Question

Which of the equations below represents the correct BALANCED equation?

a. Mg (s) + HCl (aq) --> MgCl2 (aq) + H2 (8)
b. Mg (s) + 2HCl (aq) --> MgCl2 (aq) + H2 (8)
c. 2Mg (s) + HCI (aq) --> MgCl2 (aq) + H2 (8)
d. 2Mg (s) + 2HCl (aq) --> MgCl2 (aq) + H2 (8)

Answer 1

b. Mg (s) + 2HCl (aq) --> MgCl2 (aq) + H2

Step-by-step explanation:

A subscript applies only to the element it is attached to while coefficients apply to all elements in a compound.

"a" has 1 atom of each element on the left but 2 Cl on the right.

"c" has 2 Mg, 1 H, & 1 Cl on the left but 1 Mg, 2 H, and 2 Cl on the right.

"d" has 2 atoms of each element on the left but only 1 Mg on the right.

"b" is the only answer with equal numbers of atoms on the right and left sides of the equation.