What is the molar mass of Mn2Se7 ? A.) 601.34 g/mol

B.) 542.50 g/mol

C.) 662.60 g/mol

C.  662.60

Explanation:

the mass of Mn is about 54 grams/mol, (multiply that by 2 since there are 2 Mn's).

the mass of Se is about 79 grams/mol, so multiply that by 7

if you add them, you get 662.60 (approxamitly)

C) 662.60

Explanation:

~~55*2 + 79*7 = 110 + 553 = 663 (~~662.60)