Can anyone check my work/ me figure out how to do this?

determine the ph of the following solution.

a 4.5 x 10^-3 m hbr solution

my work:
all i did was -log(4.5x10^-3) and got 2.35 but i am not sure at all how to do this

What will most likely happen when two bromine atoms bond together?

Achemistry student needs to standardize a fresh solution of sodium hydroxide. he carefully weighs out of oxalic acid , a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in of distilled water. the student then titrates the oxalic acid solution with his sodium hydroxide solution. when the titration reaches the equivalence point, the student finds he has used of sodium hydroxide solution.calculate the molarity of the student's sodium hydroxide solution. be sure your answer has the correct number of significant digits.

What four properties do all waves have in common