What does the x represent on a motion map

The rules of engagement (roe) working group is often used to (select all that apply.)

The boiling point of propanoic acid is higher than that of 1-butanol because: propanoic acid has a higher molecular weight than 1-butanol. propanoic acid is more soluble in water than 1-butanol. propanoic acid is a better hydrogen bond donor than 1-butanol. propanoic acid forms hydrogen bonded dimers and 1-butanol does not. 1-butanol forms hydrogen bonded dimers and propanoic acid does not.

How many grams of co(g) are there in 74.5 ml of the gas at 0.933 atm and 30o c?