In the reaction Mg(s) + Br2() → MgBrz(s), what should be the coefficient for Br2?

A. 2
B. 4
C. 1
D. 3

1

Explanation:

Chemical equation:

Mg + Br₂  →  MgBr₂

Balanced chemical equation:

Mg + Br₂  →  MgBr₂

Left hand side                         Right hand side

Mg = 1                                         Mg = 1            

Br = 2                                          Br = 2

There are one Mg and 2 Br atoms on both side of equation thus this equation is balanced. Thus coefficient with bromine is 1.

Mg is present in group 2 it loses two valance electrons and get +2 oxidation state. Bromine is present in group 17 have 7 valence electrons. Thus one bromine atom need only one electron to complete the octet that's why two bromine atoms will attached with one magnesium atom to cancel the charge +2 and make the compound neutral.

it is reliable if two scientists recorded it