Question

ph measures the acidity of a substance, and is described by the equation ph = -log(h+), where h+ is the concentration of hydrogen ions. a substance has an h - concentration of 4×10^(-4). find its ph to the nearest hundredth, then determine if it is basic, neutral, or acidic. the table below characterizes the acidity of a substance based on its ph. ph acidity: ph<7 acidic; ph = 7 neutral; ph>7 basic

Explanation:

Step1: Recall pH formula

The formula for pH is $pH = -\log(H^{+})$, where $H^{+}=4\times 10^{-4}$.

Step2: Substitute the value of $H^{+}$ into the formula

$pH=-\log(4\times 10^{-4})$. Using the logarithm property $\log(ab)=\log(a)+\log(b)$, we have $pH=-(\log(4)+\log(10^{-4}))$. Since $\log(10^{-4})=- 4$ and $\log(4)\approx0.6021$, then $pH=- (0.6021 - 4)$.

Step3: Simplify the expression

$pH=-0.6021 + 4=3.3979\approx3.40$.

Step4: Determine the nature of the substance

Since $pH = 3.40<7$, the substance is acidic.

Answer:

The pH of the substance is approximately $3.40$ and the substance is acidic.