Question

tdsb.elearningontario.ca
dnesday - sem 1 - toronto dsb
0.22
question 2 (1 point) ✓ saved
the notation h₃o⁺ (aq) is sometimes simplified to which of the following?
h₂o (l)
h⁺ (aq)
h⁻ (aq)
oh⁺ (aq)
oh⁻ (aq)
question 3 (1 point)
use the following information to answer the next question.
the ph value of lime water is 10.5.
the hydronium ion concentration in a sample of lime water is:

Explanation:

Question 2

In aqueous solution, the hydronium ion $\ce{H3O+ (aq)}$ is often simplified to $\ce{H+ (aq)}$ because the $\ce{H+}$ (proton) is associated with a water molecule, but the notation $\ce{H+ (aq)}$ is a common simplification to represent the hydrated proton. The other options are incorrect: $\ce{H2O (l)}$ is water, $\ce{H- (aq)}$ is a hydride ion, $\ce{OH+ (aq)}$ is not a common species, and $\ce{OH- (aq)}$ is the hydroxide ion.

Step1: Recall the formula relating pH and hydronium ion concentration

The formula is $\text{pH} = -\log_{10}[\ce{H3O+}]$, where $[\ce{H3O+}]$ is the hydronium ion concentration in $\text{mol/L}$. We can rearrange this formula to solve for $[\ce{H3O+}]$: $[\ce{H3O+}] = 10^{-\text{pH}}$.

Step2: Substitute the given pH value

Given that the pH of lime water is $10.5$, we substitute into the formula: $[\ce{H3O+}] = 10^{-10.5}$.

Step3: Calculate $10^{-10.5}$

We know that $10^{-10.5}=10^{-10 - 0.5}=10^{-10}\times10^{-0.5}$. Since $10^{-0.5}=\frac{1}{\sqrt{10}}\approx0.316$, then $10^{-10.5}\approx3.16\times 10^{-11}\ \text{mol/L}$.

Answer:

B. $\ce{H+ (aq)}$ (assuming the options are labeled with B as the correct one here, based on the checkmark in the image)

Question 3