Asolution contains 0.750 g of mg2 in enough water to make a 1875 ml solution. what is the milliequivalents of mg2 per liter (meq/l) for this solution

The answer is "32.9 meq/liter".
1875ml = 1875 / 1000 = 1.875ml
mass of magnesium = 24.305 g
0.750 g Mg²+ x 1 mole Mg²⁺/24.305 g x 2 equivalents/mole
= 0.617 equivalents0.0617 eq x 1000 meq/eq = 61.7 meq37.4 meq/1.875 L = 32.9 meq/liter

That result from subduction of oceanic plates beneath lighter continental plates. most of the earth's volcanoes are located around the pacific ring of fire because that the location of most of the earth's subduction zones.