A paper coffee cup is lined with a thin layer of plastic to make it waterproof. This plastic makes
up 5% of the mass of the cup and has the following molecular structure.
960 dm3
of a gaseous hydrocarbon monomer (measured at room temperature and pressure)
was used to make a certain number of plastic-lined cups.
It is proposed that a more environmentally-friendly, biodegradable plastic, poly(lactic acid),
could be used instead in the same proportions by mass (5%). Assume that any polymerisation
reaction has a 100% yield.
What mass of lactic acid (Mr = 90) is required to make the same number of biodegradable
cups?
(Ar values: H = 1; C = 12; O = 16. Assume that one mole of a gas occupies 24 dm3
at room
temperature and pressure.)
A 896 g
B 1120 g
C 1200 g
D 1400 g
E 1500 g
F 3000 g
G 3600 g
The answer is F but I keep geting G