Question

Question #67a20

Answer 1

B

Explanation:

`"Percent of element by mass" = ("Total mass of element")/("Total mass of compound")*100`

For `M_2O_3`, we have `53=(2M)/(2M+3(16))*100=(2M)/(2M+48)*100`

`(2M)/(2M+48)=53/100=0.53`

`2M=0.53(2M+48)=1.06M+25.44`

`2M-1.06M=0.94M`

`0.94M=25.44`

`M=25.44/0.96=26.5~~27`

`27 = B`