A solution of MgCl2 which is equivalent to 100,000 mg/L as calcium carbonate. Express this concentration in N and M units. Atomic weights: Ca: 40, C: 12, O: 16
a. 2.48 N, 124.2 M
b. 2.5 N, 125 M
c. 3.2 N, 160 M
d. 3.6 N, 180 M