2) Explain why the water levels inside and outside the gas collection cylinder must be the same before the volume of gas is measured and recorded. 3) Suppose a student failed to account for the partial pressure of water in the gas collection cylinder. What effect would this have on the calculated value for the molar mass of butane? Justify you answer. 6) Suppose that the lighter used by a student in this experiment was not completely dry before its final mass was measured (after the gas had been added to the cylinder). What affect would this have on the student's calculated value for the molar mass of butane? Explain