A 135 mg sample of a metal alloy containing Cu (63.55 g/mol) was dissolved in acid and diluted to a volume of 250.0 mL. Measurement with a Cu+ ISE resulted in a potential of -86.0 mV. Exactly 5.00 mL of 1.00 x 10-2M Cut standard was added to the 250.0 mL solution and the potential on the ISE became -52.7 mV. Calculate the percentage of copper in the alloy.

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.