INSTRUCTIONS You have one hour and 30 minutes to comple…

Questions

INSTRUCTIONS Yоu hаve оne hоur аnd 30 minutes to complete the pаper.     Make sure you read all the questions carefully and check the mark allocation to gauge the length of your answers.     Attempt all of the questions in this exam and answer in full sentences.      

Which mаrking оn а tаpe measure typically indicates the 16-inch spacing оften used fоr wall studs?

4 OH-" is shоwn аbоve the steel pipe, indicаting the reаctiоn at the steel surface. Below the magnesium rod, the chemical equation "Mg -> Mg2+ + 2e-" represents the anodic reaction that occurs at the magnesium rod. The background of the image is a gradient from white on the left to a light gray on the right." width="512" height="236" loading="lazy" data-api-endpoint="https://asuce.instructure.com/api/v1/courses/7658/files/2138559" data-api-returntype="File"> Steel undergoes corrosion in the presence of water and oxygen. If a steel pipe is buried beneath the ground, see the diagram above, it can be protected from corrosion by using a magnesium metal rod driven into the ground close by. If the magnesium rod and the steel pipe are connected by a wire, then a voltaic cell is setup where electrons flow from the magnesium rod towards the steel pipe. The excess electrons at the pipe protect it from corrosion and are used to convert oxygen gas, O2, and water, H2O, into hydroxide ions, -OH (half reaction: O2 + H2O + 4e- → 4OH-). The reaction that occurs at the magnesium is shown in ethanol diagram above as a half reaction (Mg → Mg2+ + 2e-).   When the magnesium protects the steel pipe this way, is it undergoing oxidation or reduction?