Calculate the content or concentration for each substance in the following mixtures.
(a) A solution that contains 250 mL of acetonitrile and 500 mL of methanol diluted with water to a total volume of 2.00 L
(b) A 15.2 g steel sample that contains 10.69 g iron, 2.67 g chromium, 1.22 g nickel, 0.306 g manganese, 0.153 g silicon and 0.122g carbon. What is the concentration of each substance
(c) A 5.00 L river-water sample that contains 25 g of dissolved solids