P.s - Do don't just copy and paste the answer from the last chegg expert who answered this. He did not even answer it. Just copy and pasted the question. If you just copy their answer, it will be immediate downvote.

2. A hole must be wet-etched through a silicon wafer that is 700 pm thick. A mixture of two parts of HC H202, two parts of 49.2% HF, and six parts of 69.5% HNO, is mixed together to do the etch. (a) How long should the etch take? (b) The etch is found to take nearly twice as long as predicted. Assuming that the initial concentrations of the proper chemicals are used, list three things that might have caused the reduction in the apparent etch rate and what you would do to solve each one