The circle at right represents a portion of a mixture of four gases: gas a (purple), gas b (brown), gas c (green), and gas d2 (orange). (a) which gas has the highest partial pressure? gas a has the highest partial pressure gas b has the highest partial pressure gas c has the highest partial pressure gas d2 has the highest partial pressure (b) which gas has the lowest partial pressure? gas a has the lowest partial pressure gas b has the lowest partial pressure gas c has the lowest partial pressure gas d2 has the lowest partial pressure (c) if the total pressure is 0.931 atm, what is the partial pressure of d2? atm