A chemist plots mass versus amount for two pure diatomic gases under identical conditions and obtains two lines with slopes of 28 g mol−1 and 32 g mol−1. The gases are N2 and O2. Which of the following correctly identifies the gas associated with each slope?
a) 28 g mol−1 → O2; 32 g mol−1 → N2
b) Both slopes could correspond to either gas because the graph alone cannot identify molecular identity.
c) 28 g mol−1 → N2; 32 g mol−1 → O2
d) Both slopes represent mixtures of N2 and O2 rather than pure gases.