Question

calcule a massa molar da seguinte substancia Na2Co3

Answer 1

Na = 2 x 23  = 46
C   = 1 x 12  = 12
O   = 3 x 16  = 48

Total: 106 g/mol

Answer 2

$Na_{2} = 2*23=46$
$C=1*12=12$
$O_{3}=3*16=48$
$46+12+48=106g/mol$