At STP conditions the volume of 1 mol of any ideal gas will be 22.4L
0.500 mol C3H3 x 22.4L / 1 mol = 11.2 L
A asystem at equilibrium stops
Get a magnet in a bag (inside out) and move the magnet all over the sand/iron and you can collect all the iron and turn the bag right side out and zip up the bag. Now you have the sand and iron separated and it will be harder to accidentally mix them later.
Answer: Objects with like charge repel each other.