Complete reaction of 2.0 g of calcium (at wt. = 40) with excess HCl produces 1.125 L of H2 gas. Complete reaction of the same quantity of another metal ‘‘M’’ with excess HCl produces 1.85 L of H2 gas under identical conditions. The equivalent weight of ‘‘M’’ is closest to :
(A) 23
(B) 9
(C) 7
(D) 12
