) concentration, in mol dm–3, in the resulting solution? A 1.9
B 2.1
C 4.1
D 4.5
could you please explain how you reach an answer
Molarity = M = mols/dm^3 = millimols/cc so you find the millimols of HA and the millimols of HB, add them for the total and divide by the total cc,
mmols HA = cc x M = 25.0 x 6.0 = ? 150?
mmols HB = 45.0 x 3.0 = ? = 135?
total millimols = 150 + 135 = 285
total cc = 25.0 + 45.0 = 70?
total (H^+) = 285/70 = ? M
Sure, but before I explain, let me just say that you've entered the "Acid Zone"! Alright, let's dive in.
To find the H+(aq) concentration in the resulting solution, we can use the principle of conservation of moles. According to this principle, the total moles of H+(aq) before and after the reaction should be equal.
The equation for the reaction between HA and HB can be written as:
HA + HB → H+(aq) + A-(aq) + B-(aq)
From the balanced equation, we can see that one mole of HA reacts with one mole of HB to form one mole of H+(aq). Therefore, the number of moles of H+(aq) formed will be equal to the number of moles of HA or HB present initially.
First, let's calculate the number of moles of HA and HB in the initial solutions:
Number of moles of HA = concentration × volume
= 6.0 moldm–3 × 0.025 dm3
= 0.15 mol
Number of moles of HB = concentration × volume
= 3.0 moldm–3 × 0.045 dm3
= 0.135 mol
Since the reaction between HA and HB is 1:1, the number of moles of H+(aq) formed will be equal to the number of moles of HA or HB, which is 0.15 mol.
Now, let's calculate the concentration of H+(aq) in the resulting solution:
H+(aq) concentration = moles/volume
= 0.15 mol / (0.025 dm3 + 0.045 dm3)
= 0.15 mol / 0.07 dm3
= 2.1 moldm–3
So, the correct answer is B 2.1 moldm–3.
I hope that explanation made your brain cells do a little "acidic dance"!
thanks for the help
np
deez nuts
To find the H+(aq) concentration in the resulting solution, we can use the concept of moles and the principle of conservation of mass.
First, let's find the moles of HA and HB present in the given solutions:
Moles of HA = concentration of HA × volume of HA
= 6.0 mol/dm³ × 0.025 dm³ (25.0 cm³ is equivalent to 0.025 dm³)
= 0.150 mol
Moles of HB = concentration of HB × volume of HB
= 3.0 mol/dm³ × 0.045 dm³ (45.0 cm³ is equivalent to 0.045 dm³)
= 0.135 mol
Since both HA and HB are monoprotic acids, they will ionize completely in the solution, resulting in the same number of moles of H+ ions.
Therefore, the total moles of H+ ions in the resulting solution are equal to the sum of the moles of HA and HB:
Total moles of H+ ions = Moles of HA + Moles of HB
= 0.150 mol + 0.135 mol
= 0.285 mol
Finally, to find the H+(aq) concentration, we divide the moles of H+ ions by the total volume of the resulting solution:
H+(aq) concentration = Total moles of H+ ions / Total volume
= 0.285 mol / (25.0 cm³ + 45.0 cm³) (convert to dm³)
= 0.285 mol / 0.070 dm³
= 4.07 mol/dm³
Rounding to one decimal place, the H+(aq) concentration in the resulting solution is approximately 4.1 mol/dm³.
Therefore, the correct answer is option C: 4.1.