Round Your Answer to the Nearest Tenth, When Appropriate $\mathrm { pH } = - \log \left[ \mathrm { H } _ { 3 } \mathrm { O } ^ { + } \right] , \text {as }$

Multiple Choice

Round your answer to the nearest tenth, when appropriate. Use the formula $\mathrm { pH } = - \log \left[ \mathrm { H } _ { 3 } \mathrm { O } ^ { + } \right] , \text {as }$ needed.
-Find the $\mathrm { pH }$ if $\left[ \mathrm { H } _ { 3 } \mathrm { O } ^ { + } \right] = 3.5 \times 10 ^ { - 7 }$ .

A) $6.7$
B) $7.5$
C) $6.5$
D) $- 7.5$