A gas collecting tube full of water is inverted in a beaker of water in which a reaction is taking place. The water level in the tube is at 200.0 ml at the beginning of the experiment, and at 125.0 ml, at the end. the pressures is 750.0 mm Hg and the temperature is 85.0 Celsius. Calculate the volume of a gas collected corrected to S.T.P.. This is an review from last year and I cant exactly remember how to solve this.