The Chemical Acidity of a Solution Is Measured in Units $\mathrm { pH } = - \log \left[ \mathrm { H } ^ { + } \right]$

Multiple Choice

The chemical acidity of a solution is measured in units of pH: $\mathrm { pH } = - \log \left[ \mathrm { H } ^ { + } \right]$ ,where $\left[ \mathrm { H } ^ { + } \right]$ is the hydrogen ion concentration in the solution.What is $\left[ \mathrm { H } ^ { + } \right]$ if the $\mathrm { pH } = 3.8$ ?

A) 3.800
B) $6.31 \times 10 ^ { - 4 }$
C) $6.31 \times 10 ^ { - 3 }$
D) $1.58 \times 10 ^ { - 3 }$
E) $1.58 \times 10 ^ { - 4 }$