An IV solution contains 135 mEq/L Na+, 45 mEq/L K+, and 12 mEq/L Ca2+. If HCO3- is the only anion in the solution what is its concentration in mEq/L?

I think the concentration in mEq/L is going to be 45

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.