Question

1 - Qual alternativa corresponde à massa molar do C₂H₆? ( utilize as massas atômicas: C=12, H=1) *
Me ajudem pfv

a) 26 g/mol
b) 30 g/mol
c) 32 g/mol
d)38 g/mol

2 - Descubra a massa molar do etanol C₂H₆O, e assinale a alternativa correta: ( C=12, H=1, O=16 ) *

a) 56 g/mol
b) 46 g/mol
c) 48 g/mol
d) 54 g/mol

3 - A massa molar do Ca(OH)2 é igual a: (Utilize as massas: Ca=40, O=16, H=1) *

a) 40 g/mol
b) 57 g/mol
c) 58 g/mol
d) 74 g/mol

Answer 1

Resposta:1)b) 30 g/mol

                2)b) 46 g/mol

                3)d) 74 g/mol

Explicação:

1)C2H6-->12x2+1x6-->24+6-->30 g/mol

2)C2FH6O-->12x2+1x6+16x1-->24+6+16-->46 g/mol

3)Ca(OH)2-->40x1+16x2+1x2-->40+32+2-->74 g/mol