Solve the Problem $\mathrm { pH } = - \log _ { 10 } \left[ \mathrm { H } ^ { + } \right]$

Multiple Choice

Solve the problem.
- $\mathrm { pH } = - \log _ { 10 } \left[ \mathrm { H } ^ { + } \right]$ Find the $\left[ \mathrm { H } ^ { + } \right]$ if the $\mathrm { pH } = 1.4$ .

A) $2.51 \times 10 ^ { - 1 }$
B) $3.98 \times 10 ^ { - 1 }$
C) $3.98 \times 10 ^ { - 2 }$
D) $2.51 \times 10 ^ { - 2 }$