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A 0.135 L volume of a 0.707 mol/L solution of sodium hydroxide, NaOH(aq), is diluted to a volume of 0.629 L. What is the pH of the diluted solution?

a) pH 1.95
b) pH 3.00
c) pH 9.00
d) pH 11.45

User Patchwork
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1 Answer

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Final answer:

To calculate the pH of the diluted solution, determine the concentration of hydroxide ions by using the equation c1v1 = c2v2. From there, calculate the pOH using the equation pOH = -log[OH-] and then find the pH using the equation pH + pOH = 14.

Step-by-step explanation:

To calculate the pH of the diluted solution, we need to find the concentration of hydroxide ions (OH-) first. Since sodium hydroxide is a strong base, it completely ionizes in water, so the concentration of OH- ions is equal to the concentration of the sodium hydroxide solution. The initial concentration is given as 0.707 mol/L, and the volume is 0.135 L. By diluting the solution to a volume of 0.629 L, the concentration of OH- ions remains the same, but the volume increases. Using the equation c1v1 = c2v2, we can calculate the new concentration:

c1 = 0.707 mol/L, v1 = 0.135 L, v2 = 0.629 L
c2 = (c1v1) / v2 = (0.707 mol/L x 0.135 L) / 0.629 L = 0.152 mol/L

To find the pH, we need to calculate the pOH. The pOH is calculated using the equation pOH = -log[OH-]. Therefore, pOH = -log(0.152) = 0.818. Finally, we can find the pH using the equation pH + pOH = 14. Thus, pH = 14 - 0.818 = 13.182.

User Karsas
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