Question

in precision from two to four decimal places (figure 15.9)
the fact that ph is a logarithmic function has a huge impact on what a small change in ph truly means.
question 15.14
mark as: none
calculate h₃o⁺ for a solution of ph 4.3.
respond with the correct number of significant figures in scientific notation (use e notation and only 1 digit before decimal e.g. 2.5e5 for 2.5 x 10⁵)
type your numeric answer and submit
unanswered
submit
question 15.15
mark as: none
calculate h₃o⁺ for a solution of ph 5.3.
respond with the correct number of significant figures in scientific notation (use e notation and only 1 digit before decimal e.g. 2.5e5 for 2.5 x 10⁵)
type your numeric answer and submit

Explanation:

Step1: Recall pH formula

$\text{pH} = -\log_{10}[\text{H}_3\text{O}^+]$

Step2: Rearrange for $[\text{H}_3\text{O}^+]$

$[\text{H}_3\text{O}^+] = 10^{-\text{pH}}$
---

For Question 15.14 (pH=4.3):

Step3: Substitute pH=4.3

$[\text{H}_3\text{O}^+] = 10^{-4.3}$

Step4: Compute and format result

$10^{-4.3} = 5.01187 \times 10^{-5} \approx 5 \times 10^{-5}$ (1 significant figure, E notation: $5\text{E-5}$)
---

For Question 15.15 (pH=5.3):

Step3: Substitute pH=5.3

$[\text{H}_3\text{O}^+] = 10^{-5.3}$

Step4: Compute and format result

$10^{-5.3} = 5.01187 \times 10^{-6} \approx 5 \times 10^{-6}$ (1 significant figure, E notation: $5\text{E-6}$)

Answer:

Question 15.14: $5\text{E-5}$
Question 15.15: $5\text{E-6}$