I am trying to do a dilution where I know I have 0.749 g/ mL and I want to use this concentration to calculate the grams of aspirin in each 100 mL solution. I am specifically worried about the units. I want grams out. Is it valid to do the following? One: $$C1V1=C2V2$$ $$(0.749 g)(1 mL)=(C2 g)(100mL)$$ $$C2=0.00749 g$$
or must I do this? Two: $$C1V1=C2V2$$ $$(0.749 g/mL)(1 mL)=(C2 g/mL)(100mL)$$ $$C2=0.00749 g/mL$$
The difference being the final units. g vs. g/mL