Calculate the hydronium ion (H_3O^+) concentration in a 0.30 M aqueous solution

Question

Calculate the hydronium ion (H_3O^+) concentration in a 0.30 M aqueous solution of the weak acid HCN(K_a=4.9 times 10^-10) at 25 degreeC. A buffer is created using acetic acid (HC_2H_3O_2) and sodium acetate (NaC_2H_3O_2).If a small amount of NaOH is added, which species will react with the hydroxide (OH) to keep the pH from changing? Which of these options will form the most effective buffer system with a pH value near 6.30? Complete the statement: The weak acid formic acid is titrated with a strong base. At the equivalence point of the titration, the solution___ A buffer made from equal amounts of nitrous acid and nitrite ion (HNO_2, NO_2) has a buffer capacity of 0.050 mol/L. If 0.035 mol of HCI is added to 150 ml. of the buffer solution, what will happen to the pH? (Assume the total buffer + acid volume is still close to 150 mL.)

Explanation / Answer

16)

[H3O+] = sqrt (Ka x C)

            = sqrt (4.9 x 10^-10 x 0.3)

            = 1.2 x 10^-5 M

17)

HC2H3O2 + OH-   ----------------------> C2H3O2Na + H2O

18)

here H2CO3 pKa value is

pKa = -log Ka = -log (4.3 x 10^-7)

       = 6.34.

this is nearer to pH value . so it is more suitable.

19)

it is salt of strong base. so this is more basic

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.