To calculate the $pH$ of a liquid you need to know the concentration of hydrogen ions $\left(H^{+}\right)$ in moles per liter of the liquid. The $pH$ is then calculated using the logarithmic formula $pH=-{\log }_{10}\left(H^{+}\right)$.  $HCI$ is a strong acid with a hydrogen ion concentration of $0.0015$ moles per liter. Find the $pH$ of the $HCI$ solution.  [Use ${\log }_{10}15=1.17609125906$]

To calculate the $pH$ of a liquid you need to know the concentration of hydrogen ions $\left(H^{+}\right)$ in moles per liter of the liquid. The $pH$ is then calculated using the logarithmic formula $pH=-{\log }_{10}\left(H^{+}\right)$. Find the hydrogen ion concentration of a liquid which has a $pH$ of $9.4$.

To calculate the $pH$ of a liquid you need to know the concentration of hydrogen ions $\left(H^{+}\right)$ in moles per liter of the liquid. The $pH$ is then calculated using the logarithmic formula $pH=-{\log }_{10}\left(H^{+}\right)$. A solution is said to be neutral (neither an acid nor a base) if its $pH$  is $7$ . Find the concentration of hydrogen ions which would be considered to be neutral.

The $pOH$ of an aqueous solution measures the number of hydroxide ions $\left(O{H}^{-}\right)$ in a solution, using the formula $pOH=-{\log }_{10}\left(O{H}^{-}\right)$. Find the $pOH$ of an aqueous solution that has a hydroxide ion concentration of $6.1\times {10}^{-5}$ moles per liter.  [Use ${\log }_{10}6.1=0.785329835011$]

The $pOH$ of an aqueous solution measures the number of hydroxide ions $\left(O{H}^{-}\right)$ in a solution, using the formula $pOH=-{\log }_{10}\left(O{H}^{-}\right)$. Find the hydroxide ion concentration in an aqueous solution that has a $pOH$ of $2.3$.

The decibel scale measures the intensity of sound $D$ using the equation $D=10\log I$, where $I$ is the intensity ratio of a sound.

On the decibel scale, the purr of a cat measures $D=10\log 330=25.2(3 \text{s.f})$ decibels.

Sound intensity is measured on a traffic light system:

Green: no ear protection needed. $1-75 DB$

Orange: ear protection recommended. $80-120 DB$

Red: ear protection necessary. $120+ DB$. Calculate the sound intensity of the following noise and determine whether or not ear protection equipment is recommended or necessary. 

A Chainsaw has an intensity ratio of $1.04\times {10}^{11}$.  [Use $\log 1.04=0.0170333393$]

The decibel scale measures the intensity of sound $D$ using the equation $D=10\log I$, where $I$ is the intensity ratio of a sound.

On the decibel scale, the purr of a cat measures $D=10\log 330=25.2(3 \text{s.f})$ decibels.

Sound intensity is measured on a traffic light system:

Green: no ear protection needed. $1-75 DB$

Orange: ear protection recommended. $80-120 DB$

Red: ear protection necessary. $120+ DB$. Calculate the sound intensity of the following noise and determine whether or not ear protection equipment is recommended or necessary. 

A flowing river has an intensity ratio of $3100000$.  [Use $\log 3.1=0.491361694$]

The decibel scale measures the intensity of sound $D$ using the equation $D=10\log I$, where $I$ is the intensity ratio of a sound.

On the decibel scale, the purr of a cat measures $D=10\log 330=25.2(3 \text{s.f})$ decibels.

Sound intensity is measured on a traffic light system:

Green: no ear protection needed. $1-75 DB$

Orange: ear protection recommended. $80-120 DB$

Red: ear protection necessary. $120+ DB$. Calculate the sound intensity of the following noise and determine whether or not ear protection equipment is recommended or necessary. 

A rocket launching has an intensity ratio of $8.2\times {10}^{16}$.  [Use $\log 8.2=0.913813852384$]