Determine how much more intense is an earthquake whose magnitude is $7.8$ on the Richter scale than an earthquake whose magnitude is $6.2$. [Use ${10}^{1.6}=39.810$]

The $pH$ value of a solution is used to determine whether a solution is basic (alkaline) or acidic. A $pH$ value of $7$ is neutral, less than $7$ is acidic, and more than $7$ is basic. To calculate the $pH$ of a liquid you need to know the concentration of hydrogen ions $\left(H^{+}\right)$ in moles per litre (mol/l) of the liquid. The $pH$ is then calculated using the logarithmic formula: $pH=-{\log }_{10}\left(H^{+}\right)$.

Milk has $H^{+}=1.58\times {10}^{-7} \text{mol/l}$. Determine whether milk is acidic or basic. [Use $\log 1.58=0.198$]

The $pH$ value of a solution is used to determine whether a solution is basic (alkaline) or acidic. A $pH$ value of $7$ is neutral, less than $7$ is acidic, and more than $7$ is basic. To calculate the $pH$ of a liquid you need to know the concentration of hydrogen ions $\left(H^{+}\right)$ in moles per litre (mol/l) of the liquid. The $pH$ is then calculated using the logarithmic formula: $pH=-{\log }_{10}\left(H^{+}\right)$.

Find the $pH$ of vinegar with concentration: $H^{+}=1.58\times {10}^{-3} \text{mol/l}$. [Use $\log 1.58=0.198$]

The $pH$ value of a solution is used to determine whether a solution is basic (alkaline) or acidic. A $pH$ value of $7$ is neutral, less than $7$ is acidic, and more than $7$ is basic. To calculate the $pH$ of a liquid you need to know the concentration of hydrogen ions $\left(H^{+}\right)$ in moles per litre (mol/l) of the liquid. The $pH$ is then calculated using the logarithmic formula: $pH=-{\log }_{10}\left(H^{+}\right)$.

A sample of pool water has concentration: $H^{+}=6.3\times {10}^{-7} \text{mol/l}$. Determine the $pH$ of the sample of pool water. [Use $\log 6.3=0.778$]

The $pH$ value of a solution is used to determine whether a solution is basic (alkaline) or acidic. A $pH$ value of $7$ is neutral, less than $7$ is acidic, and more than $7$ is basic. To calculate the $pH$ of a liquid you need to know the concentration of hydrogen ions $\left(H^{+}\right)$ in moles per litre (mol/l) of the liquid. The $pH$ is then calculated using the logarithmic formula: $pH=-{\log }_{10}\left(H^{+}\right)$.

Some chemicals are added to the water. A sample of water is taken after adding the chemicals, and now the concentration is $H^{+}=7.94\times {10}^{-8} \text{mol/l}$. Determine if the water is now within optimal levels: $7.0<pH<7.4$. [Use $\log 7.94=0.899$]

The $pH$ value of a solution is used to determine whether a solution is basic (alkaline) or acidic. A $pH$ value of $7$ is neutral, less than $7$ is acidic, and more than $7$ is basic. To calculate the $pH$ of a liquid you need to know the concentration of hydrogen ions $\left(H^{+}\right)$ in moles per litre (mol/l) of the liquid. The $pH$ is then calculated using the logarithmic formula: $pH=-{\log }_{10}\left(H^{+}\right)$.

Find the values for $H^{+}$ that give a $pH$ in the range $7.0<pH<7.4$.

The volume of sound $D$ is measured in decibels $\left(db\right)$ and $I$ is the intensity of the sound measured in ${\text{Watts/m}}^2$, using the formula $D=10{\log }_{10}I$. An anti-theft car alarm has an intensity of $5.8\times {10}^{13} \mathrm{W}/{\mathrm{m}}^2$. Find the volume of the alarm in decibels. [Use $\log 5.8=0.763$]

The volume of sound $D$ is measured in decibels $\left(\mathrm{db}\right)$ and $I$ is the intensity of the sound measured in ${\text{Watts/m}}^2$, using the formula $D=10{\log }_{10}I$. Jill's scream measured $56\mathrm{db}$, and Jack's was $48\mathrm{db}$. Find how much more intense Jill's scream was than Jack's. [Use ${10}^{0.8}\simeq 6.3$]