Suppose you are performing a gas-producing reaction with an unknown metal, x . x ( s ) + 2 h c l ( a q ) ⟶ x c l 2 ( a q ) + h 2 ( g ) a sample of 0.243 g of the unknown metal produces 76.9 ml of h 2 gas. the gas is collected over water at an atmospheric pressure of 768.3 mm hg at 23 oc, at which the vapor pressure of water is 21.1 mm hg. assume that the hydrogen gas behaves ideally. what is the experimental value for the molar mass of the metal in g/mol?